Green Water Supply Outlook, March 1, 2015

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		50%
Exceedance
Volume		Percent
Average		10%
Exceedance
Volume
Green
Daniel, Nr, Warren Bridge, At April-July191 250 102 310
Pine Ck
Fremont Lk, Abv April-July67 92 94 112
New Fork
Big Piney, Nr April-July200 300 85 430
Green
Fontenelle Res, Fontenelle Nr April-July490 710 98 935
Big Sandy
Farson, Nr April-July25 36 69 57
Green
Green River, Wy, Nr April-July470 710 97 940
Hams Fork
Frontier, Nr, Pole Ck, Blo April-July30 44 81 65
Viva Naughton Res April-July38 60 81 90
Blacks Fork
Robertson, Nr April-July45 66 74 97
Ef Smiths Fork
Stateline Res, Robertson,nr April-July13.9 20 77 27
Green
Flaming Gorge Res, Flaming Gorge Dam, At April-July540 825 84 1220


Yampa/White Specific Site Forecasts (kaf)

Click site name for graph.
Forecast
Period		90%
Exceedance
Volume		50%
Exceedance
Volume		Percent
Average		10%
Exceedance
Volume
Yampa
Stagecoach Rsvr, Abv April-July17.5 23 100 31
Steamboat Springs April-July170 230 88 320
Elk
Milner, Nr April-July210 280 88 370
Elkhead Ck
Long Gulch, Abv, Hayden, Nr April-July23 43 59 65
Yampa
Maybell, Nr April-July525 725 78 970
Little Snake
Slater, Nr April-July73 115 74 157
Dixon, Nr April-July119 205 59 300
Lily, Nr April-July115 210 61 310
Yampa
Deerlodge Park April-July600 925 75 1300
White
Meeker, Nr April-July175 230 82 320
Watson, Nr April-July180 240 86 340


Duchesne Specific Site Forecasts (kaf)

Click site name for graph.
Forecast
Period		90%
Exceedance
Volume		50%
Exceedance
Volume		Percent
Average		10%
Exceedance
Volume
Big Brush Ck
Vernal, Nr, Red Fleet Res, Abv April-July5.9 11.3 54 19.6
Ashley Ck
Vernal, Nr April-July12.9 23 46 43
West Fork Duchesne
Vat Diversion, Blo April-July5.8 9.5 51 13.7
Duchesne
Tabiona, Nr April-July54 72 67 92
Rock Ck
Upper Stillwater Res April-July42 57 77 73
South Fork Rock Ck
Docs Div, Blo April-July2.9 4.6 63 6.3
Rock Ck
Mountain Home, Nr April-July47 68 77 84
Currant Ck
Currant Ck Res April-July4.2 9.3 47 14
Strawberry
Solider Springs,nr April-July15.5 27 38 48
Starvation Res, Duchesne, Nr April-July30 53 47 83
Duchesne
Duchesne, Nr, Knight Div, Abv April-July100 138 71 170
Lake Fork
Moon Lake Res, Mtn Home, Nr April-July30 47 71 59
Yellowstone
Altonah, Nr April-July32 46 75 60
Whiterocks
Whiterocks, Nr April-July21 32 59 48
Uinta
Neola, Nr April-July26 45 61 65
Duchesne
Myton April-July110 182 55 270
Randlett, Nr April-July118 190 49 295


Lower Green Specific Site Forecasts (kaf)

Click site name for graph.
Forecast
Period		90%
Exceedance
Volume		50%
Exceedance
Volume		Percent
Average		10%
Exceedance
Volume
White
Blo Tabbyune Ck, Soldier Summit, Nr April-July3.2 7.5 48 12.2
Fish Ck
Scofield, Nr, Reservoir, Abv April-July11.9 18 60 27
Price
Scofield Res, Scofield, Nr April-July15.3 24 59 35
Green
Green River, Ut April-July1500 2140 72 3000
Huntington Ck
Electric Lake April-July3.9 6.5 49 11.5
Power Plant, Blo April-July20 26 65 40
Seeley Ck
Joes Vly Res, Orangeville, Nr April-July24 38 68 56
Ferron Ck
Ferron, Nr April-July19 31 82 45
Muddy Ck
Emery, Nr April-July11 15.5 78 24

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 209.8 164 61 136.4 107 127.6 344.8
untitled Big Sandy
Big Sandy Res, Farson, Nr 22.5 149 59 9.7 65 15.1 38.3
Blacks Fork
Meeks Cabin 23.9 194 80 14.4 117 12.3 29.9
untitled Ef Smiths Fork
Stateline Res, Robertson,nr 8.6 161 62 7.1 132 5.4 13.9
untitled Green
Flaming Gorge Res, Flaming Gorge Dam, At 3206.6 106 86 2871.2 95 3015.6 3749.0
untitled Strawberry
Solider Springs,nr 835.6 127 76 832.5 126 660.2 1105.9
Starvation Res, Duchesne, Nr 154.4 107 93 156.3 108 144.5 165.3
untitled Rock Ck
Upper Stillwater Res 14.4 188 46 10.3 135 7.6 31.4
untitled Lake Fork
Moon Lake Res, Mtn Home, Nr 31.9 120 87 24.7 93 26.6 36.5
untitled Big Brush Ck
Red Fleet Res, Vernal, Nr 11.9 64 46 11.3 61 18.5 25.7
untitled Price
Scofield Res, Scofield, Nr 12.4 41 19 15.8 52 30.6 65.8
untitled Seeley Ck
Joes Vly Res, Orangeville, Nr 41.1 102 66 31.2 78 40.2 62.5
untitled Huntington Ck
Electric Lake 18.5 99 59 16.9 90 18.8 31.5
untitled
TOTAL 4591.6 111 81 4137.8 100 4123.0 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