Green Water Supply Outlook, May 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-July147 162 179 73 199 210
May-July128 143 160 71 180 193
Pine Ck
Fremont Lk, Abv April-July58 69 76 78 84 97
May-July55 66 73 76 81 94
New Fork
Big Piney, Nr April-July164 210 230 65 275 335
May-July143 191 210 64 255 315
Green
Fontenelle Res, Fontenelle Nr April-July400 470 530 73 605 675
May-July310 380 440 69 515 585
Big Sandy
Farson, Nr April-July31 37 41 79 46 56
May-July28 34 38 79 43 53
Green
Green River, Wy, Nr April-July395 470 525 72 610 705
May-July300 375 430 67 515 610
Hams Fork
Frontier, Nr, Pole Ck, Blo April-July26 30 33 61 38 42
May-July18 22 25 52 30 34
Viva Naughton Res April-July36 40 44 59 50 57
May-July21 25 29 47 35 42
Blacks Fork
Robertson, Nr April-July64 70 75 84 82 92
May-July59 65 70 82 77 87
Ef Smiths Fork
Stateline Res, Robertson,nr April-July22 23 25 96 27 30
May-July21 22 24 92 26 29
Green
Flaming Gorge Res, Flaming Gorge Dam, At April-July615 680 770 79 905 980
May-July475 540 630 75 765 840


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-July18.5 20 21 91 22 26
May-July10.2 12 12.7 79 14 17.3
Steamboat Springs April-July255 280 295 113 305 340
May-July200 225 240 109 250 285
Elk
Milner, Nr April-July305 335 350 109 365 405
May-July255 285 300 103 315 355
Elkhead Ck
Long Gulch, Abv, Hayden, Nr April-July63 69 73 100 76 85
May-July42 48 52 104 55 64
Yampa
Maybell, Nr April-July815 910 950 102 1010 1100
May-July615 710 750 97 810 900
Little Snake
Slater, Nr April-July120 133 144 92 152 174
May-July98 111 122 88 130 152
Dixon, Nr April-July250 280 310 90 330 365
May-July198 225 255 86 275 310
Lily, Nr April-July260 295 325 94 345 390
May-July199 235 265 91 285 330
Yampa
Deerlodge Park April-July1050 1170 1250 101 1300 1500
May-July800 920 1000 98 1050 1250
White
Meeker, Nr April-July200 220 230 82 240 290
May-July165 186 195 80 205 255
Watson, Nr April-July215 235 245 88 255 310
May-July173 195 205 87 215 270


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-July15.3 17.1 18.6 89 19.7 22
May-July12.8 14.6 16.1 88 17.2 20
Ashley Ck
Vernal, Nr April-July36 41 43 86 45 52
May-July33 38 40 85 42 49
West Fork Duchesne
Vat Diversion, Blo April-July8.1 9 10 54 11 12.3
May-July7 7.9 8.9 51 9.9 11.2
Duchesne
Tabiona, Nr April-July61 65 71 66 79 84
May-July52 56 62 63 70 75
Rock Ck
Upper Stillwater Res April-July52 60 64 86 69 76
May-July48 56 60 85 65 72
South Fork Rock Ck
Docs Div, Blo April-July4.4 4.9 5.2 71 5.7 6.3
May-July3.9 4.4 4.7 68 5.2 5.8
Rock Ck
Mountain Home, Nr April-July57 66 71 81 77 85
May-July52 61 66 79 72 80
Currant Ck
Currant Ck Res April-July8.2 9.1 10 50 10.9 11.9
May-July6.5 7.4 8.3 49 9.2 10.2
Strawberry
Solider Springs,nr April-July18.8 21 24 34 28 30
May-July10.7 13 16 28 19.5 22
Starvation Res, Duchesne, Nr April-July33 36 41 37 45 50
May-July22 25 30 33 34 39
Duchesne
Duchesne, Nr, Knight Div, Abv April-July120 129 141 73 153 162
May-July105 114 126 70 138 147
Lake Fork
Moon Lake Res, Mtn Home, Nr April-July40 44 48 73 51 60
May-July37 41 45 71 48 57
Yellowstone
Altonah, Nr April-July41 46 51 84 55 61
May-July37 42 47 82 51 57
Whiterocks
Whiterocks, Nr April-July32 36 41 76 44 52
May-July30 34 39 76 42 50
Uinta
Neola, Nr April-July47 52 59 80 64 77
May-July44 49 56 79 61 74
Duchesne
Myton April-July135 154 173 52 193 220
May-July109 128 147 50 167 196
Randlett, Nr April-July148 169 192 50 215 265
May-July120 141 164 48 187 235


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-July6.7 7.8 8.3 54 9.5 10.9
May-July5.1 6.2 6.7 56 7.9 9.3
Fish Ck
Scofield, Nr, Reservoir, Abv April-July13.3 15.2 16.8 56 18.9 21
May-July10.8 12.7 14.3 55 16.4 18.6
Price
Scofield Res, Scofield, Nr April-July16.3 19.4 21 51 24 27
May-July12.4 15.5 17.4 50 20 23
Green
Green River, Ut April-July1960 2180 2380 80 2600 2980
May-July1580 1800 2000 79 2220 2600
Huntington Ck
Electric Lake April-July4.5 4.9 5.2 39 6.5 7.7
May-July3.3 3.7 4 34 5.3 6.5
Power Plant, Blo April-July18.7 19.4 20 50 24 27
May-July15.4 16.1 17 46 21 24
Seeley Ck
Joes Vly Res, Orangeville, Nr April-July27 30 32 57 34 40
May-July24 27 29 56 31 37
Ferron Ck
Ferron, Nr April-July20 23 25 66 26 30
May-July18.4 21 23 66 24 28
Muddy Ck
Emery, Nr April-July8.8 10.2 11.1 56 11.9 13.8
May-July7.5 8.9 9.8 54 10.6 12.5

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 173.5 139 50 185.1 148 125.0 344.8
untitled Big Sandy
Big Sandy Res, Farson, Nr 24.8 117 65 26.5 124 21.3 38.3
Blacks Fork
Meeks Cabin 14.3 87 48 30.5 185 16.5 29.9
untitled Ef Smiths Fork
Stateline Res, Robertson,nr 7.7 119 56 11.8 182 6.5 13.9
untitled Green
Flaming Gorge Res, Flaming Gorge Dam, At 3213.5 106 86 3212.6 106 3040.4 3749.0
untitled Strawberry
Solider Springs,nr 807.1 119 73 846.0 125 676.1 1105.9
Starvation Res, Duchesne, Nr 164.6 108 100 164.3 108 151.9 165.3
untitled Rock Ck
Upper Stillwater Res 2.2 77 7 6.5 226 2.9 31.4
untitled Lake Fork
Moon Lake Res, Mtn Home, Nr 25.1 91 69 36.2 131 27.6 36.5
untitled Big Brush Ck
Red Fleet Res, Vernal, Nr 18.9 94 74 12.5 62 20.1 25.7
untitled Price
Scofield Res, Scofield, Nr 16.8 51 26 16.3 49 33.0 65.8
untitled Seeley Ck
Joes Vly Res, Orangeville, Nr 36.0 91 58 42.0 106 39.6 62.5
untitled Huntington Ck
Electric Lake 17.4 93 55 18.2 98 18.7 31.5
untitled
TOTAL 4522.1 108 79 4608.5 110 4179.6 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