Lake Powell Water Supply Outlook, June 1, 2016

Note: This publication is scheduled for revision. If you have feedback on content, format, or publication frequency, please contact us.
Prepared by CBRFC
NOAA, National Weather Service
Colorado Basin River Forecast Center
Salt Lake City, Utah
www.cbrfc.noaa.gov

Contents

Lake Powell Sub-Basin Summaries




*Median of forecasts within each basin.





*Median of forecasts within each basin.







*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 Colorado Mainstem Basin Conditions




Snow Water Equivalent in Percent of Median.
* Percent usable capacity, not percent average contents.
Click for multi-month Graph.

Gunnison Basin Conditions




Snow Water Equivalent in Percent of Median.
* Percent usable capacity, not percent average contents.
Click for multi-month Graph.

Dolores Basin Conditions




Snow Water Equivalent in Percent of Median.
* Percent usable capacity, not percent average contents.
Click for multi-month Graph.

San Juan 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-July172 180 192 78 199 215
June-July105 113 125 74 132 150
Pine Ck
Fremont Lk, Abv April-July71 77 85 87 90 97
June-July50 56 64 84 69 76
New Fork
Big Piney, Nr April-July245 255 285 80 310 335
June-July155 167 195 76 220 245
Green
Fontenelle Res, Fontenelle Nr April-July575 600 650 90 695 745
June-July300 325 375 79 420 470
Big Sandy
Farson, Nr April-July41 45 49 94 51 56
June-July24 28 32 94 34 39
Green
Green River, Wy, Nr April-July610 640 675 92 730 795
June-July310 340 375 78 430 495
Hams Fork
Frontier, Nr, Pole Ck, Blo April-July50 52 54 100 57 62
June-July12.1 13.9 16.2 62 18.4 24
Viva Naughton Res April-July63 65 68 92 70 78
June-July14.1 16 18.5 60 21 29
Blacks Fork
Robertson, Nr April-July93 99 103 116 106 114
June-July61 67 71 120 74 82
Ef Smiths Fork
Stateline Res, Robertson,nr April-July29 32 33 127 36 37
June-July18.5 21 22 124 25 26
Green
Flaming Gorge Res, Flaming Gorge Dam, At April-July945 990 1060 108 1130 1190
June-July445 490 560 93 625 685


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-July26 28 28 122 28 29
June-July7 8.1 8.2 95 8.7 9.2
Steamboat Springs April-July310 335 340 131 345 365
June-July130 155 160 134 165 185
Elk
Milner, Nr April-July390 420 425 133 430 455
June-July180 210 215 135 220 245
Elkhead Ck
Long Gulch, Abv, Hayden, Nr April-July90 93 93 127 94 97
June-July11.8 14.2 14.9 143 16 18.1
Yampa
Maybell, Nr April-July1100 1160 1180 126 1190 1270
June-July440 500 520 133 530 605
Little Snake
Slater, Nr April-July183 197 205 131 205 220
June-July70 84 90 136 94 106
Dixon, Nr April-July390 425 435 126 445 470
June-July135 170 180 133 192 215
Lily, Nr April-July410 450 460 133 470 495
June-July145 186 196 146 205 230
Yampa
Deerlodge Park April-July1500 1620 1650 133 1670 1770
June-July580 695 725 145 745 850
White
Meeker, Nr April-July245 255 260 93 260 280
June-July115 127 130 90 133 151
Watson, Nr April-July260 275 280 100 285 305
June-July120 137 140 101 143 163


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-July22 23 24 114 25 27
June-July7.8 8.6 9.5 106 10.1 12.9
Ashley Ck
Vernal, Nr April-July43 46 47 94 48 51
June-July19.2 22 23 96 24 27
West Fork Duchesne
Vat Diversion, Blo April-July14.9 15.3 15.9 85 16.4 17
June-July6.5 6.9 7.5 81 8 8.6
Duchesne
Tabiona, Nr April-July85 89 91 84 95 99
June-July45 49 51 85 55 59
Rock Ck
Upper Stillwater Res April-July63 69 71 96 72 78
June-July41 47 49 104 50 56
South Fork Rock Ck
Docs Div, Blo April-July5.9 6.2 6.6 90 6.8 7.1
June-July3.8 4.1 4.5 92 4.7 5
Rock Ck
Mountain Home, Nr April-July75 81 84 95 85 92
June-July49 55 58 104 59 66
Currant Ck
Currant Ck Res April-July8.5 9.3 9.3 47 9.3 10.6
June-July2.7 3.5 3.5 47 3.5 4.8
Strawberry
Solider Springs,nr April-July30 32 32 45 32 34
June-July6 7.5 7.5 31 7.5 10
Starvation Res, Duchesne, Nr April-July43 47 47 42 47 50
June-July10.7 14.3 14.3 38 14.7 17
Duchesne
Duchesne, Nr, Knight Div, Abv April-July151 160 173 89 179 190
June-July85 94 107 93 113 124
Lake Fork
Moon Lake Res, Mtn Home, Nr April-July50 56 58 88 60 64
June-July33 39 41 95 43 47
Yellowstone
Altonah, Nr April-July53 56 59 97 60 67
June-July37 40 43 105 44 51
Whiterocks
Whiterocks, Nr April-July45 49 50 93 52 55
June-July31 35 36 106 38 41
Uinta
Neola, Nr April-July62 65 69 93 71 77
June-July46 49 53 106 55 61
Duchesne
Myton April-July193 220 225 68 240 255
June-July96 121 130 75 141 159
Randlett, Nr April-July200 245 255 66 270 295
June-July96 139 150 71 164 187


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-July5.6 5.6 5.9 38 6 6.2
June-July0.75 0.8 1.1 32 1.1 1.4
Fish Ck
Scofield, Nr, Reservoir, Abv April-July16.9 17.5 17.7 59 18 19.6
June-July3.9 4.5 4.7 48 5 6.6
Price
Scofield Res, Scofield, Nr April-July20 21 21 51 21 23
June-July3.8 4.3 4.5 34 4.9 6.7
Green
Green River, Ut April-July2890 3060 3190 108 3320 3640
June-July1300 1470 1600 103 1730 2050
Huntington Ck
Electric Lake April-July7.8 8.8 9 68 9.3 10.5
June-July1.8 2.8 3 63 3.3 4.5
Power Plant, Blo April-July28 29 29 73 31 33
June-July15.4 15.8 16.5 83 17.7 20
Seeley Ck
Joes Vly Res, Orangeville, Nr April-July33 34 35 63 36 39
June-July17.5 18.3 20 63 21 24
Ferron Ck
Ferron, Nr April-July26 27 28 74 29 32
June-July14 15.4 16 76 16.6 20
Muddy Ck
Emery, Nr April-July11.1 11.4 12.1 61 12.4 13.7
June-July6 6.3 7 60 7.3 8.6


Upper Colorado Mainstem 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
Colorado
Lake Granby, Granby, Nr April-July185 200 210 95 225 235
June-July113 128 140 97 153 163
Willow Ck
Willow Ck Res, Granby, Nr April-July47 50 54 115 57 60
June-July13.5 16.5 21 100 24 27
Fraser
Winter Park April-July18.5 20 21 108 22 24
June-July14.3 15.8 17 120 17.8 19.8
Williams Fork
Williams Fork Res, Parshall, Nr April-July93 98 102 106 105 115
June-July57 62 66 102 69 79
Muddy Ck
Wolford Mountain Reservoir April-July52 55 58 107 62 70
June-July15.7 18.7 22 114 26 34
Blue
Dillon Res April-July150 160 170 104 175 185
June-July110 120 130 118 135 145
Green Mtn Res April-July240 260 275 100 290 315
June-July163 183 198 108 215 240
Colorado
Kremmling, Nr April-July830 855 900 105 945 1000
June-July470 495 540 103 585 640
Eagle
Gypsum, Blo April-July275 300 315 94 330 350
June-July170 195 210 98 225 245
Colorado
Dotsero, Nr April-July1270 1340 1400 100 1470 1550
June-July725 795 855 102 925 1010
Frying Pan
Ruedi Res, Basalt, Nr April-July105 115 125 90 130 140
June-July72 82 92 103 97 107
Roaring Fork
Glenwood Springs April-July525 560 595 86 615 650
June-July350 385 420 92 440 475
Colorado
Glenwood Springs, Blo April-July1830 1940 2020 96 2080 2200
June-July1090 1200 1280 98 1340 1460
Cameo, Nr April-July1980 2110 2220 94 2320 2450
June-July1160 1290 1400 99 1500 1630
Plateau Ck
Cameo, Nr April-July110 115 125 101 130 145
June-July32 37 47 96 52 67
Colorado
Cisco, Nr April-July3550 3750 3900 88 4050 4250
June-July1800 2000 2150 92 2300 2500
Lake Powell, Glen Cyn Dam, At April-July5800 6100 6500 91 6800 7250
June-July2690 2990 3390 90 3690 4140


Gunnison 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
Taylor
Taylor Park Res April-July79 81 83 84 88 90
June-July53 55 57 92 62 64
Almont April-July118 121 123 79 127 130
June-July77 80 82 87 86 89
East
Almont April-July134 138 141 77 144 148
June-July75 79 82 77 85 89
Gunnison
Gunnison, Nr April-July270 275 280 76 285 295
June-July165 170 175 81 180 190
Tomichi Ck
Gunnison April-July61 62 64 86 66 68
June-July27 28 30 81 32 34
Lake Fork
Gateview April-July107 110 113 92 117 123
June-July74 77 80 99 84 90
Gunnison
Blue Mesa Res April-July550 560 580 86 590 615
June-July315 325 345 91 355 380
Morrow Point Res April-July595 605 625 84 635 660
June-July335 345 365 90 375 400
Crystal Res April-July660 670 690 83 700 725
June-July375 385 405 90 415 440
Muddy Ck
Paonia Res, Bardine, Nr March-June71 74 75 78 76 78
April-July69 72 74 76 77 78
June-June12 15 16 70 17.5 19
June-July15 18 20 69 23 24
Nf Gunnison
Somerset, Nr April-July220 225 225 76 230 235
June-July76 81 84 74 88 92
Surface Ck
Cedaredge April-July10.5 11 11.5 68 12 13.5
June-July2 2.5 3 39 3.5 5
Uncompahgre
Ridgway Res April-July86 89 93 92 99 103
June-July58 61 65 100 71 75
Colona April-July116 119 123 90 130 136
June-July70 73 77 95 84 90
Delta April-July98 101 105 93 112 120
June-July45 48 52 91 59 67
Gunnison
Grand Junction, Nr April-July1160 1190 1210 82 1240 1260
June-July530 560 580 83 615 635


Dolores 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
Dolores
Dolores April-July205 210 215 88 220 230
June-July73 78 82 89 88 98
Mcphee Res April-July215 225 230 78 240 250
June-July70 77 84 87 96 105
San Miguel
Placerville, Nr April-July101 105 110 86 114 120
June-July63 67 72 96 76 82
Dolores
Cisco, Nr April-July400 405 415 73 425 440
June-July145 151 160 87 170 185


San Juan 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
San Juan
Pagosa Springs April-July180 184 189 88 194 200
June-July73 77 82 85 87 95
Carracas, Nr April-July280 285 295 78 305 315
June-July115 120 129 82 137 148
Navajo Res, Archuleta, Nr April-July515 525 545 74 585 595
June-July187 196 215 74 255 265
Farmington April-July740 760 785 71 815 845
June-July300 320 345 73 375 405
Bluff, Nr April-July750 765 780 71 815 850
June-July300 315 330 73 365 400
Rio Blanco
Pagosa Springs, Nr, Blanco Dam, Blo April-July40 42 45 83 48 50
June-July16 18 21 91 24 26
Navajo
Chromo, Nr, Oso Div Dam, Blo April-July45 47 50 77 53 56
June-July21 23 26 87 29 32
Piedra
Arboles, Nr April-July158 161 166 79 173 178
June-July52 55 60 81 67 72
Los Pinos
Vallecito Res, Bayfield, Nr April-July159 167 172 89 185 191
June-July74 82 87 88 100 106
Animas
Durango April-July310 320 330 80 365 370
June-July158 166 178 81 215 220
Florida
Lemon Res, Durango, Nr April-July34 36 39 71 42 46
June-July17 19 22 81 25 29
La Plata
Hesperus April-July16.4 16.9 17.4 76 18.4 19.4
June-July7 7.5 8 94 9 10
Mancos
Mancos, Nr April-July26 27 27 87 28 29
June-July9 9.7 10 96 11 12

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 251.9 154 73 297.8 182 164.0 344.8
untitled Big Sandy
Big Sandy Res, Farson, Nr 34.0 116 89 35.0 119 29.4 38.3
Blacks Fork
Meeks Cabin 25.2 101 84 30.3 122 24.9 29.9
untitled Ef Smiths Fork
Stateline Res, Robertson,nr 11.9 106 86 14.0 124 11.3 13.9
untitled Green
Flaming Gorge Res, Flaming Gorge Dam, At 3427.2 112 91 3197.7 104 3071.5 3749.0
untitled Strawberry
Solider Springs,nr 829.0 116 75 849.8 119 716.0 1105.9
Starvation Res, Duchesne, Nr 163.9 106 99 163.5 106 154.8 165.3
untitled Rock Ck
Upper Stillwater Res 6.7 42 21 20.9 133 15.7 31.4
untitled Lake Fork
Moon Lake Res, Mtn Home, Nr 23.6 83 65 32.0 112 28.6 36.5
untitled Big Brush Ck
Red Fleet Res, Vernal, Nr 25.7 110 100 18.3 78 23.4 25.7
untitled Price
Scofield Res, Scofield, Nr 25.8 53 39 18.5 38 48.5 65.8
untitled Seeley Ck
Joes Vly Res, Orangeville, Nr 42.8 83 69 48.8 95 51.6 62.5
untitled Huntington Ck
Electric Lake 21.8 91 69 20.9 88 23.8 31.5
untitled
TOTAL 4889.4 112 86 4747.3 109 4363.6 5700.4


Upper Colorado 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 Colorado
Lake Granby, Granby, Nr 437.3 120 89 505.2 139 363.6 490.3
untitled Willow Ck
Willow Ck Res, Granby, Nr 8.7 97 95 7.4 83 8.9 9.1
untitled Williams Fork
Williams Fork Res, Parshall, Nr 86.1 118 89 86.3 118 73.0 96.9
untitled Muddy Ck
Wolford Mountain Reservoir 67.0 112 102 52.5 88 59.9 66.0
untitled Blue
Dillon Res 235.8 101 93 224.8 97 232.7 254.0
Green Mtn Res 97.0 108 66 111.4 124 89.8 146.9
untitled Homestake Ck
Homestake Res 38.2 154 89 24.7 100 24.8 43.0
untitled Frying Pan
Ruedi Res, Basalt, Nr 76.9 99 75 84.3 108 78.0 102.0
untitled Plateau Ck
Vega Res, Collbran, Nr 34.3 111 104 32.3 105 30.8 32.9
untitled Taylor
Taylor Park Res 76.7 103 72 90.5 121 74.7 106.2
untitled Gunnison
Blue Mesa Res 571.6 99 69 652.8 113 575.3 829.5
Morrow Point Res 99.0 87 85 111.6 99 113.2 117.0
Crystal Res 17.0 102 97 16.7 100 16.7 17.5
untitled Muddy Ck
Paonia Res, Bardine, Nr 7.1 46 43 15.6 100 15.7 16.7
untitled Uncompahgre
Ridgway Res 61.8 87 74 72.3 102 70.7 83.0
untitled Dolores
Mcphee Res 366.5 105 96 264.8 76 347.8 381.1
untitled
TOTAL 2280.8 105 82 2353.5 108 2175.6 2792.1
Colorado
Lake Powell 12123.2 67 50 11491.5 63 18186.3 24322.0
untitled
TOTAL 12123.2 67 50 11491.5 63 18186.3 24322.0


San Juan 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 Los Pinos
Vallecito Res, Bayfield, Nr 120.6 120 96 119.9 119 100.5 125.4
untitled San Juan
Navajo Res, Archuleta, Nr 1549.4 108 91 1266.5 89 1429.7 1696.0
untitled Florida
Lemon Res, Durango, Nr 35.0 109 88 34.2 107 32.1 39.8
untitled
TOTAL 1705.0 109 92 1420.6 91 1562.3 1861.2

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