Green Water Supply Outlook, April 1, 2016

Note: This publication is scheduled for revision. If you have feedback on content, format, or publication frequency, please contact us.
Prepared by Ashley Nielson
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-July150 170 200 82 215 230
Pine Ck
Fremont Lk, Abv April-July53 67 79 81 86 96
New Fork
Big Piney, Nr April-July146 181 230 65 270 325
Green
Fontenelle Res, Fontenelle Nr April-July380 440 565 78 635 705
Big Sandy
Farson, Nr April-July26 31 37 71 44 53
Green
Green River, Wy, Nr April-July400 450 555 76 640 745
Hams Fork
Frontier, Nr, Pole Ck, Blo April-July27 30 36 67 48 57
Viva Naughton Res April-July36 39 47 64 64 80
Blacks Fork
Robertson, Nr April-July57 65 70 79 81 97
Ef Smiths Fork
Stateline Res, Robertson,nr April-July18 21 23 88 25 29
Green
Flaming Gorge Res, Flaming Gorge Dam, At April-July520 590 740 76 870 1150


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-July17.1 19.8 21 91 23 28
Steamboat Springs April-July210 235 270 104 305 345
Elk
Milner, Nr April-July250 295 315 98 370 390
Elkhead Ck
Long Gulch, Abv, Hayden, Nr April-July43 54 60 82 69 82
Yampa
Maybell, Nr April-July640 780 860 92 970 1050
Little Snake
Slater, Nr April-July87 117 130 83 143 165
Dixon, Nr April-July177 240 270 78 305 380
Lily, Nr April-July176 245 280 81 315 420
Yampa
Deerlodge Park April-July825 1030 1130 91 1290 1450
White
Meeker, Nr April-July190 210 230 82 255 300
Watson, Nr April-July205 225 245 88 265 320


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-July11.6 13.9 16.5 79 18.5 25
Ashley Ck
Vernal, Nr April-July25 31 38 76 42 61
West Fork Duchesne
Vat Diversion, Blo April-July7.3 9 10 54 11.9 14.9
Duchesne
Tabiona, Nr April-July57 64 71 66 76 89
Rock Ck
Upper Stillwater Res April-July48 56 60 81 68 80
South Fork Rock Ck
Docs Div, Blo April-July3.8 4.9 5.2 71 5.6 7
Rock Ck
Mountain Home, Nr April-July57 66 71 81 79 94
Currant Ck
Currant Ck Res April-July7.3 8.5 10.5 53 11.4 14.1
Strawberry
Solider Springs,nr April-July18 22 26 37 30 39
Starvation Res, Duchesne, Nr April-July38 45 51 46 57 70
Duchesne
Duchesne, Nr, Knight Div, Abv April-July115 130 140 72 154 181
Lake Fork
Moon Lake Res, Mtn Home, Nr April-July36 45 50 76 57 63
Yellowstone
Altonah, Nr April-July34 44 48 79 51 61
Whiterocks
Whiterocks, Nr April-July28 35 39 72 44 62
Uinta
Neola, Nr April-July35 48 55 74 60 76
Duchesne
Myton April-July125 163 187 57 210 265
Randlett, Nr April-July140 183 210 55 235 300


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-July4.7 7.7 9.5 61 11.4 13
Fish Ck
Scofield, Nr, Reservoir, Abv April-July12.5 15.1 18 60 21 24
Price
Scofield Res, Scofield, Nr April-July15.9 19.2 23 56 27 31
Green
Green River, Ut April-July1730 2030 2250 76 2770 3200
Huntington Ck
Electric Lake April-July4.6 5.2 6 45 7.2 9.9
Power Plant, Blo April-July18.7 20 22 55 25 32
Seeley Ck
Joes Vly Res, Orangeville, Nr April-July25 31 34 61 37 46
Ferron Ck
Ferron, Nr April-July18.3 23 26 68 29 35
Muddy Ck
Emery, Nr April-July9.4 11.8 13 65 14.1 18.7

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 Res, Fontenelle Nr 139.5 115 40 201.2 165 121.7 344.8
untitled Big Sandy
Big Sandy Res, Farson, Nr 21.9 111 57 24.1 123 19.6 38.3
Blacks Fork
Meeks Cabin 9.5 71 32 26.6 199 13.4 29.9
untitled Ef Smiths Fork
Stateline Res, Robertson,nr 6.6 120 47 10.4 190 5.5 13.9
untitled Green
Flaming Gorge Res, Flaming Gorge Dam, At 3165.0 105 84 3165.7 105 3021.3 3749.0
untitled Strawberry
Solider Springs,nr 801.2 121 72 849.9 128 663.7 1105.9
Starvation Res, Duchesne, Nr 159.5 107 96 164.0 110 149.7 165.3
untitled Rock Ck
Upper Stillwater Res 2.1 48 7 2.5 56 4.5 31.4
untitled Lake Fork
Moon Lake Res, Mtn Home, Nr 24.6 90 67 33.6 123 27.3 36.5
untitled Big Brush Ck
Red Fleet Res, Vernal, Nr 17.4 92 68 12.7 67 19.0 25.7
untitled Price
Scofield Res, Scofield, Nr 13.8 45 21 15.3 50 30.9 65.8
untitled Seeley Ck
Joes Vly Res, Orangeville, Nr 37.2 93 59 41.7 104 40.0 62.5
untitled Huntington Ck
Electric Lake 16.6 91 53 18.4 101 18.3 31.5
untitled
TOTAL 4414.9 107 77 4566.2 110 4134.9 5700.4

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 1981-2010 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: Ashley Nielson