New 1991-2020 Averages being used this year.
Green Water Supply Outlook, April 1, 2022

Green Water Supply Outlook, April 1, 2022

Note: This publication is scheduled for revision. If you have feedback on content, format, or publication frequency, please contact us.
Prepared by Brenda Alcorn
NOAA, National Weather Service
Colorado Basin River Forecast Center
Salt Lake City, Utah
www.cbrfc.noaa.gov

Contents

Green Summary




*Median of forecasts within each basin.


Upper Green Basin Conditions




Snow Water Equivalent in Percent of Median.
* Percent usable capacity, not percent average contents.
Click for multi-month Graph.

Yampa/White Basin Conditions




Snow Water Equivalent in Percent of Median.
* Percent usable capacity, not percent average contents.
Click for multi-month Graph.

Duchesne Basin Conditions




Snow Water Equivalent in Percent of Median.
* Percent usable capacity, not percent average contents.
Click for multi-month Graph.

Lower Green Basin Conditions




Snow Water Equivalent in Percent of Median.
* Percent usable capacity, not percent average contents.
Click for multi-month Graph.


Upper Green Specific Site Forecasts (kaf)

Click site name for graph.
Forecast
Period		90%
Exceedance
Volume		70%
Exceedance
Volume		50%
Exceedance
Volume		Percent
Average		30%
Exceedance
Volume		10%
Exceedance
Volume
Green
Daniel, Nr, Warren Bridge, At April-July140 160 180 71 200 225
Pine Ck
Fremont Lk, Abv April-July47 55 66 65 76 86
New Fork
Big Piney, Nr April-July105 140 175 49 220 285
Green
Fontenelle Reservoir, Fontenelle, Nr April-July260 335 435 59 510 585
Big Sandy
Farson, Nr April-July16 22 27 54 34 45
Green
Green River, Wy, Nr April-July260 320 425 58 525 615
Hams Fork
Frontier, Nr, Pole Ck, Blo April-July17 20 24 46 30 38
Viva Naughton Reservoir April-July20 23 28 38 36 48
Blacks Fork
Robertson, Nr April-July50 56 64 73 75 93
Ef Smiths Fork
Stateline Reservoir, Robertson,nr April-July15 17 20 71 23 27
Green
Flaming Gorge Reservoir April-July360 400 520 54 680 860


Yampa/White Specific Site Forecasts (kaf)

Click site name for graph.
Forecast
Period		90%
Exceedance
Volume		70%
Exceedance
Volume		50%
Exceedance
Volume		Percent
Average		30%
Exceedance
Volume		10%
Exceedance
Volume
Yampa
Stagecoach Rsvr, Abv April-July19 21 23 85 25 28
Steamboat Springs April-July140 165 185 71 210 245
Elk
Milner, Nr April-July230 265 285 86 330 365
Elkhead Ck
Long Gulch, Abv, Hayden, Nr April-July40 50 55 77 64 77
Yampa
Maybell, Nr April-July530 625 680 74 805 905
Little Snake
Slater, Nr April-July88 105 115 74 130 170
Dixon, Nr April-July155 190 215 65 260 345
Lily, Nr April-July160 195 220 68 275 370
Yampa
Deerlodge Park April-July700 825 920 77 1100 1270
White
Meeker, Nr April-July155 180 195 75 230 275
Watson, Nr April-July150 175 190 70 230 280


Duchesne Specific Site Forecasts (kaf)

Click site name for graph.
Forecast
Period		90%
Exceedance
Volume		70%
Exceedance
Volume		50%
Exceedance
Volume		Percent
Average		30%
Exceedance
Volume		10%
Exceedance
Volume
Big Brush Ck
Vernal, Nr, Red Fleet Res, Abv April-July9.5 11 14 71 16.7 21
Ashley Ck
Vernal, Nr April-July20 23 30 65 38 51
West Fork Duchesne
Vat Diversion, Blo April-July9.5 11 12.5 74 14.5 17.5
Duchesne
Tabiona, Nr April-July65 70 75 73 85 103
Rock Ck
Upper Stillwater Reservoir April-July48 52 60 83 70 85
South Fork Rock Ck
Docs Div, Blo April-July4 4.5 5.5 75 6.5 8
Rock Ck
Mountain Home, Nr April-July58 63 72 83 85 102
Currant Ck
Currant Ck Reservoir April-July9 11 14 79 17 23
Strawberry
Strawberry Reservoir, Soldier Springs April-July18 23 30 50 35 51
Starvation Reservoir, Duchesne, Nr April-July28 35 45 48 75 100
Duchesne
Duchesne, Nr, Knight Div, Abv April-July120 130 145 77 170 205
Lake Fork
Moon Lake Reservoir, Mtn Home, Nr April-July36 41 50 78 58 70
Yellowstone
Altonah, Nr April-July37 42 50 83 58 71
Whiterocks
Whiterocks, Nr April-July30 35 40 78 53 65
Uinta
Neola, Nr April-July40 47 58 81 71 90
Duchesne
Myton April-July140 165 195 64 260 350
Randlett, Nr April-July150 170 205 59 275 385


Lower Green Specific Site Forecasts (kaf)

Click site name for graph.
Forecast
Period		90%
Exceedance
Volume		70%
Exceedance
Volume		50%
Exceedance
Volume		Percent
Average		30%
Exceedance
Volume		10%
Exceedance
Volume
White
Blo Tabbyune Ck, Soldier Summit, Nr April-July5.5 7 8 63 9.5 14
Fish Ck
Scofield, Nr, Reservoir, Abv April-July17 19 21 81 25 34
Price
Scofield Reservoir, Scofield, Nr April-July21 24 27 79 31 45
Green
Green River, Ut April-July1380 1560 1800 64 2300 2900
Huntington Ck
Electric Lake April-July6.5 8 9 80 11 14
Power Plant, Blo April-July28 30 33 83 40 50
Seeley Ck
Joes Vly Reservoir, Orangeville, Nr April-July31 33 36 71 42 51
Ferron Ck
Ferron, Nr April-July18 21 24 69 27 35
Muddy Ck
Emery, Nr April-July9 10 11 60 12.5 15.5

Differences between the full period forecasts and the residual forecasts may not exactly equal the actual observed volumes due to rounding conventions (see Definitions section).

Green End of Month Reservoir Contents (kaf)

EOM
Contents		Percent
EOM
Average		Percent
Usable
Capacity		Last Year
EOM		Last Year
%Average		EOM
Average		Usable
Capacity
untitled Green
Fontenelle Reservoir, Fontenelle, Nr 151.4 117 45 120.9 94 129.2 334.0
untitled Big Sandy
Big Sandy Reservoir, Nr Farson 8.4 43 22 9.2 47 19.7 38.3
Blacks Fork
Meeks Cabin 12.7 94 42 6.0 44 13.6 29.9
untitled Ef Smiths Fork
Stateline Reservoir, Robertson,nr 6.0 106 43 4.0 71 5.6 13.9
untitled Green
Flaming Gorge Reservoir 2932.9 95 78 3168.0 103 3079.2 3749.0
untitled Strawberry
Strawberry Reservoir, Soldier Springs 841.2 103 76 928.5 114 816.9 1105.9
Starvation Reservoir, Duchesne, Nr 150.8 99 91 161.3 106 151.7 165.3
untitled Rock Ck
Upper Stillwater Reservoir 3.4 70 11 2.0 42 4.8 31.4
untitled Lake Fork
Moon Lake Reservoir, Mtn Home, Nr 27.3 120 75 14.2 62 22.8 36.5
untitled Big Brush Ck
Red Fleet Reservoir, Vernal, Nr 11.5 62 45 16.6 89 18.7 25.7
untitled Price
Scofield Reservoir, Scofield, Nr 21.0 76 32 36.1 130 27.7 65.8
untitled Seeley Ck
Joes Vly Reservoir, Orangeville, Nr 22.9 59 37 38.5 99 38.8 62.5
untitled Huntington Ck
Electric Lake 10.4 61 33 18.6 109 17.0 31.5
untitled
TOTAL 4199.9 97 74 4523.8 104 4345.5 5689.6

Precipitation Maps




Definitions

10% exceedance forecast: Given the current hydrometeorological conditions, i.e current snowpack, soil moisture and streamflow, the volume that has a 10% chance of being exceeded. Previously referred to as "Reasonable Maximum Forecast".

50% exceedance forecast: Given the current hydrometeorological conditions, i.e current snowpack, soil moisture and streamflow, the volume that has a 50% chance of being exceeded. Previously referred to as "Most Probable Forecast".

90% exceedance forecast: Given the current hydrometeorological conditions, i.e current snowpack, soil moisture and streamflow, the volume that has a 90% chance of being exceeded. Previously referred to as "Reasonable Minimum Forecast".

Acre-Foot (af): The volume equal to one acre covered one foot deep (43,560 cubic feet). See kaf below.

Average: The arithmetic mean. The sum of the values divided by the number of values. Values from 1991-2020 are used for this publication.

Categories: Much Above Average=Greater than 130%, Above Average=111-130%, Near Average=90-110%, Below Average=70-89%, Much Below Average=Less than 70%.

CBRFC: Colorado Basin River Forecast Center.

Forecast Period: The period from April 1 through July 31, unless otherwise noted.

kaf: Thousand Acre-Feet. See Acre-Foot above.

Inflow: The volume of water that flows into a reservoir or lake.

Median: The middle value of an ordered set of values. Half of the values are higher and half of the values are lower. When the set contains an even number of values the median is the average of the two middle numbers.

NOAA: National Oceanic and Atomospheric Administration.

NWS: National Weather Service.

Rounding Conventions:
RangeRound to
0-1.990.01
2.0-19.90.1
20-1991.0
200-9995.0
1000+3 significant digits


Streamflow: The volume of water that flows past a specific stream site.

Water Year: The 12-month period, October 1 through September 30. The water year is designated by the calendar year in which it ends. Thus, the year ending September 30, 2008, is called the "2008 water year."


Additional Information

Water supply forecasts take into consideration present hydrometeorological conditions and use average basin temperatures and precipitation for the forecast period. As the forecast season progresses, a greater portion of the future hydrologic and climatic uncertainty becomes known and monthly forecasts become more accurate. For more information on the tools we use, consult Water Supply Forecasting Tools.

Volume forecasts represent adjusted flows; that is, observed flows with upstream water use taken into account. Adjusted flows will closely approximate natural or unimpaired flows. However, not all upstream diversions or impoundments are measured or quantifiable. For specific adjustments used with each forecast point, consult the Guide to Water Supply Forecasting.

The Water Supply Outlook is issued monthly January through May by the Colorado Basin River Forecast Center. It represents a coordinated effort between the National Weather Service, Natural Resources Conservation Service, Bureau of Reclamation, U.S. Geological Survey and local water district managers.

Note: Data used in this report are provisional and are subject to revision.

For more information, or to be included on the mailing list, please contact:

Colorado Basin River Forecast Center
2242 W North Temple
Salt Lake City, UT 84116
(801) 524-5130
www.cbrfc.noaa.gov


Hydrologist: Brenda Alcorn