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A |\ I n^~r Natural Resources 

Conservation Service 

Montana 

Water Supply Outlook 

June 1 st , 2019 


USDA 



Report 



Installed in September of 2018, the JL Meadow SNOTEL site was the first SNOTEL site installed in the U.S. 
that went directly to transmitting via the GOES (Geostationary Operating Environmental Satellite) 
System. In 2018, 28 SNOTEL sites were moved to this new telemetry system for testing through the winter 
of 2018/2019, and the results have been excellent. As a result, during the summer of 2019 the NRCS 
Montana Snow Survey will be upgrading all SNOTEL sites in Montana with new dataloggers and new 
telemetry systems (cellular or satellite communications). This move to modernize the system is being made 
to provide more reliable snowpack and mountain weather information for our customers in the future. 


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For more water supply and resource management information, contact: 


Lucas Zukiewicz 

Water Supply Specialist 
Federal Building 
10 East Babcock, Room 443 
Bozeman, MT 59715 
Phone 406-587-6843 
lucas.zukiewicz@mt.usda.gov 

http://www.nrcs.usda.gov/wps/portal/nrcs/main/mt/snow/ 


Montana Water Supply Outlook Report as of June 1 st , 2019 


How Forecasts Are Made 

Most of the annual streamflow in the Western United States originates as snowfall that has accumulated high in 
the mountains during winter and early spring. As the snowpack accumulates, hydrologists estimate the runoff 
that will occur when it melts. Predictions are based on careful measurements of snow water equivalent at 
selected index points. Precipitation, temperature, soil moisture and antecedent streamflow data are combined 
with snowpack data to prepare runoff forecasts. Streamflow forecasts are coordinated by Natural Resources 
Conservation Service and National Weather Service hydrologists. This report presents a comprehensive picture 
of water supply conditions for areas dependent upon surface runoff. It includes selected streamflow forecasts, 
summarized snowpack and precipitation data, reservoir storage data, and narratives describing current 
conditions. 

Snowpack data are obtained by using a combination of manual and automated SNOTEL measurement methods. 
Manual readings of snow depth and water equivalent are taken at locations called snow courses on a monthly 
or semi-monthly schedule during the winter. In addition, snow water equivalent, precipitation and 
temperature are monitored on a daily basis and transmitted via meteor burst telemetry to central data 
collection facilities. Both monthly and daily data are used to project snowmelt runoff. 

Forecast uncertainty originates from two sources: (1) uncertainty of future hydrologic and climatic conditions, 
and (2) error in the forecasting procedure. To express the uncertainty in the most probable forecast, four 
additional forecasts are provided. The actual streamflow can be expected to exceed the most probable forecast 
50% of the time. Similarly, the actual streamflow volume can be expected to exceed the 90% forecast volume 
90% of the time. The same is true for the 70%, 30%, and 10% forecasts. Generally, the 90% and 70% forecasts 
reflect drier than normal hydrologic and climatic conditions; the 30% and 10% forecasts reflect wetter than 
normal conditions. As the forecast season progresses, a greater portion of the future hydrologic and climatic 
uncertainty will become known and the additional forecasts will move closer to the most probable forecast. 


The United States Department of Agriculture (USDA) prohibits discrimination in its programs on the basis of race, color, national origin, sex, religion, age, 
disability, political beliefs and marital or familial status. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means 
for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at 
(202) 720-2600 (voice and TDD). 

To file a complaint, write the Secretary of Agriculture, U.S. Department of Agriculture, Washington, D.C., 20250, or call 1-800-245-6340 (voice) or 
(202) 720-1127 (TDD). USDA is an equal employment opportunity employer. 

r\i 


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Snowpack - Overview 

Let's start this month's report with the most interesting subject possible, statistics. It bears discussing because looking at 
snowpack percentages on June 1st can be a little misleading. When looking at snowpack totals in this report, or on the 
online maps and reports, it's important to remember that it is being compared to this date, and not the peak snowpack 
for the year. The snow has been actively melting throughout May, and high percentages shouldn't be cause for alarm. In 
some basins, mostly west of the Divide, most of the snowpack has typically melted at monitoring locations with about 
one-third to half of the basin-wide annual peak snowpack remaining to melt at higher elevations. In southern Montana, 
where higher elevation helps to sustain snowpack a bit longer, about half of the snowpack is typically remaining to melt 
at mid and high elevations. 

Putting these statistics into context, this month snowpack percentages are below average for this date in northwest 
river basins, meaning that melt out is ahead of schedule, amplified by the above average temperatures during the 
month of May. Snowpack in central and southern basins benefitted by the cool weather during the third week of May, 
which helped to prolong snowmelt, resulting in snowpack that is above normal for June 1st. So, there is good news and 
bad news hidden in these numbers. 

Well-above average temperatures during the last week of May (and first week of June) have once again accelerated 
snowmelt in the mountains. Rivers on the east side of the Divide are once again on the rise and will likely experience 
their snowmelt-driven peak flows during the next seven to fourteen days. 


Snow Water Equivalent 


6/1/2019 

% Normal 

% Last Year 

Columbia River Basin 

75 

65 

Kootnenai in Montana 

43 

43 

Flathead in Montana 

71 

62 

Upper Clark Fork 

93 

66 

Bitterroot 

74 

65 

Lower Clark Fork 

92 

62 

Missouri River Basin 

132 

138 

Jefferson 

120 

118 

Madison 

138 

141 

Gallatin 

140 

143 

Headwaters Mainstem 

122 

122 

Smith-Judith-Musselshell 

157 

253 

Sun-Teton-Marias 

82 

99 

St. Mary-Milk 

73 

72 

Yellowstone River Basin 

176 

168 

Upper Yellowstone 

133 

114 

Lower Yellowstone 

254 

302 


West of Divide 

75 

65 

East of Divide 

150 

150 

Montano State-Wide 

104 

94 







Nortb Dakota 


Plentywooc 


Kootenai 

43 % 


/ 

Whitefish 
Kalis peH 


Sf Mary’s 

Ha/ re ^ 

Milk 
73 % { 


Glasgow 


Flathead 

Poison 


Coeur d’Alene 


Lowert 
Clark 
^fork 


fainstei 


Glendive 


Smith- 

Judith- 

Musselshell 

157 % 


Lewi st own 


Upper Clark 


lelena 


o Hamilti 


I North ^kota. 

C^Soutb Dakota 


Kingston 


Jefferson 


Upper 

Yellowstone 

133 % 


DHIon 


1 M° ntan|.t 
^^n1ng| 


Belle Fourche 


Lower 
Yellowstoi 
Borland 254 % 


Rex burg 


Rv erton 


USDA 


Mcnfcuia Suie Uniry 

i Natural Resource 
Information System 


Montana Data Collection Office 
Current Snow Water Equivalent 
Basin Percentage of Normal - June 1, 2019 


Williston 

. 


Percent of Normal 


150 % 

□ 131 - 150 % 
1 1 111 - 130 % 

]] 91 - 110 % 

| | 71 - 90 % 

[] 51 - 70 % 

| 1 - 50 % 

1 0 % 




T7 ^ 






Note: Data includes SNOTEL and Snow course Measurements on June 1, 2019 


Page4 





























Montana Data Collection Office 
Current Snow Water Equivalent 
June 1,2019 



— 


North Dakota 


PWADA 


Plentywood 


St Mary's- 


Kootenai 5 

'•'V \ Kalis pell 


Sun-Teton-Marias 


Glasgow 


Coeur d’Alene 


-i Lower 
citirkf-orl 


Flathead 


Glendivi 


Lewistown 


Smith-Judith- 

Musselshell 


Upper 


Bitterroot 


dngstofi 


Montan 


Wyoming 


Sheridan 


Belle Fourche 


Jefferson 


Sturgis 


Lower 

Yellowstone 


Worlancf 


Rex burg 


Rwerton 


USDA 


Mo nuns Sate Lfcmry 

i Natural Resource 
Information System 


Idaho 


Williston 


i North Dakota 

Fsouth Dakota 






Percent of Normal 

SNOTEL 

SNOWCOURSE 

• 

+ 

>150% 

• 

* 

131 - 150% 

o 

* 

111 -130% 

• 


91 - 110% 

© 

* 

71 -90% 

• 

# 

51 - 70% 

• 

+ 

1 - 50% 

* 

* 

0% 


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Montana Data Collection Office 
Sub-Basin Snow Water Equivalent - June 1st, 2019 



V Havre 


Shelby 


Kalispell 68%\^ 59% 


o/Choteau 


Thompson rails 


Great Falls 


iwistown 


Helens 

gP 7 % -|02%eJod^22% 


White Sulphur Springs 
■ Jk Harlowton 


Roundup 


ilder«Townsel 


Big Timber 


Billings* 


Hardin 


Columbus 


Powell 


>heridan 


Buffalo 


Worland 


Therm opolis 


Riverton 


Lander 


USDA 


Snow Water Equivalent 

% Normal 

Snow Free 
<50% 

50 to 69% 

70 to 89% 

90 to 109% 

I 110 to 129% 

130 to 149% 

>150% 


Prepared by: 

NRCS Montana Snow Survey Staff 
Bozeman, MT 


Continental Divide https://www.nrcs.usda.gov/wps/portal/nrcs/mt/snow/ 


Page 


6 












Precipitation - Overview 

May of 2019 can be best described as feast or famine. The first two weeks of the month were very dry across all of the 
western half of the state, with mountain and valley locations recording minimal precipitation during the period. The 
weather patterns changed mid-month with low-pressure systems dominating the weather across the western and 
central united states. This typical spring weather pattern favors some locations in the state over others, the east facing 
basins (along the plains) tend to receive the most precipitation from the counterclockwise rotation of low-pressure 
systems and resulting upslope flow. Precipitation totals during the last fourteen days of the month along the Rocky 
Mountain Front ranged from 4.3" to 9.0", which caused quick and significant increases in river volumes with flooding 
widespread in many areas. 

While the latter half of the month did yield some precipitation in other parts of the state, it wasn't enough to make up 
for the early month deficit, and monthly precipitation ended up being below average in most western mountain and 
valley locations. Most river basins in central and southern Montana have water year precipitation totals that remain 
near to slightly above average, due to the winter snowfall and April precipitation. However, the northwest corner of the 
state made further declines in water year totals during the month due to well below average precipitation during May in 
the Kootenai (44%) and Flathead (58%) River basins. This is an area to keep an eye on this summer, as decreased spring 
and early summer precipitation increases the demand for irrigation water. This water year has been one of extremes, so 
hopefully, June yields closer to average precipitation across the state. 


Precipitation 


6 / 1/2019 

Monthly % Avg 

Water Year % Avg 

WY % Last Year 

Columbia River Basin 

71 

91 

76 

Kootnenai in Montana 

44 

76 

70 

Flathead in Montana 

58 

88 

73 

Upper Clark Fork 

90 

99 

77 

Bitterroot 

67 

99 

84 

Lower Clark Fork 

77 

92 

81 

Missouri River Basin 

93 

108 

92 

Jefferson 

86 

101 

90 

Madison 

86 

111 

98 

Gallatin 

74 

113 

93 

Headwaters Mainstem 

91 

107 

81 

Smith-Judith-Musselshell 

93 

105 

87 

Sun-Teton-Marias 

174 

107 

84 

St. Mary-Milk 

62 

85 

76 

Yellowstone River Basin 

155 

113 

93 

Upper Yellowstone 

102 

111 

83 

Lower Yellowstone 

189 

113 

100 


West of Divide 

71 

91 

76 

East of Divide 

120 

108 

91 

Montana State-Wide 

93 

102 

84 




Montana Data Collection Office 
Monthly Precipitation 

Basin Percentage of Normal - June 1, 2019 (May 1, 2019 - June 1, 2019) 



North Dakota 


CANADA 


Plentywood 


Kootenai 

44 % 


Whitefish 


Kalis pell 


Glasgow 


Flathead 

Poison 58% 


Lower^ 
Clark 
.Fork < 


Coeur d'Alene 


fa ins tei 


Glendive 


Smith- 

Judith- 

Musselshell 

93 % 


Upper Clark 


I North Dakota 
ysSu^Dakoto 


Laurel 


Upper 

Yellowstone 


Dillon 


102 % 


leridan 


Belle Fourche 


Lower 
Yellowsto i 
Worland 189 % 


Rex burg 


Idaho Falls 


Riverton 


USDA 


Ucndna Stetc Lfcniy 

i Natural Resource 
Information System 


Williston 


Percent of Normal 




> 150 % 


131 - 150 % 
111 - 130 % 
91 - 110 % 
71 - 90 % 
51 - 70 % 
1 - 50 % 
0 % 


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Montana Data Collection Office 
Monthly Precipitation 

Percentage of Normal - June 1, 2019 (May 1, 2019 - June 1, 2019) 



’CfrWADA 


St Marys 


Plentywooi 


Kootenai 


Sun- Teton-Marias 


lasgow 


Coeur d’Alene 


Poison 


-itower 

ciark-forl 


Glendivi 


Mamstem 

(Missouri) 

> Helena \ 


;wistown 


Smith-Judith- 

Musselshell 


I O Hamilti 

s • j 


! North Dakota 
• soof Dakota 


r-' Upper 
Yellowstone 


Bitterroot 


Madisi 


Montan 


Wyoming 


Belle Fourche 


Jefferson •< 


Lower • 
Yellowstone 


ivorland^ 


Rex burg 


Idaho Falls 


: 'erton 


USDA 


M«n<»na Sate Hinny 

i Natural Resource 
Information System 


North Dakota 


Idaho 


^Williston 


Percent of Normal 

SNOTEL COOP/ACIS 


# >150% 

<•) 131-150% 

® 111-130% 

® 91-110% 

® 71-90% 

® 51 - 70% 

# 1 - 50% 


Page 














CANADA 


St Mary's 


Kootenai 

76 % 


Whitefish 


Kalis pell 


Glasgow 


Flathead 

Poison 


Lower 
Clark 
Jork < 


Coeur d’Alene 


Hea dw ah 

itffainstei 


Glendive 


Smith- 
Judith- 
Musselshell 
105 % 


Lewi st own 


Upper Clark 


jo Hamilton 

i iiierrdot 


LaureJ 


Upper^~ 

Yellowstone 

111 % 


Montan 


Sheridan 


Belle Fourche 


Sturgis 


Lower \ 
Yellowstone \ 
Worland 113 % 


Rex burg 


Idaho Fans 


Riv erton 


USDA 


Montana State Unary 

I N aturalRcBOurce 
Information System 


Montana Data Collection Office 
Water Year to Date Precipitation 
Basin Percentage of Normal - June 1, 2019 


-_ 

_P Horlli lidkoLj 

Plentywood | 


i North Dakota 


Percent of Normal 




/ 


H >150% 

□ 131 - 150 % 
^ 111 - 130 % 

| | 91 - 110 % 

| 1 71 - 90 % 

]] 51 - 70 % 

| 1 - 50 % 

1 0 % 






Page 10 


























Montana Data Collection Office 
Water Year to Date Precipitation 
Percentage of Normal - June 1, 2019 



— 


North Dakota 


CAffADA 


0 Plentywoo^ 


St Mary's 


Kootenai 


Sun-Teton-Marias 


Coeur d'Alene 


Poison 


-^Lower 

cihrk'Forl 


Glendivi 


>wist own 


Smith-Judith- 
© Musselshell 


f O Hamilti 


! North J)akota 

0South Dakota 


# Yellowstoni 


Bitterroot 


Montan 


Wyoming 


Sheridan 


Belle Fourche 


Jefferson c 


Lower © 
Yellowstone 


Worland^ 


Rex burg 


[Casper 


USDA 


Mcnona Suic Lkrsiy 

i Natural Resource 
Information System 


Idaho 


Williston 


Percent of Normal 

SNOTEL COOP/ACIS 

• 

# 

> 150% 

• 

0 

131 - 150% 

o 

0 

111 -130% 

© 

0 

91 - 110% 

0 

0 

71 - 90% 

• 

0 

51 - 70% 

• 

# 

1 - 50% 


Page 11 
















Reservoirs - Overview 


As of June 1 st , most reservoirs across the state are approaching full, or are full and spilling. The snowpack this year 
sufficient to fill most reservoirs, and summer water supply from reservoirs looks to be adequate in most locations. 


Reservoir Storac 

ie 

6/1/2019 

% Average 

% Capacity 

% Last Year 

Columbia River Basin 

107 

79 

93 

Kootnenai in Montana 

106 

69 

88 

Flathead in Montana 

109 

89 

98 

Upper Clark Fork 

108 

93 

92 

Bitterroot 

108 

106 

100 

Lower Clark Fork 

102 

98 

100 

Missouri River Basin 

124 

88 

99 

Jefferson 

116 

72 

91 

Madison 

95 

84 

90 

Gallatin 

120 

101 

101 

Headwaters Mainstem 

128 

91 

98 

Smith-Judith-Musselshell 

149 

104 

101 

Sun-Teton-Marias 

119 

75 

106 

St. Mary-Milk 

133 

74 

96 

Yellowstone River Basin 

109 

69 

96 

Upper Yellowstone 

119 

103 

100 

Lower Yellowstone 

108 

68 

96 


West of Divide 

107 

79 

93 

East of Divide 

123 

87 

98 

Montano State-Wide 

118 

85 

97 





CANADA 


Plentywood 


St Mary's 


Kootenai 


Whitefish 


Glasgow 


Sun- Teton-Marias 


Coeur d'Alene 


pwer S Flathead 


Glendivi 


Upper 

Clark Fork / 
□ l 


Lewi st own 


Smith-Judith- 

Musselshell 


Nprth Dakota 

South Dakota 


Biker root 


Jefferson 


Upper 

Yellowstone 


Montaft 


Sheridan 


Belle Fourche 


Sturgis 


Lower 

Yellowstone . Wortan * 


Rex burg 


Riverton 


USDA 


Montana Sate Ht*iy 

i Natural Resource 
Information System 


Montana Data Collection Office 
Reservoir Levels 

Percentage of Normal - June 1, 2019 


-North Dakota 


f Idaho 


?! 

r 

| !| Williston 

s?. 




Reservoirs 

Percent of Normal 

■ >150% 

□ 131-150% 

□ 111-130% 

□ 91 - 110% 

□ 71 - 90% 

■ 51 - 70% 

■ 1 - 50% 














3 .£? 


Page 


13 




















Streamflow - Overview 


It's that time of the year that Snow Hydrologists live for, the seasonal snowmelt runoff! Spring and early summer are 
when all the real action happens across the state of Montana, and this year hasn't disappointed, so far. Rivers across the 
state began their seasonal rises from snowmelt in April, which continued through May when all elevations started to 
melt, causing significant increases in river volumes. Many rivers west of the Continental Divide likely experienced their 
snowmelt-driven peak flows between May 17th and May 19th, after a period of dry and warm weather caused rapid 
melt across the state, which was followed by a moderate rain event. 

Peak flows in the river flowing from the Rocky Mountain Front likely occurred during the end of May, due to a significant 
rain event, which added a large amount of water to rivers which were already high from snowmelt. These peaks 
occurred during the Memorial Day weekend with many peaks occurring on Memorial Day. This is the second year in a 
row where a significant rain event has caused rapid increases in streams and rivers, and flooding occurred as a result. 
Last year's high flows and flooding occurred around June 19th, which is a good reminder that there is still time for 
another precipitation event to push flows back up. Rivers and streams in the region have continued to run high since 
later May, so a close eye should be kept on the weather. 

This statement holds true in many rivers east of the Divide, which are reaching their seasonal peaks during the first week 
of June. Warm weather at the end of May caused significant melt rates at the high elevation locations, and rivers began 
to rise quickly after Memorial Day. Peak snowmelt drive flows this year will likely occur during the coming week or two, 
and the volumes for this year look to be above average for many locations. A significant rain event occurring while these 
rivers reach snowmelt-driven peaks could only amplify the flows. 

One concern this year is the rate at which snow has been melting, especially west of the Divide. The snowpack was 
below normal in many northern basins, but overall river volumes this year have been above average since March and 
peak flows were above average. This could translate to lower than average flows on non-controlled (naturally flowing, 
non-reservoir controlled) streams and rivers later in the summer. 

As always, summer weather will determine what ends up happening with regards to the overall volumes this water year. 
June is the last typically "wet" month in the state, before more convective weather patterns set in. Typically, June helps 
to provide some precipitation to provide additional water to the snowmelt runoff. Long-range outlooks for the month of 
June show equal chances of above or below average precipitation but indicate increased chances of temperatures being 
above average across the state. Given the how erratic and unpredictable weather patterns have been this water year 
(Oct 1 st - current), the best option might be to wait and see what happens. 





Kootenai River Basin 



It has been a dry winter and spring in the Kootenai River basin and the month of May followed suit. Typically, at this 
time of the year, only the high elevation snowpack monitoring sites are holding snow, and this year the snowpack at 
these elevations is well below normal. Early melt at many locations during April and May has resulted in a snowpack that 
is 48% of normal for June 1st. The high elevation Hawkins Lake SNOTEL site in the Yaak River basin, which typically has 
~40% of the annual peak snow water remaining, has melted out. This is two weeks earlier than normal for this site. 

Other high elevation sites in the region are also melting ahead of schedule this year but have 25% to 40% of this year's 
peak snowpack remaining. More notably, precipitation during May was well below average and the water year deficit 
continues to grow across the region. Monthly precipitation totals ranged from 17% to 75% of average at mountain 
SNOTEL sites, with basin-wide precipitation reported as 44% of average. Water-year precipitation for the basin dropped 
further this month and is 76% of average for June 1st. Early snowmelt and below normal snowpack for this date, coupled 
with below-average precipitation totals, means that surface water could be a concern later in the summer on non¬ 
reservoir-controlled streams in the region. 


Kootenai River Basin Data Summary 


Snowpack 

Percent of 1981-2010 
Normal (Median) 

Last Year Percentage of 
Normal (Median) 

KOOTENAY in CANADA 

71% 

49% 

KOOTENAI MAINSTEM 

48% 

139% 

TOBACCO 

58% 

109% 

FISHER 

% 

% 

YAAK 

0% 

0% 

KOOTENAI RIVER BASIN in MONTANA 

43% 

101% 

KOOTENAI ab BONNERS FERRY 

57% 

73% 

Basin-Wide Snowpack 

43% 

101% 


Precipitation 

Monthly Percentage of 
Average 

WYTD Percentage of 1981- 
2010 Average* 

WYTD Last Year 
Percentage of Average 

Mountain Precipitation 

44% 

76% 

109% 

Valley Precipitation 

% 

% 

% 

Basin-Wide Precipitation 

44% 

76% 

109% 


*WYTD Precipitation is October 1st- Current 


Reservoir Storage 

Percentage of Average 

Percentage of Capacity 
(Total) 

Last Year Percentage 
of Average 

Basin-Wide Reservoir Storage 

106% 

69% 

120% 


*See Reservoir Storage Table for storage in individual reservoirs 



Page 




































(click on chart below to navigate to online version with additional features) 


Snow Water Equivalent in 


KOOTENAI RIVER BASIN in MONTANA 

Jan Apr July WY 



Station List 

K Median Peak 5WE 
Max 

Median (POR) 
Median C'Sl-'lO) 

— Min 

Stats. Shading 
--2019 {3 sites) 

— 2013 (3 sites) 
- 2017 (3 sites) 

— 2016 (3 sites) 

- 2015 (3 sites) 

- 2014 (3 sites) 

-2013 {3 sites) 

— 2012 {3 sites) 

-2011 {3 sites) 

- 2010 {3 sites) 

— 2009 {3 sites) 

— 2008 {3 sites) 
- 2007 (3 sites) 



Statistical shading breaks al 10th r 30th r 50th, 70th, and 90th Percentiles. 


For more information visit: 30 year normals calculation description. 


Mountain and Valley 
Precipitation 

I Monthly ^^Year-to-date 



Oct Nov Dec Jan Feb Mar Apr May 


End of Month Reservoir 
Storage 

M% Capacity ■ Avg % Capacity 




ro 

CL 

ro 


U 


_QJ 

_Q 

m 

\/\ 





Oct Nov Dec Jan Feb Mar Apr May 


Storage above is averaged for all reservoirs in the 
basin. For individual reservoirs see table below. 


kO 



Page 































































Kootenai River Basin 
Snow Water Equivalent 
Percentage of Normal 
June 1, 2019 



Lake 

Minnewonka 


Airdrie 


Revel stoke 


■ankLake 


Nelson 


Femie- 


Montana 


Lake / 
McDonald 


Koocanilsa 


Whitefish 


Columbia Falls 


Lake 

Pend 

Oreille 


Ashley 

tleLake 


ilispell 58 Hungry 
W> Horse 
Bigfork Reservoir 

Lakeside 


rn~ 


Tran / ^^ \ ^ 

___CA 

WashirT«*' - '--CANADA 

asn,n 9ton ; . —- 

i Idaho 


Upper 


/ Priest 
Lake 


Priest 

Lake 


Snow Water Equivalent 
Percent of Normal 


SNOTEL Snowcourse 


• >150% 

© 

71 - 90% 

+ 

> 150% 

* 

71 - 90% 

• 131-150% 

• 

51 - 70% 

* 

131 -150% 

+ 

51 - 70% 

C 111-130% 

• 

1 - 50% 

* 

111 -130% 

+ 

1 - 50% 

$ 91 -110% 

* 

0% 

“S 3 

91 - 110% 

* 

0% 


Jispell 

«£ fa ' S * MONTANA 
j 'l ^Helena 
y Bozeman # •Billings 

C Boise 


r Boise _ 

f*IDAHO # 


Fi 'e'r'i fi'afi" 1 ® 11 "^STlTe 

WYOMING 

• Casp 1 


USDA 



eaojrce 
‘ Information System 


1^ 



Page 








































Kootenai River Basin 

Water Year to Date Precipitation and Reservoir Levels 
Percentage of Normal 
June 1, 2019 



Lake 

Minnewanka 


Airdrie 


rank Lake 


Keho L ike 


relson 


•Femie 


fasti egar 


CANADA 

Montana 


5- Lake , 
's McDonah 


1 Lake 
Koocanusa 


(Whitefisf 


Colum bia 


' Lake 
Pend 
Oreille 


Ashley 

Lake 


4 Evergreen 
[Kalispell 8 


Hungry 

Horse 

Reservoir 


Big fork 


Flathead 


—Canada \ 
in gton 




CANADA 


Idaho 


Upper 


Priest 


\ Lake 


i 


i Priest 


j Lake 


Precipitation 
Percent of Normal 
SNOTEL COOP/ACIS 


• > 150% 

• 131-150% 
O 111-130% 
% 91 - 110% 


0 71 - 90% 

• 51 - 70% 

• 1 - 50% 


# >150% 

0 131-150% 
0 111-130% 
0 91 - 110% 


® 

71 ■ 

- 90% 


51 • 

- 70% 

• 

1 ■ 

- 50% 


Reservoirs 
Percent of Normal 

■ > 150% 

j 131 - 150% 

□ 111-130% 

91 - 110% 

71 -90% 

51 -70% 

■ 1 - 50% 



USDA 



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. Resource 
f Information System 


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Page 






































Kootenai River Basin 

Monthly Precipitation and Reservoir Levels 
Percentage of Normal 
June 1,2019 (May 1, 2019 - June 1, 2019) 



CT) 


Page 











































Flathead River Basin 


The hope that May would deliver some moisture to the Flathead River basin, and help to offset the winter and spring 
deficits in snowfall and precipitation, was short lived this month. High elevation snowpack monitoring locations began 
their seasonal melt at the beginning of the month, and low mid elevations melted out during the first half of May. High 
elevation snowmelt is ahead of schedule this year (7 to 10 days), with 40% to 64% of this year's peak snowpack 
remaining. The impacts of this early melt will be felt later in the summer. More significant this month is the lack of 
precipitation during May. Monthly precipitation totals ranged from 31% to 56% in the northern two-thirds of the 
Flathead River basin, while the southern third received closer to average precipitation (65% to 98%). This north to south 
trend has played out throughout the winter and water year precipitation totals reflect this gradient. Northern locations 
are reporting 62% to 85% of average water-year precipitation (October 1st - current), while sites south of Flathead Lake 
are reporting 92% to 117% of average. The good news for local water users is that water managers have been keeping 
tabs on the below normal snowpack conditions throughout this winter. As a result, reservoir storage in Hungry Horse 
and Flathead Lake is near to above average for this time of year. Non-reservoir-controlled streams in the region will see 
drops in streamflows as the remaining high elevation snow melts, but the rate at which the rivers drop and how low 
they drop will be a function of summer precipitation and temperature. 


Flathead River Basin Data Summary 


Snowpack 

Percent of 1981-2010 
Normal (Median) 

Last Year Percentage of 
Normal (Median) 

NF FLATHEAD in CANADA 

0% 

0% 

NF FLATHEAD in MONTANA 

71% 

113% 

MIDDLE FORK FLATHEAD 

68% 

85% 

SOUTH FORK FLATHEAD 

58% 

115% 

STILL 1 A/A TER- WHITE FISH 

87% 

98% 

SWAN 

71% 

142% 

MISSION VALLEY 

78% 

114% 

LITTLE BITTERROOT-ASHLEY 

% 

% 

JOCKO 

80% 

172% 

FLATHEAD in MONTANA 

69% 

115% 

Basin-Wide Snowpack 

69% 

111% 


Precipitation 

Monthly Percentage of 
Average 

WYTD Percentage of 1981- 
2010 Average* 

WYTD Last Year 
Percentage of Average 

Mountain Precipitation 

59% 

87% 

122% 

Valley Precipitation 

54% 

104% 

105% 

Basin-Wide Precipitation 

58% 

88% 

121% 


*Water Year-to-Date (WYTD) Precipitation is October 1st - Current 


Reservoir Storage 

Percentage of Average 

Percentage of Capacity 
(Total) 

Last Year Percentage 
of Average 

Basin-Wide Reservoir Storage 

109% 

89% 

111% 


o 

CNJ 


*See Reservoir Storage Table for storage in individual reservoirs 


Page 







































(click on chart below to navigate to online version with additional features) 


Snow Water Equivalent in 
FLATHEAD RIVER BASIN 


Jan Apr July WY 



* Median Peak 5WE 
— Max 

Median (POR) 
Median C'Sl-'lO) 

— Min 

Stats. Shading 

-- 2019 (12 sites) 

- 20IB {11 sites) 

-- 2017 {12 sites) 

— 2016 {12 sites) 

- 2015 (12 sites) 

- 2014 {12 sites) 

-— 2013 {12 sites) 
■— 2012 {12 sites) 

— 2011 {12 sites) 

- 2010 {12 sites) 

■-- 2009 {12 sites) 

— 200B {12 sites) 

- 20 0 7 {12 sites) 


Statistical shading breaks at 10th, 30th r 50th, 7tJth, and 90th Percentiles. 
For mere information visit: 30 year normals calculation description. 


Mountain and Valley 
Precipitation 


I Monthly 


■Year-to-date 



80 

60 

40 

20 

0 





End of Month Reservoir 
Storage 


I % Capacity 


Avg % Capacity 



Oct Nov Dec Jan Feb Mar Apr May 


Oct Nov Dec Jan Feb Mar Apr May 


^—I 

CM 


Storage above is averaged for all reservoirs in the 
basin. For individual reservoirs see table below. 


Page 















































Flathead River Basin 
Snow Water Equivalent 
Percentage of Normal 
June 1, 2019 



St Mary's 
1 eservoir 


CANADA 

Montana 


Lake 

Koocanusa 


Lake^*/ 

McDonald, 




•Whitefish 


Iblumbia Falls 


Ashler 

Lake 


Evergreen 


Bigfork 


Noxon 

\eservoir 


Flathead 

Lake 


Choteai 


Polsor 


Thompson Falls 


Pablo 


'Ronan 


Snow Water Equivalent 
Percent of Normal 


SNOTEL Snowcourse 


• 

> 150% 

© 

71 - 90% 

+ 

> 150% 

* 

71 - 90% 

• 

131 -150% 

• 

51 - 70% 

* 

131 -150% 

+ 

51 - 70% 

c 

111 -130% 

• 

1 - 50% 

* 

111 -130% 

+ 

1 - 50% 

• 

91 -110% 

* 

0% 

“S 3 

91 - 110% 

* 

0% 


flatus. MONTANA 


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Page 
































Flathead River Basin 

Water Year to Date Precipitation and Reservoir Levels 
Percentage of Normal 
June 1, 2019 



S. Mary's 
I eservoir 


CANADA 

Montana 


Lake { 
McDonatas 


fnaisp. 


(Whitefish 


Columl ia Ffells 


Kalisp^ 


\ake 


•Big fork 

Flathead\ 
Lake \ 


ioxon 


Choteau 


lompson Falls 


Pablo< 


>Ronan 


Seeley Lake 


Lake 

Koocanusa 


Cut Bank 


Precipitation 
Percent of Normal 
SNOTEL COOP/ACIS 


• > 150% 

• 131-150% 
O 111-130% 

C 91 - 110% 


o 

71 

- 90% 

• 

51 

- 70% 

• 

1 

- 50% 


# >150% 

0 131-150% 
0 111-130% 
0 91 - 110% 


® 

71 

- 90% 


51 

- 70% 

• 

1 

- 50% 


Reservoirs 
Percent of Normal 


■ 

> 150% 

□ 

131 

- 150% 

□ 

111 

- 130% 

□ 

91 

- 110% 

□ 

71 

- 90% 

■ 

51 

- 70% 

■ 

1 

- 50% 



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lL i ★Helena 
Bozeman # •Billings 


Gillette 


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Page 




























Flathead River Basin 

Monthly Precipitation and Reservoir Levels 
Percentage of Normal 
June 1, 2019 (May 1, 2019 - June 1, 2019) 



rsi 


Page 
























Upper Clark Fork River Basin 



Most low and mid-elevations melted out during the month of May in the Upper Clark Fork River basins, causing rivers to 
rise across the region. Snowmelt driven peak flows (flows driven only by snowmelt) likely occurred on many rivers 
during the third week of the month, but rivers have remained high through the end of the month. Snowpack on June 1st 
remains at the high elevations in the basin, which will help to sustain flows over the coming month, is slightly below 
normal for the basin overall, but above normal in some of the sub-basins in the headwaters of the Clark Fork. 
Precipitation during May was variable, with some sites reporting well below average precipitation, while others reported 
above average precipitation. This was likely due to the convective nature of storms this spring (thunderstorms and not 
large fronts). June is the last “wet” month in the region before more typical summer weather patterns play out and will 
play an important role in the flows later in the summer months. 


Upper Clark Fork River Basin Data Summary 


Snowpack 

CLARK FORK ab FLINT CREEK 

FLINT CREEK 

ROCK CREEK 

CLARK FORK ab BLACKFOOT 

BLACKFOOT 

Percent of 1981-2010 
Normal (Median) 

Last Year Percentage of 
Normal (Median) 

114% 

131% 

107% 

0% 

46% 

62% 

102% 

117% 

83% 

169% 

Basin-Wide Snowpack 

93% 

140% 


Precipitation 

Monthly Percentage of 
Average 

WYTD Percentage of 1981- 
2010 Average* 

WYTD Last Year 
Percentage of Average 

Mountain Precipitation 

89% 

98% 

128% 

Valley Precipitation 

122% 

116% 

119% 

Basin-Wide Precipitation 

90% 

99% 

128% 


*Water Year-to-Date (WYTD) Precipitation is October 1st - Current 


Reservoir Storage 

Percentage of Average 

Percentage of Capacity 
(Total) 

Last Year Percentage of 
Average 

Basin-Wide Storage 

108% 

93% 

118% 


*See Reservoir Storage Table for storage in individual reservoirs 


LD 

C\J 


Page 


































of Average 


(click on chart below to navigate to online version with additional features) 


Snow Water Equivalent in 


CLARK FORK RIVER BASIN 

Jan Apr July WY 


o 

c 

U) 


Nov 1 Jan 1 Mar 1 May 1 Jul 1 



30 


j>NRC$ 

Current as of 06/03/Z019: 

% of Median - 94^ 

% Median Peak - 2B% 

Days Since Median Peak - 57 
Percentile - 41 




Station List 

K Median Peak SWE 
Max 

Median (POR) 
Median ['Sl-'iO) 

— Min 

Stats. Shading 
■-2019 (19 sites) 

— 20IS (19 sites) 

— 2017 (19 sites) 

—— 2016 (19 sites) 

— 2015 (19 sites) 

- 2014 (19 sites) 

-—- 2013 (19 sites) 

— 2012 (19 sites) 
- 2011 (19 sites) 

— 2010 (19 sites) 
- 2009 (19 sites) 

— 20OS (19 sites) 
2007 ( 19 sites) 



Statistical shading breaks at 10th r 30th r 50th, 70th, and 90th Percentiles, 


For more information visit: 30 year normals calculation description. 


Mountain and Valiev 
Precipitation 


Monthly 


•Year-to-date 


200 

180 

160 

140 

120 

100 

80 

60 

40 

20 

0 



is n 


I! 

mi 


mum 


11111111 


■hhi 


Oct Nov Dec Jan Feb Mar Apr May 


End of Month Reservoir 
Storage 

■ % Capacity ■ Avg % Capacity 


l u 


ro 

□_ 

ro 


U 


ju 

_Q 

ro 

D 





Oct Nov Dec Jan Feb Mar Apr May 


Storage above is averaged for all reservoirs in the 
basin. For individual reservoirs see table below. 


kO 

CNl 


Page 











































Upper Clark Fork River Basin 
Snow Water Equivalent 
Percentage of Normal 
June 1, 2019 



# 91 - 110 % 0 % 


91 - 110 % * 0 % 


USDA 


eaojrce 
‘ Information System 


Csj 


Page 























Upper Clark Fork River Basin 
Water Year to Date Precipitation and Reservoir Levels 
Percentage of Normal 
June 1, 2019 



Precipitation 
Percent of Normal 
SNOTEL COOP/ACIS 


• > 150% 

• 131-150% 
O 111-130% 
% 91 - 110% 


0 71 - 90% 

• 51 - 70% 

• 1 - 50% 


# >150% 

0 131-150% 
0 111-130% 
0 91 - 110% 


® 

71 ■ 

- 90% 


51 • 

- 70% 

• 

1 ■ 

- 50% 


Reservoirs 
Percent of Normal 


■ 

> 150% 

□ 

131 

- 150% 

□ 

111 

- 130% 

□ 

91 

- 110% 

□ 

71 

- 90% 

■ 

51 

- 70% 

■ 

1 

- 50% 



USDA 



iteUbwy 

. Resource 
f Information System 


OO 

Csj 


Page 















Upper Clark Fork River Basin 
Monthly Precipitation and Reservoir Levels 
Percentage of Normal 
June 1,2019 (May 1, 2019 - June 1, 2019) 



Precipitation 
Percent of Normal 


SNOTEL 

• > 150% 

• 131-150% 

O 111-130% 
% 91 - 110% 


o 

71 

- 90% 

• 

51 

- 70% 

• 

1 

- 50% 


COOP/ACIS 

+ >150% 

0 131-150% 
0 111-130% 
0 91 - 110% 


® 

71 

- 90% 


51 

- 70% 

• 

1 

- 50% 


Reservoirs 
Percent of Normal 


■ 

> 150% 


131 

- 150% 

□ 

111 

- 130% 

□ 

91 

- 110% 

□ 

71 

- 90% 

□ 

51 

- 70% 

■ 

1 ■ 

- 50% 



CT) 

C\J 


Page 



















Bitterroot River Basin 



What's left to say about snowpack and snowmelt in the river basin on June 1st? Compared to last year, it's kind of 
boring. Snowmelt has been right on schedule this year, if not a little ahead of schedule at high elevations. What was 
interesting this month was the below average precipitation for May. The month started out slowly with little 
precipitation falling during the first two weeks of the month. Fortunately, a few storms that pushed through towards the 
end of the month delivered 2 to 3" of moisture before the month ended. Overall water year precipitation (October 1st - 
current) remains near average for most mountain locations in the basin. Looking forward, the remaining high elevation 
snowpack will melt, and the river volumes will drop from their snowmelt-driven levels. Summer flows will be driven by 
how fast the remaining snow melts, and how much summer precipitation falls, so hope for a cool and wet June to keep 
water in the rivers and streams later in the summer. 


Bitterroot River Basin Data Summary 


Snowpack 

Percent of 1981-2010 
Normal (Median) 

Last Year Percentage of 
Normal (Median) 

WEST FORK BITTERROOT 

102% 

128% 

EAST SIDE BITTERROOT 

82% 

104% 

WEST SIDE BITTERROOT 

64% 

127% 

Basin-Wide Snowpack 

74% 

113% 


Precipitation 

Mountain Precipitation 

Valley Precipitation 

Monthly Percentage of 
Average 

WYTD Percentage of 1981- 
2010 Average* 

WYTD Last Year 
Percentage of Average 

67% 

99% 

118% 

% 

% 

% 

Basin-Wide Precipitation 

67% 

99% 

118% 


*Water Year-to-Date (WYTD) Precipitation is October 1st - Current 



Percentage of Average 

Percentage of Capacity 
(Total) 

Last Year Percentage of 
Average 

Basin-Wide Storage 

108% 

106% 

108% 


o 

CD 


*See Reservoir Storage Table for storage in individual reservoirs 


Page 
































(click on chart below to navigate to online version with additional features) 


Snow Water Equivalent in 


BITTERROOT RIVER BASIN 

Jan Apr July WY 



Station List 

It Median Peak 5WE 
Max 

Median (PGR) 
Median ['Bl-TO) 

- Min 

Stats, Shading 

■-2019 (7 sites) 

-- 2013 {7 sites) 

— 2017 {7 sites) 
2016 (7 sites) 

— 2015 (7 sites) 

— 2014 (7 sites) 

- 2013 {7 sites) 

-- 2012 {7 sites) 

-- 2011 (7 sites) 

-- 2010 (7 sites) 

-- 2009 (7 sites) 

— 2003 (7 sites) 

1 - 2007 {7 sites) 



Statistical shading breaks al 10th r 30th r 50th, 70th, and 90th Percentiles. 


For more information visit: 30 year normals calculation description. 


Mountain and Valley 
Precipitation 

Monthly Ye ar -to - d ate 

200 
180 
160 

oj 140 

CJD 

rc 

gj 120 

< 

o 100 
80 
60 
40 
20 
0 

Oct Nov Dec Jan Feb Mar Apr May 



End of Month Reservoir 
Storage 

M% Capacity ■ Avg % Capacity 


100 


•? BO 

rt5 

CL 


_QJ 

-s BO 

in 


40 


20 


0 


Storage above is averaged for all reservoirs in the 
basin. For individual reservoirs see table below. 



Oct Nov Dec Jan Feb Mar Apr May 


^—I 
CD 


Page 








































Bitterroot River Basin 
Snow Water Equivalent 
Percentage of Normal 
June 1, 2019 



CM 

CO 


Page 


















Bitterroot River Basin 

Water Year to Date Precipitation and Reservoir Levels 
Percentage of Normal 
June 1, 2019 



Precipitation 
Percent of Normal 


SNOTEL 

• > 150% 

• 131-150% 

O 111-130% 
% 91 - 110% 


0 71 - 90% 

• 51 - 70% 

• 1 - 50% 


COOP/ACIS 

+ >150% 

0 131-150% 
0 111-130% 
0 91 - 110% 




71 - 90% 
51 - 70% 
1 - 50% 


Reservoirs 
Percent of Normal 


■ 

> 150% 

□ 

131 

- 150% 

□ 

111 

- 130% 

□ 

91 

- 110% 

□ 

71 

- 90% 

■ 

51 

- 70% 

■ 

1 

- 50% 



USDA 



iteUbwy 

. Resource 
f Information System 


m 

ro 


Page 












Bitterroot River Basin 

Monthly Precipitation and Reservoir Levels 
Percentage of Normal 
June 1, 2019 (May 1, 2019 - June 1, 2019) 



ro 


Page 













Lower Clark Fork River Basin 


Only three sites in the Lower Clark Fork River basin have snowpack remaining on June 1st. These high elevation sites 
benefitted from the cooler weather during the middle of the month, which helped to slow melt that was occurring at 
during the first two weeks of the month and helped to sustain the snowpack into June. The month of May yielded 
below-average precipitation across the basin with most of the precipitation falling during the last two weeks of the 
month. Although both March and May were disappointing for precipitation, water year precipitation totals (October 1st) 
are hovering near to slightly above average in the upper basin (near Missoula), but decline to below normal as you move 
down the basin toward the Idaho border. Rivers began their seasonal rise in April but made their big snowmelt drives 
pushes during the month of May. Seasonal snowmelt-driven river peaks likely occurred during the third week of May, 
and rivers have been on the slow decline since. 


Lower Clark For River Basin Data Summary 


Snowpack 

LOWER CLARK FORK RIVER BASIN 

Percent of 1981-2010 
Normal (Median) 

Last Year Percentage of 
Normal (Median) 

92% 

148% 

Basin-Wide 

92% 

148% 


Precipitation 

Mountain Precipitation 

Valley Precipitation 

Monthly Percentage of 
Average 

WYTD Percentage of 
1981-2010 Average* 

WYTD Last Year 
Percentage of Average 

76% 

90% 

114% 

90% 

144% 

134% 

Basin-Wide Precipitation 

77% 

92% 

114% 


*Water Year-to-Date (WYTD) Precipitation is October 1st - Current 


Reservoir Storage 

Percentage of Average 

Percentage of Capacity 
(Total) 

Last Year Percentage 
of Average 

Basin-Wide Storage 

102% 

98% 

102% 


*See Reservoir Storage Table for storage in individual reservoirs 


LD 

ro 


Page 






























(click on chart below to navigate to online version with additional features) 


Station List 

K Median Peak 5WE 
— Max 

Median (POR) 
Median ['Bl-'IO) 
—* Mir 

Stats, Shading 

-- 2019 (7 sites) 

-2013 (7 sites) 

— 2017 (7 sites) 
- 2016 (7 sites) 

— 2015 (7 sites) 
- 2014 {7 sites) 

— 2013 {7 sites) 

-2012 (7 sites) 

-- 2011 (7 sites) 

-—- 2010 {7 sites) 

-- 2009 (7 sites) 

-* 2003 (7 sites) 

- 2007 (7 sites) 

■ 

Statistical shading breaks at lQth r 30th r 50th, 70th, and 90th Percentiles. 

For more information visit: 30 year normals calculation description. 


Mountain and Valley End of Month Reservoir 

Precipitation Storage 



Oct Nov Dec Jan Feb Mar Apr May Oct Nov Dec Jan Feb Mar Apr May 


Storage above is averaged for all reservoirs in the 
basin. For individual reservoirs see table below. 



Snow Water Equivalent in 
LOWER CLARK FORK RIVER BASIN 

Jan Apr July WY 



Nov 1 Jan 1 Mar 1 May 1 Jul 1 


kO 

ro 


Page 






















































Lower Clark Fork River Basin 
Snow Water Equivalent 
Percentage of Normal 
June 1, 2019 



Lake 

McDonald 


Lake 

Koocanusa 


•Whitefish 


Ashley 

Lake 


^Evergreen 

Kalispell 


little 

Bitterroot 


Xox\ 

Reserbo, 


Thompson Falls 


Pablo« 


Ronan 


umbia Falls 

Hungry 

Horse 

Reservoir 


Big fork 


Flathead 

Lake 


*tnt Jo 


4V v cT 






Dworshak 

Reservoir 


Snow Water Equivalent 
Percent of Normal 


SNOTEL Snowcourse 


• 

> 150% 

© 

71 - 90% 

+ 

> 150% 

* 

71 - 90% 

• 

131 -150% 

• 

51 - 70% 

* 

131 -150% 

+ 

51 - 70% 

c 

111 -130% 

• 

1 - 50% 

* 

111 -130% 

+ 

1 - 50% 

• 

91 -110% 

* 

0% 

“S 3 

91 - 110% 

* 

0% 


Og Ms « MONTANA 

J ^Helena 

J Bozeman « • Billings 

f Boise 

h - 


r Boise _ 

f*IDAHO # 


'CTiTette 

WYOMING 

• Casp* 


USDA 



eaojrce 
‘ Information System 


CO 


Page 
















Lower Clark Fork River Basin 
Water Year to Date Precipitation and Reservoir Levels 
Percentage of Normal 
June 1, 2019 



Lake 

Koocanusa 

106 


Whitefish 


:olumbia Falls 


Ashley 

Lake 


'Kalispell 


little 

[erroot 


lompson Falls 


Pablo* 


Ronan 


92 

115 ® 

Hungry 

Horse 

Reservoir 


Big fork* 


Flathead 

Lake 


s <nntJc^ 


-fiver 


*■ 


Joe 


Dworshak 

Reservoir 


' vp Mt 


Precipitation 
Percent of Normal 
SNOTEL COOP/ACIS 


• > 150% 

• 131-150% 

O 111-130% 
% 91 - 110% 


o 

71 

- 90% 

• 

51 

- 70% 

• 

1 

- 50% 


# >150% 

0 131-150% 
0 111-130% 
0 91 - 110% 


® 

71 ■ 

- 90% 


51 • 

- 70% 

• 

1 ■ 

- 50% 


Reservoirs 
Percent of Normal 


■ 

> 150% 

□ 

131 

- 150% 

□ 

111 

- 130% 

□ 

91 

- 110% 

□ 

71 

- 90% 

■ 

51 

- 70% 

■ 

1 

- 50% 



USDA 



iteUbwy 

. Resource 
f Information System 


00 

ro 


Page 













Lower Clark Fork River Basin 
Monthly Precipitation and Reservoir Levels 
Percentage of Normal 
June 1, 2019 (May 1, 2019 - June 1, 2019) 



CT) 

ro 


Page 















Jefferson River Basin 



May yielded variable precipitation to the Jefferson Drainage as the Ruby received just a third of its average while the 
Bighole, Beaverhead, and Boulder were only slightly below normal. The good news is water year to date numbers are 
spot on at 101% of average and snowpack in the Ruby is 128% of normal while the basin-wide average is near normal. 
Reservoir storage is up to 119% of average as water managers are trying to hold back as much as they can with an 
average snowpack above them in the mountains. Water supplies are looking sufficient for now, but keep in mind that 
we still need to receive normal amounts of precipitation from June to August to avoid water shortages towards the end 
of the irrigation season. 


Jefferson River Basin Data Summary 


Snowpack 

Percent of 1981-2010 
Normal (Median) 

Last Year Percentage of 
Normal (Median) 

BEAVERHEAD 

119% 

94% 

RUBY 

128% 

90% 

BIGHOLE 

101% 

113% 

BOULDER 

116% 

124% 

Basin-Wide Snowpack 

102% 

120% 


Precipitation 

Monthly Percentage of 
Average 

WYTD Percentage of 1981- 
2010 Average* 

WYTD Last Year 
Percentage of Average 

Mountain Precipitation 

86% 

101% 

112% 

Valley Precipitation 

% 

% 

% 

Basin-Wide Precipitation 

86% 

101% 

112% 


*Water Year-to-Date (WYTD) Precipitation is October 1st - Current 


Reservoir Storage 

Percentage of Average 

Percentage of Capacity 
(Total) 

Last Year Percentage of 
Average 

Basin-Wide Storage 

116% 

72% 

127% 


*See Reservoir Storage Table for storage in individual reservoirs 


o 


Page 1 


































(click on chart below to navigate to online version with additional features) 


Snow Water Equivalent in 


JEFFERSON RIVER BASIN 

Jan Apr July WY 



Nov 1 Jan 1 Mar 1 May 1 Jul 1 


Station List 

U Median Peak 5WE 
Max 

Median (POR) 
Median ('81-10) 

— Min 

Stats. Shading 
-2019 (19 sites) 

— 2018 (19 sites) 

-- 2017 (19 sites) 

■—- 2016 (19 sites) 

— 2015 (19 sites) 

-- 2014 (19 sites) 

— 2013 (19 sites) 

- - 2012 (19 sites) 

— 2011 (19 sites) 

-- 2010 (19 sites) 

— 2009 (19 sites) 

— 2008 (19 sites) 
- 2007 (19 sites) 



Statistical shading breaks at 10th r 30th r 50th, 70th, and 90th Percentiles. 


For more information visit: 30 year normals calculation description. 


Mountain and Valley 
Precipitation 

^M M o n th ly ^^Ye ar -to - d ate 

200 
180 
160 
o WO 

tn 
ro 

gj 120 

< 

° 100 
80 
60 
40 
20 
0 

Oct Nov Dec Jan Feb Mar Apr May 





Mini 




End of Month Reservoir 
Storage 

■ % Capacity ■ Avg % Capacity 


1 1 U - 

inn _ 


i u u - 

qn _ 


■J u - 

-S’ qn _ 


L U 

CD 

Cl 

m 7n _ 

u 

(J 

OJ 

_q cn _ 

Ml 1 

fln 

#1 1 

min 

min i 

i 

i m m 11 


Oct Nov Dec Jan Feb Mar Apr May 


Storage above is averaged for all reservoirs in the 
basin. For individual reservoirs see table below. 


^—I 


Page 1 





































Jefferson River Basin 
Snow Water Equivalent 
Percentage of Normal 
June 1, 2019 



SNOTEL 


Snow Water Equivalent 
Percent of Normal 

Snowcourse 


• 

> 150% 

© 

71 - 90% 

+ 

> 150% 

* 

71 - 90% 

• 

131 -150% 

• 

51 - 70% 

* 

131 -150% 

+ 

51 - 70% 

G 

111 -130% 

• 

1 - 50% 

* 

111 -130% 

+ 

1 - 50% 

• 

91 -110% 

* 

0% 


91 - 110% 

* 

0% 


wanspen 

F Isreat Falls* 

.1 i i— r*/ ilTI o 

MONTANA 


J T ^Helena 

J ^ozerrtarr* • Billings 


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CD 

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03 

Cl 
























Jefferson River Basin 

Water Year to Date Precipitation and Reservoir Levels 
Percentage of Normal 
June 1, 2019 



Mou 1 i ( ? r ■ 


Anaconda 


Three Foi 


lanhattar 




Dillon 


Canmn 

Reser\ir 


Henrys 

Lake 


Park 

Reservoiri 


Hamilton 


180 




::s 


Lake 




138 


E ig Sky Memow Village 


Hebgen 

Lake 


Precipitation 
Percent of Normal 


SNOTEL 

• > 150% 

• 131-150% 

O 111-130% 
% 91 - 110% 


o 

71 

- 90% 

• 

51 

- 70% 

• 

1 

- 50% 


COOP/ACIS 

+ >150% 

0 131-150% 
0 111-130% 
0 91 - 110% 




71 - 90% 
51 - 70% 
1 - 50% 


Reservoirs 
Percent of Normal 


■ 

> 150% 

□ 

131 

- 150% 

□ 

111 

- 130% 

□ 

91 

- 110% 

□ 

71 

- 90% 

■ 

51 

- 70% 

■ 

1 

- 50% 



USDA 



iteUbwy 

. Resource 
f Information System 


no 


Page 1 


















Jefferson River Basin 

Monthly Precipitation and Reservoir Levels 
Percentage of Normal 
June 1,2019 (May 1, 2019 - June 1, 2019) 



Bo u \i?r- 


Anaconda 


err 00 stiver 


•Dillon 


Upper 

Red< 

' Lake ir_ 


T voir 


Henrxs 


•V 


Lake 


Island, 

Park 

Reservoir 


84 

101 

Ennis 

Lake 

69 


Precipitation 
Percent of Normal 


SNOTEL 


COOP/ACIS 


• > 150% 

• 131-150% 
O 111-130% 
% 91 - 110% 


0 71 - 90% 

• 51 - 70% 

• 1 - 50% 


# >150% 

0 131-150% 
0 111-130% 
0 91 - 110% 


® 

71 ■ 

- 90% 


51 ■ 

- 70% 

• 

1 ■ 

- 50% 


Reservoirs 
Percent of Normal 


■ 

> 150% 


131 

- 150% 

□ 

111 

- 130% 

□ 

91 

- 110% 

□ 

71 

- 90% 

□ 

51 

- 70% 

■ 

1 ■ 

- 50% 





Page 1 






















Madison River Basin 



The Madison still holds 138% of normal snowpack as of June 1 st , which has been slowly melting off over the month of 
May. All of the Madison Plateau sites reached their peak snowpack in late April, while the Gravellys, Tobacco Roots and 
northern Madisons peaked in early May. Precipitation was also near normal for the month of May, which is a first for 
this winter, as we have been see-sawing back and forth from record breaking dry spells, to record accumulation. 
Amazingly, as of June, the Madison has pulled through with well above average snowpack. There's still 173% of normal 
snowpack above Hebgen Lake which is starting to enter the streams, while Hebgen is already at 84% of capacity. The 
first surge of melt came in mid-May, bumping the Madison River above Hebgen to 3000 CFS and now we are seeing the 
higher elevation snowpack enter the system, of which reservoir managers are only passing half of the inflow. Above 
normal snowpack, above average water-year precipitation, and excellent reservoir storage for this date should ensure 
adequate water supply in the Madison River this summer. 


Madison River Basin Data Summary 


Snowpack 

MADISON abv HEBGEN LAKE 

MADISON blw HEBGEN LAKE 

Percent of 1981-2010 
Normal (Median) 

Last Year Percentage of 
Normal (Median) 

173% 

126% 

124% 

86% 

Basin-Wide Snowpack 

138% 

98% 


Precipitation 

Mountain Precipitation 

Valley Precipitation 

Monthly Percentage of 
Average 

WYTD Percentage of 1981- 
2010 Average* 

WYTD Last Year 
Percentage of Average 

87% 

108% 

110% 

78% 

162% 

152% 

Basin-Wide Precipitation 

86% 

111% 

113% 


*Water Year-to-Date (WYTD) Precipitation is October 1st - Current 


Reservoir Storage 

Percentage of Average 

Percentage of Capacity 
(Total) 

Last Year Percentage of 
Average 

Basin-Wide Storage 

95% 

84% 

105% 


*See Reservoir Storage Table for storage in individual reservoirs 


LD 


Page 1 

































(click on chart below to navigate to online version with additional features) 


Snow Water Equivalent in 


MADISON RIVER BASIN 

Jan Apr July WY 



Station List 

K Median Peak SWE 
Max 

Median (POR) 
Median C'Bl-’lO) 

.—. Min 

Stats. Shading 

■-- 2019 (11 sites) 

-- 2018 (11 sites) 

-2017 (11 sites) 

-- 2016 (11 sites) 

- 2015 (11 sites) 

— 2014 (11 sites) 

- 2013 (11 sites) 

--- 2012 (11 sites) 

— 2011 (11 sites) 

- 2010 (11 sites) 

- - 2009 (11 sites) 

- 2008 (11 sites) 

-- 2007 (11 sites) 



Statistical shading breaks at 10th r 30th r 50th, 70th, and 90th Percentiles. 


For more information visit: 30 year normals calculation description. 


Mountain and Valley 
Precipitation 

M o n th ly V e ar -to - d ate 



Oct Nov Dec Jan Feb Mar Apr May 


End of Month Reservoir 
Storage 

■ % Capacity ■ Avg % Capacity 



Oct Nov Dec Jan Feb Mar Apr May 


Storage above is averaged for all reservoirs in the 
basin. For individual reservoirs see table below. 


to 


Page 1 





























































Madison River Basin 
Snow Water Equivalent 
Percentage of Normal 
June 1, 2019 



Three /oj 


Bozem; 


Livingston 


Big Skwtfleadow Village 


Montana 

Wyoming 


^/litin 4 ^ 


Yellowstone 


Henrys 

Lake 




152 


Lima 

Reservoir 


Upper 

Red 

Rock 

Lake 


284 


Yellowstone 

Lake 


Island 
Park j 
Reservoir) 20 


Snow Water Equivalent 
Percent of Normal 


SNOTEL Snowcourse 


• 

> 150% 

G 

71 - 90% 

+ 

> 150% 

* 

71 - 90% 

• 

131 -150% 

• 

51 - 70% 

* 

131 -150% 

+ 

51 - 70% 

C- 

111 -130% 

• 

1 - 50% 

* 

111 -130% 

+ 

1 - 50% 

• 

91 -110% 

* 

0% 

* 

91 - 110% 

* 

0% 


pfispeiP 

breat Falls # MONTANA 
y ^Helena 
E&zernan* • Billings 




USDA 



eaojrce 
‘ Information System 




Page 1 
























Madison River Basin 

Water Year to Date Precipitation and Reservoir Levels 
Percentage of Normal 
June 1, 2019 



Forks 


Bozemi 


Livingston 


Big SkyJweadow Village 


'el lows t< 


Henry's 

Lake 


Jf 


114 


• 105 


106 


105 


Montana 

Wyoming 

121 




Upper 

Red. 

91 • ££ 


Lima 

Reservoir 


Yellowstone 

Lake 


IslancbC. jfc] 

Park 

Reservoir/ 20 


Precipitation 
Percent of Normal 
SNOTEL COOP/ACIS 


• > 150% 

• 131-150% 
O 111-130% 

C 91 - 110% 


0 71 - 90% 

• 51 - 70% 

• 1 - 50% 


# >150% 

0 131-150% 
0 111-130% 
0 91 - 110% 


® 

71 ■ 

- 90% 


51 • 

- 70% 

• 

1 ■ 

- 50% 


Reservoirs 
Percent of Normal 


■ 

> 150% 

□ 

131 

- 150% 

□ 

111 

- 130% 

□ 

91 

- 110% 

□ 

71 

- 90% 

■ 

51 

- 70% 

■ 

1 

- 50% 



oo 


Page 1 























Madison River Basin 

Monthly Precipitation and Reservoir Levels 
Percentage of Normal 
June 1, 2019 (May 1, 2019 - June 1, 2019) 



O') 


Page 1 





















Gallatin River Basin 



High elevation sites in the Gallatin basin reached their peak snowpack in the first week of May and have been slowly 
melting over the last three weeks with 140% of normal snowpack remaining. Thankfully, these snow water stores are 
making up for lack luster May precipitation, as only the Bridgers received near normal amounts. Nonetheless, Middle 
Creek Reservoir is topping up with over 10,000 acre-feet, and water users that use water from Middle Creek should have 
adequate water for irrigation and municipal water supply. The Gallatin is making it's big seasonal push for snowmelt- 
driven flows and has been rapidly rising during the first week of June due to the well above average temperatures that 
have persisted since Memorial Day. Cool weather forecasted should help to slow the melt of the remaining snowpack. 

As mentioned last month, May and June are historically big precipitation months, and we still need June to come 
through to supplement the snowmelt and help keep water in the river and streams later in the summer. 


Gallatin River Basin Data Summary 


Snowpack 

Percent of 1981-2010 
Normal (Median) 

Last Year Percentage of 
Normal (Median) 

UPPER GALLATIN 

126% 

86% 

HYALITE 

118% 

125% 

BRIDGER 

432% 

87% 

Basin-Wide Snowpack 

140% 

98% 


Precipitation 

Mountain Precipitation 

Valley Precipitation 

Monthly Percentage of 
Average 

WYTD Percentage of 1981- 
2010 Average* 

WYTD Last Year 
Percentage of Average 

77% 

113% 

121% 

60% 

111% 

129% 

Basin-Wide Precipitation 

74% 

113% 

122% 


*Water Year-to-Date (WYTD) Precipitation is October 1st - Current 


Reservoir Storage 

Percentage of Average 

Percentage of Capacity 
(Total) 

Last Year Percentage of 
Average 

Basin-Wide Storage 

120% 

101% 

120% 


*See Reservoir Storage Table for storage in individual reservoirs 


o 

LO 


Page 

































(click on chart below to navigate to online version with additional features) 


Snow Water Equivalent in 


GALLATIN RIVER BASIN 

Jan Apr July WY 


D 

CT 

LU 


C 

U) 


Nov 1 Jan 1 Mar 1 May 1 Jul 1 



Station List 

K Median Peak SWE 

— Max 

Median (POR) 
Median ('ei-'lO] 

— Min 

Stats. Shading 

-2019 (7 sites) 

—- 2018 (7 sites) 

— 2017 (7 sites) 

— 2016 (7 sites) 

- 2015 (7 sites) 

-—- 2014 {7 sites) 

- 2013 (7 sites) 

-- 2012 (7 sites) 

— 2011 (7 sites) 

■-- 2010 {7 sites) 

— 2009 (7 sites) 

— 2003 (7 sites) 
j — 2007 {7 sites) 



Statistical shading breaks at 10th r 30th r 50th, 70th, and 9Oth Percentiles. 


For more information visit: 30 year normals calculation description. 


Mountain and Valley 
Precipitation 


Monthly 


■Vear-to-date 



m 

mi 


mini 


11111111 i 


Oct Nov Dec Jan Feb Mar Apr May 


End of Month Reservoir 
Storage 

■ % Capacity ■ Avg % Capacity 



Oct Nov Dec Jan Feb Mar Apr May 


^—I 

LO 


Storage above is averaged for all reservoirs in the 
basin. For individual reservoirs see table below. 


Page 































































Gallatin River Basin 
Snow Water Equivalent 
Percentage of Normal 
June 1, 2019 



Snow Water Equivalent 
Percent of Normal 


SNOTEL 


• 

> 150% 

© 

71 - 90% 

• 

131 -150% 

• 

51 - 70% 

c 

111 -130% 

• 

1 - 50% 

• 

91 -110% 

* 

0% 


Snowcourse 


+ 

> 150% 

* 

71 - 90% 

* 

131 -150% 

+ 

51 - 70% 

* 

111 -130% 

+ 

1 - 50% 

* 

91 - 110% 

* 

0% 


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■real Falls. MONTANA 


**?* ^Helena 

—- —■ - Billings 


j r *•- 

» Bozeman^l 

{ Boise 

[★IDAHO. 


WYOMI 



USDA 


CM 

LO 


Page 




























Gallatin River Basin 

Water Year to Date Precipitation and Reservoir Levels 
Percentage of Normal 
June 1, 2019 



Precipitation 
Percent of Normal 


SNOTEL 

• > 150 % 

• 131 - 150 % 

O 111 - 130 % 
® 91 - 110 % 


o 

71 - 90% 

• 

51 - 70% 

• 

1 - 50% 


COOP/ACIS 

+ > 150 % 

0 131 - 150 % 
0 111 - 130 % 
0 91 - 110 % 




71 - 90 % 
51 - 70 % 
1 - 50 % 


Reservoirs 
Percent of Normal 


■ 

> 150 % 

□ 

131 

- 150 % 

□ 

111 

- 130 % 

□ 

91 

- 110 % 

□ 

71 

- 90 % 

■ 

51 

- 70 % 

■ 

1 

- 50 % 



l • 

G^at Falls. MONTANA 
lL 'f ★Helena 
Bozeman A • Billings 


Gillette 


WYOMIN& 


IDAHQ 


USDA 



iteUbwy 

. Resource 
f Information System 


co 

LO 


Page 























Gallatin River Basin 

Monthly Precipitation and Reservoir Levels 
Percentage of Normal 
June 1,2019 (May 1, 2019 - June 1, 2019) 



LO 


Page 























Headwaters Mainstem (Missouri) River Basin 

Only three snowpack monitoring sites have snowpack remaining in the mountains surrounding Helena on June 1st, and 
these high elevation sites are above normal for snowpack on this date. Snowpack at these elevations is typically 40% to 
70% of the seasonal peak for this date, and totals are slightly above normal this year. These high elevation sites help to 
sustain flows as rivers recede from the "big push" of snowmelt from all elevations, so it's good news. Like many other 
regions in the state, eastern facing parts of mountain ranges received above-average precipitation during May, while 
other parts of these ranges experienced below-average precipitation. This is due to the counterclockwise flow of the 
low-pressure systems that dominated the latter half of the month. Valley locations were hit or miss, with Townsend 
reporting below average precipitation, while Helena was above average. Canyon Ferry Lake has been filling during the 
month of May and is currently 87% full. The weather ending May and beginning June (well above average temperatures) 
will likely cause the upstream rivers feeding the Missouri to make their final big push for the season. This should help to 
top off the reservoirs in the region. 



Headwaters Missouri Mainstem River Basin Data Summary 


Snowpack 

HEADWATERS MAINSTEM 

Percent of 1981-2010 
Normal (Median) 

Last Year Percentage of 
Normal (Median) 

122% 

100% 

Basin-Wide Snowpack 

123% 

84% 


Precipitation 

Mountain Precipitation 

Valley Precipitation 

Monthly Percentage of 
Average 

WYTD Percentage of 1981- 
2010 Average* 

WYTD Last Year 
Percentage of Average 

92% 

107% 

129% 

88% 

113% 

156% 

Basin-Wide Precipitation 

91% 

107% 

132% 


*Water Year-to-Date (WYTD) Precipitation is October 1st - Current 


Reservoir Storage 

Percentage of Average 

Percentage of Capacity 
(Total) 

Last Year Percentage of 
Average 

Basin-Wide Storage 

125% 

90% 

127% 


*See Reservoir Storage Table for storage in individual reservoirs 


LD 

LO 


Page 































(click on chart below to navigate to online version with additional features) 


Snow Water Equivalent in 


HEADWATERS MAIN STEM 

Jan Apr July WY 



Nov i Jan 1 Mar 1 May 1 


Jul 1 


Station List 

X Median Peak SWE 
— Max 

Median (POR) 
Median C'El-'lO) 

— Min 

Stats. Shading 

-2019 {5 sites) 

2013 (5 sites) 
- 2017 (5 sites) 

— 2016 (5 sites) 

-2015 (5 sites) 

-- 2014 {5 sites) 

I — 2013 (5 sites) 

- 2012 {5 sites) 

—— 2011 (5 sites) 

- 2010 {5 sites) 

; — 2009 {5 sites) 

— 2008 (5 sites) 

— 2007 {5 sites) 



Statistical shading breaks at 10th r 30th r 50th, 70th, and 90th Percentiles. 


For more information visit: 30 year normals calculation description. 


Mountain and Valley 
Precipitation 

M onthly ear-to -date 

200 
180 
160 
oj 140 

to 
ns 

§j 120 
< 

o 100 
80 
60 
40 
20 
0 

Oct Nov Dec Jan Feb Mar Apr May 



End of Month Reservoir 
Storage 

■ % Capacity ■ Avg % Capacity 


& 


□_ 

ro 


CJ 


— 

_Q 

ro 

ij-i 





Oct Nov Dec Jan Feb Mar Apr May 


Storage above is averaged for all reservoirs in the 
basin. For individual reservoirs see table below. 


kO 

i_n 


age 

























































Headwaters Mainstem (Missouri) River Basin 
Snow Water Equivalent 
Percentage of Normal 
June 1, 2019 



1 ^ 

LO 


Page 























Headwaters Mainstem (Missouri) River Basin 
Water Year to Date Precipitation and Reservoir Levels 
Percentage of Normal 
June 1, 2019 



Precipitation 
Percent of Normal 
SNOTEL COOP/ACIS 


• > 150% 

• 131-150% 
O 111-130% 

C 91 - 110% 


o 

71 - 90% 

• 

51 - 70% 

• 

1 - 50% 


# >150% 

0 131-150% 
0 111-130% 
0 91 - 110% 


® 

71 

- 90% 


51 

- 70% 

• 

1 

- 50% 


Reservoirs 
Percent of Normal 


■ 

> 150% 

□ 

131 

- 150% 

□ 

111 

- 130% 

□ 

91 

- 110% 

□ 

71 

- 90% 

■ 

51 

- 70% 

■ 

1 

- 50% 



USDA 



iteUbwy 

. Resource 
f Information System 


00 

LO 


Page 



















ihFpHcSwlW* 


Headwaters Mainstem (Missouri) River Basin 
Monthly Precipitation and Reservoir Levels 
Percentage of Normal 
June 1, 2019 (May 1, 2019 - June 1, 2019) 



Precipitation 
Percent of Normal 


SNOTEL 

• > 150% 

• 131-150% 

O 111-130% 
® 91 - 110% 


o 

71 - 90% 

• 

51 - 70% 

• 

1 - 50% 


COOP/ACIS 

+ >150% 

0 131-150% 
0 111-130% 
0 91 - 110% 


® 

71 ■ 

- 90% 


51 ■ 

- 70% 

• 

1 ■ 

- 50% 


Reservoirs 
Percent of Normal 


■ 

> 150% 


131 

- 150% 

□ 

111 

- 130% 

□ 

91 

- 110% 

□ 

71 

- 90% 

□ 

51 

- 70% 

■ 

1 ■ 

- 50% 



CT) 

LO 


Page 
























Smith-Judith-Musselshell River Basin 



Not that bragging about June 1st means a lot in the greater scheme of things, but snowpack in the Smith-Judith- 
Musselshell is the best, percentage-wise, in the state on this date. The significance of a high number for this date is that 
there's more water than normal remaining to enter the rivers, which is excellent news. Snowpack remains at the high 
elevations in the Little Belt and Big Belt mountains, with low and mid elevations melting out during the early weeks of 
May. Snowmelt began in earnest at all elevations in early May, but cooler weather mid-month helped to slow the melt 
at high elevation monitoring sites. SNOTEL sites in the east side of the Little Belts received near to slightly above average 
precipitation during the month, benefitting from upslope flow from the passing low-pressure systems, while other sites 
in the west side of the Little Belts and in Big Belt Range experienced below average precipitation. Seasonal snowmelt- 
driven peak flows on many rivers likely occurred on May 18th after the prolonged warm spell, but future peak flows 
could occur should a rain event coincide with the remaining melt from the high elevations. The great news is that 
excellent carryover storage and abundant snowpack this year has reservoirs full, or nearing full, on June 1st. Water users 
look to have adequate water supply this summer, barring an anomalously warm and dry summer. 


Smith Judith Musselshell River Basin Data Summary 


Snowpack 

Percent of 1981-2010 
Normal (Median) 

Last Year Percentage of 
Normal (Median) 

SMITH 

134% 

62% 

HIGHWOOD 

% 

% 

JUDITH 

166% 

76% 

MUSSELSHELL 

% 

% 

Basin-Wide Snowpack 

157% 

62% 


Precipitation 

Monthly Percentage of 
Average 

WYTD Percentage of 1981- 
2010 Average* 

WYTD Last Year 
Percentage of Average 

Mountain Precipitation 

82% 

102% 

116% 

Valley Precipitation 

141% 

128% 

156% 

Basin-Wide Precipitation 

93% 

105% 

121% 


*Water Year-to-Date (WYTD) Precipitation is October 1st - Current 


Reservoir Storage 

Percentage of Average 

Percentage of Capacity 
(Total) 

Last Year Percentage of 
Average 

Basin-Wide Storage 

149% 

104% 

148% 


*See Reservoir Storage Table for storage in individual reservoirs 


o 


Page 



































(click on chart below to navigate to online version with additional features) 


Snow Water Equivalent in 


SMTIH-JUDITH-MUSSELS HELL MOUNTAIN 

Jan Apr July WY 

Station List 



It Median Peak 5WE 
Max 

Median (POR) 
Median C'Bl-'lO) 

— Min 

Stats. Shading 
--- 2019 (9 sites) 

— 2018 (9 sites) 
- 2017 {9 sites) 

— 2016 (9 sites) 

-- 2015 (9 sites) 

-* 2014 (9 sites) 

— 2013 (9 sites) 

■ - 2012 (9 sites) 

■ -- 2011 (9 sites) 

— 2010 (9 sites) 

— 2009 {9 sites) 
2008 (9 sites) 

— 2007 {9 sites) 



Statistical shading breaks at 10th r 30th r 50th, 70th, and 90th Percentiles. 


For more information visit: 30 year normals calculation description. 


Mountain and Valley 
Precipitation 


i Monthly 


•Year-to-date 



End of Month Reservoir 
Storage 


I % Capacity 


Avg % Capacity 



Oct Nov Dec Jan Feb Mar Apr May 


Oct Nov Dec Jan Feb Mar Apr May 


Storage above is averaged for all reservoirs in the 
basin. For individual reservoirs see table below. 


^—I 

kD 


Page 










































Smith-Judith-Musselshell River Basin 
Snow Water Equivalent 
Percentage of Normal 
June 1, 2019 



Havre 


lelknap Agency 


[eton 




Lewistown 


Roundup] 


Forks 


Big Timber, 


Billings 


Laurel 


.Columbus 


.ivingston a> 


Crow Agency 


Lake 


Big Sky Meade 


helby 


Lake 

Elwell 

Haber 

Reservoir) 


Canyon 
Ferry> 
\Lake 


Townsend 




Bighorn 

Lake 


Snow Water Equivalent 
Percent of Normal 


SNOTEL Snowcourse 


• 

> 150% 

© 

71 - 90% 

+ 

> 150% 

* 

71 - 90% 

• 

131 -150% 

• 

51 - 70% 

* 

131 -150% 

+ 

51 - 70% 

c 

111 -130% 

• 

1 - 50% 

* 

111 -130% 

+ 

1 - 50% 

• 

91 -110% 

* 

0% 

* 

91 - 110% 

* 

0% 


wanspen 

.,lr F! >TOWNA 

JL f mietenay 

J Bozeman # Billings 


E Boise w—^ 

■sneriaan • Cilli 

ate 

'★'DAHO. 

WYOMING 

; 

^ 

• Cast 

fe- 


USDA 



eaojrce 
‘ Information System 


CM 

LD 


Page 




























Smith-Judith-Musselshell River Basin 
Water Year to Date Precipitation and Reservoir Levels 
Percentage of Normal 
June 1, 2019 



Havre 


ielknap Agency 




>rt Benton 


.5 acagt'yM 


•TcwnFen 


^Wo^stoM 


Forks 


tig Timber 


Manheftt 

Belgrai 


Hardin 


>zeman 


Colum bt 


.ivingston 


Crow Agency] 


helby 


L 

Eh, ell 121 

(Tiber ["] 
Reservoir) 


Bighorn, 

Lake 


Precipitation 
Percent of Normal 
SNOTEL COOP/ACIS 


• > 150% 

• 131-150% 
O 111-130% 

C 91 - 110% 


0 71 - 90% 

• 51 - 70% 

• 1 - 50% 


# >150% 

0 131-150% 
0 111-130% 
0 91 - 110% 


® 

71 ■ 

- 90% 


51 • 

- 70% 

• 

1 ■ 

- 50% 


Reservoirs 
Percent of Normal 


■ 

> 150% 

□ 

131 

- 150% 

□ 

111 

- 130% 

□ 

91 

- 110% 

□ 

71 

- 90% 

■ 

51 

- 70% 

■ 

1 

- 50% 



USDA 



tcLIbiwy 

. Resource 
f Information System 


no 

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Smith-Judith-Musselshell River Basin 
Monthly Precipitation and Reservoir Levels 
Percentage of Normal 
June 1,2019 (May 1, 2019 - June 1, 2019) 



Havre 


ip Agency 


'•Fort Benton 


t uri/&ver 


Roundup 


^Wo^sione 


ree Fortes 


)ig Timber 


lanhattan 


)zeman 


Columl 


Crow Agency; 


Sky Mead( 


145 


Lake 

Ehvell -J21 
(Tiber | [ 

Reservoir) 


Bighorn 

Lake 


Reservoirs 

Precipitation Percent of Normal 



Percent of Normal 




■ 

> 150% 

SNOTEL 



COOP/ACIS 




131 - 150% 

• 

> 150% 

o 

71 - 90% 

• 

> 150% 

® 

71 - 90% 

□ 

111 - 130% 

• 

131 - 150% 

• 

51 - 70% 

® 

131 -150% 

® 

51 - 70% 

□ 

91 - 110% 

c 

111 -130% 

• 

1 - 50% 

® 

111 -130% 

• 

1 - 50% 

□ 

71 - 90% 

• 

91 - 110% 



® 

91 - 110% 




51 -70% 









■ 

1 - 50% 



LD 


Page 





























Sun-Teton-Marias River Basin 



Talking about snow in the Rocky Mountain Front seems like a moot point after what happened during the latter half of 
May, but we'll summarize what's left on June 1st. Snowpack remains at two high elevation SNOTEL sites in the basin, but 
melt has been occurring throughout the month. During the latter half of the month, a low-pressure system ushered in 
copious amounts of moisture into the east Rocky Mountain Front. SNOTEL sites reported 4.5 to 9.5" of precipitation 
between May 15th and May 28th. This caused rapid rises in local rivers and streams, and widespread flooding in the 
area. This is the second year in a row that a late spring event inundated the town of Augusta with water, with Elk Creek 
overflowing its banks. As you might expect, reservoirs are full to capacity at this time. Streamflow forecasts in the basin 
indicate near to slightly below average volumes for the June 1st - September 30th period, but the weather patterns 
(summer precipitation and temperatures) are always a major player in how streamflows shape up in the later summer 
months. 


Sun-Teton-Marias River Basin Data Summary 


Snowpack 

Percent of 1981-2010 
Normal (Median) 

Last Year Percentage of 
Normal (Median) 

SUN 

171% 

189% 

TETON 

171% 

189% 

MARIAS 

59% 

55% 

Basin-Wide Snowpack 

82% 

83% 


Precipitation 

Mountain Precipitation 

Valley Precipitation 

Monthly Percentage of 
Average 

WYTD Percentage of 1981- 
2010 Average* 

WYTD Last Year 
Percentage of Average 

180% 

101% 

122% 

146% 

192% 

187% 

Basin-Wide Precipitation 

174% 

107% 

127% 


*Water Year-to-Date (WYTD) Precipitation is October 1st - Current 


Reservoir Storage 

Percentage of Average 

Percentage of Capacity 
(Total) 

Last Year Percentage of 
Average 

Basin-Wide Storage 

119% 

75% 

112% 


*See Reservoir Storage Table for storage in individual reservoirs 


LO 

CD 


Page 


































(click on chart below to navigate to online version with additional features) 


Snow Water Equivalent in 
SUN-TETON-MARIAS 

Jan Apr July WY 


13 

rr 

LU 


o 

c 

U) 


Nov 1 Jan 1 Mar 1 May 1 Jul 1 



Station List 

X Median Peak SWE 
Max 

Median (POR) 
Median fei-'lO] 

— Min 

Stats. Shading 

■-* 2019 {5 sites) 

2018 {4 sites) 
- 2017 {5 sites) 

— 2016 (5 sites) 

- 2015 {5 sites) 

-2014 {5 sites) 

— 2013 {5 sites) 

- -- 2012 {5 sites) 

-- 2011 {5 sites) 

— 2010 {5 sites) 

— 2009 {5 sites) 
2008 {5 sites) 

— 2007 {5 sites) 



Statistical shading breaks at 10th r 3Gth r 50th, 70th, an-d 90th Percentiles. 


For more information visit: 30 year normals calculation description. 


Mountain and Valley 
Precipitation 

Monthly Year-to-date 



End of Month Reservoir 
Storage 

M% Capacity ■ Avg % Capacity 



Oct Nov Dec Jan Feb Mar Apr May 


Storage above is averaged for all reservoirs in the 
basin. For individual reservoirs see table below. 


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Sun-Teton-Marias River Basin 
Snow Water Equivalent 
Percentage of Normal 



Snow Water Equivalent 
Percent of Normal 


SNOTEL Snowcourse 


• 

> 150% 

G 

71 - 90% 

+ 

> 150% 

* 

71 - 90% 

• 

131 -150% 

• 

51 - 70% 

* 

131 -150% 

+ 

51 - 70% 

C- 

111 -130% 

• 

1 - 50% 

* 

111 -130% 

+ 

1 - 50% 

• 

91 -110% 

* 

0% 

* 

91 - 110% 

* 

0% 


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Page 









































Sun-Teton-Marias River Basin 
Water Year to Date Precipitation and Reservoir Levels 
Percentage of Normal 
June 1, 2019 



Precipitation 
Percent of Normal 


SNOTEL 

• > 150% 

• 131-150% 

O 111-130% 
® 91 - 110% 


0 71 - 90% 

• 51 - 70% 

• 1 - 50% 


COOP/ACIS 

+ >150% 

0 131-150% 
0 111-130% 
0 91 - 110% 




71 - 90% 
51 - 70% 
1 - 50% 


Reservoirs 
Percent of Normal 


■ 

> 150% 

□ 

131 

- 150% 

□ 

111 

- 130% 

□ 

91 

- 110% 

□ 

71 

- 90% 

■ 

51 

- 70% 

■ 

1 

- 50% 



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Sun-Teton-Marias River Basin 
Monthly Precipitation and Reservoir Levels 
Percentage of Normal 
June 1,2019 (May 1, 2019 - June 1, 2019) 



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St. Mary-Milk River Basin 



High elevation snowpack in the St. Mary River basin peaked below normal this year and is melting earlier than normal. 
Melt occurred throughout the month at the Flattop Mountain SNOTEL site, located in Glacier National Park, but a brief 
return to cooler weather mid-month helped to delay what looked to be very early and rapid snowmelt. At this time, 
about 50% of the high elevation snowpack remains to enter the river systems over the coming month, and warm 
temperatures at the end of May and beginning of June have accelerated the snowmelt. Water Year precipitation is 
below normal at both high and low elevations in the region, with Flattop Mountain experiencing further declines after 
only 43% of average precipitation fell during May. Water supply is anticipated to be below average this summer due to 
the below average water year precipitation, and below normal peak snowpack. 


St. Mary-Milk River Basin Data Summary 


Snowpack 

Percent of 1981-2010 
Normal (Median) 

Last Year Percentage of 
Normal (Median) 

ST. MARY 

73% 

102% 

BE ARP AW MOUNTAINS 

% 

% 

MILK RIVER BASIN 

% 

% 

Basin-Wide 

73% 

102% 


Precipitation 

Mountain Precipitation (St. Mary) 

Mountain Precipitation (Bearpaw Mtns) 

Valley Precipitation 

Monthly Percentage of 
Average 

WYTD Percentage of 
1981-2010 Average* 

WYTD Last Year 
Percentage of 
Average 

70% 

81% 

111% 

31% 

91% 

102% 

79% 

115% 

136% 

Basin-Wide Precipitation 

62% 

85% 

112% 


*Water Year-to-Date (WYTD) Precipitation is October 1st - Current 


Reservoir Storage 

Percentage of Average 

Percentage of Capacity 
(Total) 

Last Year Percentage 
of Average 

Basin-Wide Storage 

133% 

74% 

138% 


o 


Page 



































(click on chart below to navigate to online version with additional features) 


Snow Water Equivalent in 


ST. MARY 

Jan Apr July WY 



Nov 1 Jan 1 Mar 1 May L Jul 1 


Station List 

K Median Peak 5WE 
Max 

Median (POR) 
Median C'Sl-'lO) 

— Min 

Stats. Shading 

--2019 (2 sites) 

- 2018 (2 sites) 

— 2017 (2 sites) 

— 2016 {2 sites) 

-- 2015 (2 sites) 

-2014 (2 sites) 

— 2013 (2 sites) 

- - 2012 (2 sites) 

— 2011 (2 sites) 

- 2010 (2 sites) 

-- 2009 (2 sites) 

- 2008 (2 sites) 

— 2007 (2 sites) 



Statistical shading breaks at 10th r 30th r 50th, 70th, and 90th Percentiles. 


For more information visit: 30 year normals calculation description. 


Mountain and Valley 
Precipitation 

Monthly ^^"Year-to-date 



Oct Nov Dec Jan Feb Mar Apr May 


End of Month Reservoir 
Storage 

M% Capacity ■ Avg % Capacity 



Oct Nov Dec Jan Feb Mar Apr May 


Storage above is averaged for all reservoirs in the 
basin. For individual reservoirs see table below. 


^—I 


Page 





























































St Mary's-Milk River Basin 
Snow Water Equivalent 
Percentage of Normal 
June 1, 2019 



Travers 

Reservoir 


Crane Lake 


bridge 


v-gyt chnian. 


Pakowla 


Montan 


Reservoir 


Havre 


Lake 
Elwell 
(Tiber 
Reservoir) 


Choteau 


N -^544^ 

Tide Lake 


y Mary 

/ Island _ • 

Medicine Hat r ■ Bitter Lake 


Lake \ 
McDonald 


Hungry' v* 
Horse 

Reservoir ■ 


Big fork 


Flathead 

Lake 

78 


River 


0 m 


a /\> s 


Ronan 'S 


Snow Water Equivalent 
Percent of Normal 


SNOTEL 


• 

> 150% 

G 

71 - 90% 

• 

131 -150% 

• 

51 - 70% 

C- 

111 -130% 

• 

1 - 50% 

• 

91 -110% 

* 

0% 


Snowcourse 


+ 

> 150% 

* 

71 - 90% 

* 

131 -150% 

+ 

51 - 70% 

* 

111 -130% 

+ 

1 - 50% 

* 

91 - 110% 

* 

0% 




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St Mary's-Milk River Basin 

Water Year to Date Precipitation and Reservoir Levels 
Percentage of Normal 
June 1, 2019 



Travel 
Reservoir . _ 


iprejjy^ lic ;iman 


Pakowh 


Montan' 


H&qsno 

Reservoir 


Chinook 


Havre 


Reservoir) 


Choteau* 


>rt Bentoj 


• Seeley Lake 


1 rt 



\p 


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^550W 




- ^544^ 

Tide Lake 


Mam 



~~^524^ 

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>yMedic>ne Hat Bitter Lake 

Crane Lake • 


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V [ ^--f 





/ _ k rrirTHf _ 



1. 1 

Pvt7 

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r 




Lake 

McDonald 

79 $> . 

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15 \£ffungry ^ 
Horse 
Reservoir 

85 

•Big fork 


Flathead 

Lake 


. M\$- 


0 MTi R™ 


River 


»Ronan 

99 | 


Precipitation 
Percent of Normal 
SNOTEL COOP/ACIS 


• > 150% 

• 131-150% 
O 111-130% 

C 91 - 110% 


O 

71 - 90% 

• 

51 - 70% 

• 

1 - 50% 


# >150% 

0 131-150% 
0 111-130% 
0 91 - 110% 


® 

71 

- 90% 


51 

- 70% 

• 

1 

- 50% 


Reservoirs 
Percent of Normal 


■ 

> 150% 

□ 

131 

- 150% 

□ 

111 

- 130% 

□ 

91 

- 110% 

□ 

71 

- 90% 

■ 

51 

- 70% 

■ 

1 

- 50% 



USDA 



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St Mary's-Milk River Basin 
Monthly Precipitation and Reservoir Levels 
Percentage of Normal 
June 1,2019 (May 1, 2019 - June 1, 2019) 





Page 






































































Upper Yellowstone River Basin 



The Upper Yellowstone has had its ebbs and flows like many other drainages around southern Montana this winter, but 
its finishing up spring with a bang in the Clark's Fork and Rock Creek, as both received above average precipitation in 
May. High elevation snowpack also peaked in the first week of May across the region, while low to mid elevations where 
predominantly snow free by the 10 th . This high elevation snowpack still sits at 133% of normal basin wide, which spells a 
favorable run-off season as overnight lows continue to remain above freezing, even at the upper reaches of the basin. 
The Yellowstone River has already seen it's low elevation snow water pulse, and as this high elevation snowpack begins 
to enter the streams and tributaries, it should reach another crest soon. Even with above average snowpack melting out 
of the mountains, we still need average precipitation in coming months to help to sustain flows throughout the summer. 


Upper Yellowstone River Basin Data Summary 


Snowpack 

YELLOWSTONE ab LIVINGSTON 

SHIELDS 

BOULDER-STILLWATER 

RED LODGE-ROCK CREEK 

CLARK'S FORK 

Percent of 1981-2010 
Normal (Median) 

Last Year Percentage of 
Normal (Median) 

129% 

127% 

174% 

30% 

110% 

99% 

211% 

7% 

136% 

155% 

Basin-Wide Snowpack 

133% 

117% 


Precipitation 

Monthly Percentage of 
Average 

WYTD Percentage of 1981- 
2010 Average* 

WYTD Last Year 
Percentage of Average 

Mountain Precipitation 

91% 

108% 

129% 

Valley Precipitation 

135% 

129% 

157% 

Basin-Wide Precipitation 

102% 

111% 

134% 


*Water Year-to-Date (WYTD) Precipitation is October 1st - Current 


Reservoir Storage 

Percentage of Average 

Percentage of Capacity 
(Total) 

Last Year Percentage 
of Average 

Basin-Wide Storage 

119% 

103% 

119% 


LD 


Page 




































(click on chart below to navigate to online version with additional features) 


Snow Water Equivalent in 
YELLOWSTONE ab LIVINGSTON 

Jan Apr July WY 



Station List 

U Median Peak 5WE 
Max 

Median (POR) 
Median C81- B 10) 

— Min 

Stats. Shading 

-2019 (10 sites) 

----- ■ = ■ 2018 (9 sites) 

— 2017 (10 sites) 
-• 2016 (10 sites) 

— 2015 (9 sites) 

— 2014 (9 sites) 

— 2013 (10 sites) 

— 2012 (10 sites) 

— 2011 (10 sites) 

— 2010 (10 sites) 

- 2009 (10 sites) 

— 2008 (10 sites) 

| - 2007 (10 sites) 



Statistical shading breaks at 10th r 30th r 5Gth, 70th, and 90th Percentiles. 


For more information visit: 30 year normals calculation description. 


Mountain and Valley 
Precipitation 

I Monthly ^^Year-to-date 


End of Month Reservoir Storage 


■ % Capacity ■ Avg % Capacity 



Oct Nov Dec Jan Feb Mar Apr May 



t 


1 

J 


II 


_ 

1 . 

. 

_ s 


■ 1 II II 


Oct Nov Dec Jan Feb Mar Apr May 

Storage above is averaged for all reservoirs in the 
basin. For individual reservoirs see table below. 


to 


Page 




































































Upper Yellowstone River Basin 
Snow Water Equivalent 
Percentage of Normal 
June 1, 2019 



Woundup 


Y$lo}Vsp ne 


Big Timber 


Billings 


Hardin 


:eman 


Livingston 


Crow Agencyj 


Wyoming 


Powell 


>t Yellowstom 


Yellowstone 




Bighorn 

Lake 

__ * 


Jackson 

Lake 


Snow Water Equivalent 
Percent of Normal 


SNOTEL Snowcourse 


• 

> 150 % 

G 

71 - 90 % 

+ 

> 150 % 

* 

71 - 90 % 

• 

131 - 150 % 

• 

51 - 70 % 

* 

131 - 150 % 

+ 

51 - 70 % 

C- 

111 - 130 % 

• 

1 - 50 % 

* 

111 - 130 % 

+ 

1 - 50 % 

• 

91 - 110 % 

* 

0 % 

* 

91 - 110 % 

* 

0 % 


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Page 
































Upper Yellowstone River Basin 
Water Year to Date Precipitation and Reservoir Levels 
Percentage of Normal 
June 1, 2019 



.Roundup 


Y jlfco x'stone 


Timber 


Hardin 


>zeman 


Colum! 


Crow Agency i 


Powell 


Yellows to-> 
^jt&ke 


Jackson 

Lake 


Bighorn 

Lake Montana 
Wyoming 


119 
C l|07 


Precipitation 
Percent of Normal 


SNOTEL 

• > 150 % 

• 131 - 150 % 

O 111 - 130 % 
% 91 - 110 % 


o 

71 - 90% 

• 

51 - 70% 

• 

1 - 50% 


COOP/ACIS 

+ > 150 % 

0 131 - 150 % 
0 111 - 130 % 
0 91 - 110 % 


® 

71 ■ 

- 90 % 


51 • 

- 70 % 

• 

1 ■ 

- 50 % 


Reservoirs 
Percent of Normal 


■ 

> 150 % 

□ 

131 

- 150 % 

□ 

111 

- 130 % 

□ 

91 

- 110 % 

□ 

71 

- 90 % 

■ 

51 

- 70 % 

■ 

1 

- 50 % 



oo 


Page 


























Upper Yellowstone River Basin 
Monthly Precipitation and Reservoir Levels 
Percentage of Normal 
June 1,2019 (May 1, 2019 - June 1, 2019) 



Roundu) 




Mg Timber 


Mgrade 


Hardin 


lozeman 


Livingston 


Colum 


Crow Agency* 


Montana 


Wyoming 


136 


Powell 


Yellowstone 

Lake 


Jvcnvoorf q 


Jackson 

Lake 


Precipitation 
Percent of Normal 


SNOTEL 


COOP/ACIS 


• > 150% 

• 131-150% 
O 111-130% 
% 91 - 110% 


0 71 - 90% 

• 51 - 70% 

• 1 - 50% 


# >150% 

0 131-150% 
0 111-130% 
0 91 - 110% 


® 

71 ■ 

- 90% 


51 ■ 

- 70% 

• 

1 ■ 

- 50% 


Reservoirs 
Percent of Normal 


■ 

> 150% 


131 

- 150% 

□ 

111 

- 130% 

□ 

91 

- 110% 

□ 

71 

- 90% 

□ 

51 

- 70% 

■ 

1 ■ 

- 50% 



CT) 


Page 



























Lower Yellowstone River Basin 



Just when it seemed like winter was over, it came roaring back into the sub-basins that make up the Lower Yellowstone 
River basin. Snowpack accumulated in the mountains during the first two weeks of the month, before warmer weather 
began the melt at most elevations. Shortly after the snowpack seemed like it was on the way, out a slow-moving low- 
pressure system delivered incredible amounts of mountain snow and valley precipitation for late May. In general, 
SNOTEL sites in the Wind River Range and the Absaroka Range received 2.3" to 8 . 7 " of snow water equivalent during this 
storm cycle and up to 27 ” of snow. Further east in the Bighorn Range, the storm fell as a mix of rain in the valleys and at 
low elevations in the mountains, and snowfall at mid and high elevation sites. Up to 4.7" of snow water equivalent was 
added to the snowpack at high elevations, and up to 7 . 1 " of precipitation fell elsewhere. Monthly precipitation for May 
was amazing, ranging from 142% to 375% of average, and helped almost all areas to recover from the deficits 
experienced so far this winter and spring with regards to water-year precipitation (October 1st - current). It doesn't 
matter when you get it, as long as you get it. 

As you might expect, all this water did cause its share of problems. Some rivers and creeks broke free of their banks in 
north-central during the end of the month in response to the heavy rainfall at lower elevations. On the bright side, the 
increases in snowpack in the mountains should help to fill reservoirs across the region and ensure adequate water 
supply for the coming summer. 


Lower Yellowstone River Basin Data Summary 


Snowpack 

Percent of 1981-2010 
Normal (Median) 

Last Year Percentage of 
Normal (Median) 

WIND RIVER BASIN 

301% 

88% 

SHOSHONE RIVER BASIN 

151% 

121% 

BIGHORN RIVER BASIN 

181% 

88% 

LITTLE BIGHORN BASIN 

202% 

40% 

TONGUE RIVER BASIN 

368% 

40% 

POWDER RIVER BASIN 

449% 

10% 

Basin-Wide Snowpack 

254% 

84% 


Precipitation 

Monthly Percentage of 
Average 

WYTD Percentage of 1981- 
2010 Average* 

WYTD Last Year 
Percentage of Average 

Mountain Precipitation 

187% 

105% 

107% 

Valley Precipitation 

192% 

132% 

126% 

Basin-Wide Precipitation 

189% 

113% 

113% 


*Water Year-to-Date (WYTD) Precipitation is October 1st - Current 


Reservoir Storage 

Percentage of Average 

Percentage of Capacity 
(Total) 

Last Year Percentage of 
Average 

Basin-Wide Storage 

108% 

68% 

113% 


oo 


Page 




































(click on chart below to navigate to online version with additional features) 


Jan 


Snow Water Equivalent in 
LOWER YELLOWSTONE RIVER BASIN (Wyoming) 

Apr July 


WY 



Median Peak SWE 
Max 

Median (POR) 
Median ['Sl-'IQ) 

■ Min 

Stats. Shading 

■ 2019 (30 sites) 
■2013 (29 sites) 
■2017 (30 sites) 
■2016 (30 sites) 

■ 2015 (29 sites) 

■ 2014 (29 sites) 
2013 (30 sites) 
2012 (30 sites) 

■2011 (30 sites) 
2010 (30 sites) 

■ 2009 (30 sites) 

■ 2003 (30 sites) 

■ 2007 (30 sites) 


Nov 1 


Jan 1 


Mar 1 


May 1 


Jul 1 


Statistical shading breaks at 10th r 30th r 50th, 70th, and 90th Percentiles. 
For mere information visit: 30 year normals calculation description. 


Mountain and Valley 
Precipitation 


Monthly 


•Year-to-date 


80 

60 

40 

20 

0 


■ 111111 
1111111 




Oct Nov Dec Jan Feb Mar Apr May 


End of Month Reservoir Storage 


I % Capacity 


Avg % Capacity 



Oct Nov Dec Jan Feb Mar Apr May 

Storage above is averaged for all reservoirs in the 
basin. For individual reservoirs see table below. 


^—I 

00 


Page 
















































Lower Yellowstone River Basin 
Snow Water Equivalent 
Percentage of Normal 
June 1, 2019 



\U$sO xC 


Joundup 


Colstrip 


Billings 


Timber 


Lame Deer 


lardin 


nngston 


'BigJytm 
Sake j • 

i 7 y 

Montana 

Wyoming 


110 123 


iSheridan 


Lake 


lacks on 
y ~Lake 


Snow Water Equivalent 
Percent of Normal 


Lewistown 


124 


Wo 


SNOTEL 


• 

> 150 % 

G 

71 - 90 % 

• 

131 - 150 % 

• 

51 - 70 % 

C- 

111 - 130 % 

• 

1 - 50 % 

• 

91 - 110 % 

* 

0 % 


Snowcourse 


+ 

> 150 % 

* 

71 - 90 % 

* 

131 - 150 % 

+ 

51 - 70 % 

* 

111 - 130 % 

+ 

1 - 50 % 

* 

91 - 110 % 

* 

0 % 



USDA 



eaojrce 
‘ Information System 


CM 

00 


Page 






































Lower Yellowstone River Basin 
Water Year to Date Precipitation and Reservoir Levels 
Percentage of Normal 
June 1, 2019 



no 

oo 


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Lower Yellowstone River Basin 
Monthly Precipitation and Reservoir Levels 
Percentage of Normal 
June 1,2019 (May 1, 2019 - June 1, 2019) 





isTOWrr 


toundup 


150 

0olstnp 


imber 


' Big habi 
Lake 


Montana 


J63 Wyoming 


[owstoi 


Newcastle 


Jackson 

KLake 


,, 124 12 9 159 

43W 73 ® 




Precipitation 
Percent of Normal 


SNOTEL 


COOP/ACIS 


• > 150% 

• 131-150% 
O 111-130% 
C 91 - 110% 


o 

71 - 90% 

• 

51 - 70% 

• 

1 - 50% 


# >150% 

0 131-150% 
0 111-130% 
0 91 - 110% 


® 

71 ■ 

- 90% 


51 ■ 

- 70% 

• 

1 ■ 

- 50% 


Reservoirs 
Percent of Normal 


■ 

> 150% 


131 

- 150% 

□ 

111 

- 130% 

□ 

91 

- 110% 

□ 

71 

- 90% 

□ 

51 

- 70% 

■ 

1 ■ 

- 50% 



oo 


CD 

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03 

Cl 


































Issued by: 


Released by: 


Tom Watson 
State Conservationist 
Natural Resources Conservation Service 
Bozeman, Montana 

Report Created by: 

Montana Snow Survey Staff 
10 East Babcock St, Room 443 
Bozeman, MT 59715 
Email: MT-nrcs-snow@one.usda.gov 


Matt Lohr 
Chief 

Natural Resources Conservation Service 
U.S. Department of Agriculture 




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