Green Water Supply Outlook, March 1, 2013

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




* Percent usable capacity, not percent average contents.
Click for multi-month Graph.

Yampa/White Basin Conditions




* Percent usable capacity, not percent average contents.
Click for multi-month Graph.

Duchesne Basin Conditions




* Percent usable capacity, not percent average contents.
Click for multi-month Graph.

Lower Green Basin Conditions




* 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-July126 177 72 235
Pine Ck
Fremont Lk, Abv April-July52 75 77 95
New Fork
Big Piney, Nr April-July147 230 65 355
Green
Fontenelle Res, Fontenelle Nr April-July240 435 60 630
Big Sandy
Farson, Nr April-July20 32 62 51
Green
Green River, Wy, Nr April-July230 420 58 625
Hams Fork
Frontier, Nr, Pole Ck, Blo April-July20 33 61 51
Viva Naughton Res April-July28 42 57 69
Blacks Fork
Robertson, Nr April-July35 60 67 95
Ef Smiths Fork
Stateline Res, Robertson,nr April-July11 16.7 64 22
Green
Flaming Gorge Res, Flaming Gorge Dam, At April-July290 550 56 950


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-July8.8 15.4 67 22
Steamboat Springs April-July115 167 64 240
Elk
Milner, Nr April-July144 215 67 305
Elkhead Ck
Long Gulch, Abv, Hayden, Nr April-July20 41 56 60
Yampa
Maybell, Nr April-July340 565 60 890
Little Snake
Slater, Nr April-July54 90 58 133
Savery, Nr April-July95 171 50 265
Lily, Nr April-July92 175 51 275
White
Meeker, Nr April-July110 163 58 240
Watson, Nr April-July100 165 59 265


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-July8.7 13.4 64 23
Ashley Ck
Vernal, Nr April-July19 30 60 53
West Fork Duchesne
Vat Diversion, Blo April-July6.3 12.1 65 16.8
Duchesne
Tabiona, Nr April-July42 69 64 102
Rock Ck
Upper Stillwater Res April-July31 47 64 65
South Fork Rock Ck
Docs Div, Blo April-July2.7 4.6 63 6.5
Rock Ck
Mountain Home, Nr April-July38 57 65 72
Currant Ck
Currant Ck Res April-July5.9 11 55 15.9
Strawberry
Solider Springs,nr April-July16.1 28 51 50
Starvation Res, Duchesne, Nr April-July30 58 52 98
Duchesne
Duchesne, Nr, Knight Div, Abv April-July79 125 64 173
Lake Fork
Moon Lake Res, Mtn Home, Nr April-July26 42 64 55
Yellowstone
Altonah, Nr April-July23 37 61 52
Whiterocks
Whiterocks, Nr April-July21 34 63 52
Uinta
Neola, Nr April-July24 44 59 66
Duchesne
Myton April-July75 162 49 265
Randlett, Nr April-July78 170 44 285


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-July4 9.3 60 15.1
Fish Ck
Scofield, Nr, Reservoir, Abv April-July15.1 21 70 31
Price
Scofield Res, Scofield, Nr April-July20 28 68 43
Green
Green River, Ut April-July990 1580 53 2480
Huntington Ck
Electric Lake April-July5.1 7.5 56 14.2
Power Plant, Blo April-July21 27 68 46
Seeley Ck
Joes Vly Res, Orangeville, Nr April-July19 34 61 53
Ferron Ck
Ferron, Nr April-July11.9 25 66 35
Muddy Ck
Emery, Nr April-July7.1 12.3 62 19.5

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 Res, Fontenelle Nr 141.0 111 41 125.9 99 127.6 344.8
untitled Big Sandy
Big Sandy Res, Farson, Nr 7.9 52 20 22.6 150 15.1 38.3
Blacks Fork
Meeks Cabin 7.6 62 25 17.4 141 12.3 29.9
untitled Ef Smiths Fork
Stateline Res, Robertson,nr 4.7 88 34 7.1 131 5.4 13.9
untitled Green
Flaming Gorge Res, Flaming Gorge Dam, At 2967.3 98 79 3288.8 109 3015.6 3749.0
untitled Strawberry
Solider Springs,nr 896.4 122 81 975.0 132 736.4 1105.9
Starvation Res, Duchesne, Nr 145.0 100 88 162.7 113 144.5 165.3
untitled Rock Ck
Upper Stillwater Res 9.2 121 29 9.9 130 7.6 31.4
untitled Lake Fork
Moon Lake Res, Mtn Home, Nr 10.7 40 29 23.4 88 26.6 36.5
untitled Big Brush Ck
Red Fleet Res, Vernal, Nr 14.3 77 56 22.3 120 18.5 25.7
untitled Price
Scofield Res, Scofield, Nr 30.1 98 46 51.8 169 30.6 65.8
untitled Seeley Ck
Joes Vly Res, Orangeville, Nr 33.7 84 54 48.3 120 40.2 62.5
untitled Huntington Ck
Electric Lake -9999.0 -99 -99 25.1 134 18.8 31.5
untitled
TOTAL 4267.7 102 75 4780.3 114 4180.4 5669.0

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