Green Water Supply Outlook, February 1, 2023

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-July145 185 220 86 250 315
Pine Ck
Fremont Lk, Abv April-July69 78 88 87 98 115
New Fork
Big Piney, Nr April-July205 265 315 89 385 435
Green
Fontenelle Reservoir, Fontenelle, Nr April-July400 550 650 88 800 995
Big Sandy
Farson, Nr April-July31 42 50 100 58 70
Green
Green River, Wy, Nr April-July400 550 650 88 850 1020
Hams Fork
Frontier, Nr, Pole Ck, Blo April-July35 45 55 106 70 85
Viva Naughton Reservoir April-July47 60 75 103 105 130
Blacks Fork
Robertson, Nr April-July68 77 88 100 105 120
Ef Smiths Fork
Stateline Reservoir, Robertson,nr April-July22 25 28 100 34 38
Green
Flaming Gorge Reservoir April-July580 745 880 91 1270 1500


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
Steamboat Springs April-July260 300 325 125 365 430
Elk
Milner, Nr April-July370 405 455 138 500 575
Elkhead Ck
Long Gulch, Abv, Hayden, Nr April-July85 100 120 169 135 155
Yampa
Maybell, Nr April-July950 1090 1250 136 1430 1650
Little Snake
Slater, Nr April-July155 170 195 126 230 250
Lily, Nr April-July345 395 450 138 560 650
Yampa
Deerlodge Park April-July1290 1480 1700 143 2000 2200
White
Meeker, Nr April-July275 300 330 127 375 490
Watson, Nr April-July285 325 355 131 410 560


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-July15 20 23 117 28 34
Ashley Ck
Vernal, Nr April-July35 45 55 120 65 82
West Fork Duchesne
Vat Diversion, Blo April-July17 22 25 147 28 35
Duchesne
Tabiona, Nr April-July95 107 120 117 135 163
Rock Ck
Upper Stillwater Reservoir April-July65 72 80 111 98 125
South Fork Rock Ck
Docs Div, Blo April-July6.4 7.5 8.5 116 10 12.2
Rock Ck
Mountain Home, Nr April-July80 90 100 115 120 150
Currant Ck
Currant Ck Reservoir April-July18 22 28 158 33 42
Strawberry
Strawberry Reservoir, Soldier Springs April-July44 60 70 117 88 105
Starvation Reservoir, Duchesne, Nr April-July75 103 125 133 155 210
Duchesne
Duchesne, Nr, Knight Div, Abv April-July175 200 220 117 250 310
Lake Fork
Moon Lake Reservoir, Mtn Home, Nr April-July54 60 70 109 80 107
Yellowstone
Altonah, Nr April-July50 60 70 117 80 103
Whiterocks
Whiterocks, Nr April-July40 50 65 127 75 91
Uinta
Neola, Nr April-July57 75 90 125 100 130
Duchesne
Myton April-July240 310 370 121 470 650
Randlett, Nr April-July270 350 440 126 530 770


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-July12 16 21 167 25 32
Fish Ck
Scofield, Nr, Reservoir, Abv April-July32 38 45 173 50 60
Price
Scofield Reservoir, Scofield, Nr April-July42 50 60 176 70 90
Green
Green River, Ut April-July2500 3000 3500 125 4300 5400
Huntington Ck
Electric Lake April-July15 17.5 20 177 23 27
Power Plant, Blo April-July45 50 55 138 63 78
Seeley Ck
Joes Vly Reservoir, Orangeville, Nr April-July50 58 64 125 70 87
Ferron Ck
Ferron, Nr April-July32 36 41 117 47 60
Muddy Ck
Emery, Nr April-July15 18 21 115 25 32

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 166.8 101 50 180.2 109 165.5 334.0
untitled Big Sandy
Big Sandy Reservoir, Nr Farson 7.5 44 20 6.5 38 16.9 38.3
Blacks Fork
Meeks Cabin 9.5 83 32 10.5 92 11.4 29.9
untitled Ef Smiths Fork
Stateline Reservoir, Robertson,nr 6.1 110 44 5.5 100 5.5 13.9
untitled Green
Flaming Gorge Reservoir 2496.9 81 67 2900.9 94 3081.2 3749.0
untitled Strawberry
Strawberry Reservoir, Soldier Springs 810.1 100 73 829.0 102 811.3 1105.9
Starvation Reservoir, Duchesne, Nr 131.6 94 80 133.7 96 139.7 165.3
untitled Rock Ck
Upper Stillwater Reservoir 9.1 90 29 13.4 132 10.1 31.4
untitled Lake Fork
Moon Lake Reservoir, Mtn Home, Nr 25.5 128 70 23.8 120 19.9 36.5
untitled Big Brush Ck
Red Fleet Reservoir, Vernal, Nr 9.7 55 38 10.6 60 17.7 25.7
untitled Price
Scofield Reservoir, Scofield, Nr 14.4 56 22 17.8 70 25.6 65.8
untitled Seeley Ck
Joes Vly Reservoir, Orangeville, Nr 30.1 78 48 21.5 56 38.5 62.5
untitled Huntington Ck
Electric Lake 10.8 61 34 11.1 63 17.6 31.5
untitled
TOTAL 3728.0 85 66 4164.4 95 4360.8 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