Lake Powell Water Supply Outlook, June 1, 2014

Note: This publication is scheduled for revision. If you have feedback on content, format, or publication frequency, please contact us.
Prepared by Alcorn
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		50%
Exceedance
Volume		Percent
Average		10%
Exceedance
Volume
Green
Daniel, Nr, Warren Bridge, At April-July310 340 139 380
June-July205 235 140 275
Pine Ck
Fremont Lk, Abv April-July109 119 121 136
June-July80 90 118 107
New Fork
Big Piney, Nr April-July410 455 128 520
June-July270 315 124 380
Green
Fontenelle Res, Fontenelle Nr April-July1010 1130 156 1250
June-July640 755 159 880
Big Sandy
Farson, Nr April-July43 49 94 57
June-July26 32 94 40
Green
Green River, Wy, Nr April-July985 1130 155 1260
June-July630 775 161 905
Hams Fork
Frontier, Nr, Pole Ck, Blo April-July67 72 133 81
June-July23 28 108 37
Viva Naughton Res April-July82 91 123 101
June-July25 34 110 44
Blacks Fork
Robertson, Nr April-July86 94 106 106
June-July40 48 81 60
Ef Smiths Fork
Stateline Res, Robertson,nr April-July25 28 108 32
June-July12 15 84 19
Green
Flaming Gorge Res, Flaming Gorge Dam, At April-July1190 1320 135 1480
June-July730 860 143 1020


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-July31 34 148 40
June-July6 9 105 14.5
Steamboat Springs April-July350 375 144 410
June-July150 176 148 210
Elk
Milner, Nr April-July420 455 142 490
June-July200 235 148 270
Elkhead Ck
Long Gulch, Abv, Hayden, Nr April-July70 77 105 83
June-July6 13 125 19
Yampa
Maybell, Nr April-July1080 1200 128 1280
June-July440 560 144 640
Little Snake
Slater, Nr April-July200 210 135 230
June-July70 80 121 100
Savery, Nr April-July335 375 109 410
June-July105 146 108 180
Lily, Nr April-July330 375 109 420
June-July125 172 128 215
Yampa
Deerlodge Park April-July1400 1550 125 1700
June-July550 700 140 855
White
Meeker, Nr April-July250 275 98 305
June-July105 130 90 160
Watson, Nr April-July255 280 100 315
June-July110 135 97 170


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-July8.1 9.6 46 12.1
June-July2 3.5 39 6
Ashley Ck
Vernal, Nr April-July15.9 19 38 24
June-July4.1 7.2 30 12
West Fork Duchesne
Vat Diversion, Blo April-July13.4 14.6 78 16.4
June-July5 6.2 67 8
Duchesne
Tabiona, Nr April-July82 92 85 103
June-July35 45 75 56
Rock Ck
Upper Stillwater Res April-July62 69 93 80
June-July30 37 79 48
South Fork Rock Ck
Docs Div, Blo April-July4.8 5.5 75 6.3
June-July2.3 3 61 3.8
Rock Ck
Mountain Home, Nr April-July68 75 85 85
June-July35 42 75 52
Currant Ck
Currant Ck Res April-July8.9 10.6 53 12.7
June-July2 3.7 50 5.8
Strawberry
Solider Springs,nr April-July32 36 51 41
June-July4.5 8 33 13
Starvation Res, Duchesne, Nr April-July44 55 49 61
June-July9 20 53 26
Duchesne
Duchesne, Nr, Knight Div, Abv April-July153 166 86 191
June-July72 85 74 110
Lake Fork
Moon Lake Res, Mtn Home, Nr April-July52 58 88 67
June-July29 35 81 44
Yellowstone
Altonah, Nr April-July43 47 77 54
June-July24 28 68 35
Whiterocks
Whiterocks, Nr April-July19.4 23 43 30
June-July9 13 38 20
Uinta
Neola, Nr April-July42 48 65 58
June-July26 32 64 42
Duchesne
Myton April-July198 220 67 265
June-July82 102 59 150
Randlett, Nr April-July197 220 57 265
June-July80 103 49 150


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-July5.4 6.3 41 7.4
June-July0.8 1.7 50 2.8
Fish Ck
Scofield, Nr, Reservoir, Abv April-July15.3 16.8 56 19.4
June-July3.5 5 52 7.6
Price
Scofield Res, Scofield, Nr April-July19.9 22 54 26
June-July4 6.2 46 9.6
Green
Green River, Ut April-July2870 3220 109 3670
June-July1500 1850 119 2300
Huntington Ck
Electric Lake April-July8 9.5 71 11
June-July1 2.5 52 4
Power Plant, Blo April-July28 31 78 35
June-July12 15 76 19
Seeley Ck
Joes Vly Res, Orangeville, Nr April-July45 50 89 56
June-July17 22 69 28
Ferron Ck
Ferron, Nr April-July33 36 95 40
June-July13 16.6 79 20
Muddy Ck
Emery, Nr April-July14.2 15.8 79 18.2
June-July7 8.6 74 11


Upper Colorado Mainstem Specific Site Forecasts (kaf)

Click site name for graph.
Forecast
Period		90%
Exceedance
Volume		50%
Exceedance
Volume		Percent
Average		10%
Exceedance
Volume
Colorado
Lake Granby, Granby, Nr April-July310 340 155 395
June-July195 225 155 280
Willow Ck
Willow Ck Res, Granby, Nr April-July73 79 168 88
June-July22 28 133 37
Fraser
Winter Park April-July26 29 149 32
June-July19 22 155 25
Williams Fork
Williams Fork Res, Parshall, Nr April-July130 145 151 160
June-July80 95 146 110
Muddy Ck
Wolford Mountain Reservoir April-July94 104 193 114
June-July25 35 181 45
Blue
Dillon Res April-July240 265 163 295
June-July160 185 168 215
Green Mtn Res April-July390 435 158 475
June-July255 300 163 340
Colorado
Kremmling, Nr April-July1320 1430 166 1560
June-July730 845 161 970
Eagle
Gypsum, Blo April-July370 415 124 465
June-July200 245 114 295
Colorado
Dotsero, Nr April-July1900 2120 151 2300
June-July1000 1220 145 1400
Frying Pan
Ruedi Res, Basalt, Nr April-July131 155 112 176
June-July75 99 111 120
Roaring Fork
Glenwood Springs April-July640 740 107 840
June-July400 500 110 600
Colorado
Glenwood Springs, Blo April-July2690 2920 138 3190
June-July1500 1730 133 2000
Cameo, Nr April-July2800 3140 133 3500
June-July1500 1840 130 2200
Plateau Ck
Cameo, Nr April-July100 110 89 130
June-July30 40 82 60
Colorado
Cisco, Nr April-July4530 5000 113 5630
June-July2400 2870 123 3500
Lake Powell, Glen Cyn Dam, At April-July6600 7550 105 8450
June-July3550 4500 120 5400


Gunnison Specific Site Forecasts (kaf)

Click site name for graph.
Forecast
Period		90%
Exceedance
Volume		50%
Exceedance
Volume		Percent
Average		10%
Exceedance
Volume
Taylor
Taylor Park Res April-July110 118 119 127
June-July68 76 123 85
Almont April-July177 194 125 205
June-July100 117 124 130
East
Almont April-July215 235 129 250
May-July0 0 0 0
June-July115 135 127 150
Gunnison
Gunnison, Nr April-July435 470 127 495
June-July240 275 128 300
Tomichi Ck
Gunnison April-July88 94 127 103
June-July35 41 111 50
Lake Fork
Gateview April-July130 140 114 155
June-July80 90 111 105
Gunnison
Blue Mesa Res April-July800 860 127 890
June-July430 490 129 520
Morrow Point Res April-July870 930 126 960
June-July460 520 128 550
Crystal Res April-July970 1030 123 1060
June-July520 580 129 610
Muddy Ck
Paonia Res, Bardine, Nr March-June66 68 71 75
April-July66 68 70 74
June-June13 15 65 22
June-July16.5 18.5 64 26
Nf Gunnison
Somerset, Nr April-July270 285 97 305
June-July105 120 105 140
Surface Ck
Cedaredge April-July12.4 12.8 76 15.4
June-July4 4.4 58 7
Uncompahgre
Ridgway Res April-July86 94 93 104
June-July52 60 92 70
Colona April-July107 114 83 134
June-July65 72 89 92
Delta April-July78 85 75 97
June-July42 49 86 61
Gunnison
Grand Junction, Nr April-July1490 1570 106 1640
June-July750 830 119 900


Dolores Specific Site Forecasts (kaf)

Click site name for graph.
Forecast
Period		90%
Exceedance
Volume		50%
Exceedance
Volume		Percent
Average		10%
Exceedance
Volume
Dolores
Dolores April-July161 178 73 190
June-July48 65 71 77
Mcphee Res April-July170 190 64 205
June-July50 70 72 85
San Miguel
Placerville, Nr April-July115 122 95 130
June-July68 75 100 83
Dolores
Cisco, Nr April-July315 355 63 385
June-July110 150 82 180


San Juan Specific Site Forecasts (kaf)

Click site name for graph.
Forecast
Period		90%
Exceedance
Volume		50%
Exceedance
Volume		Percent
Average		10%
Exceedance
Volume
San Juan
Pagosa Springs April-July134 139 65 145
June-July35 40 42 46
Carracas, Nr April-July205 220 58 230
June-July65 80 51 88
Navajo Res, Archuleta, Nr April-July430 455 62 495
June-July131 156 54 196
Farmington April-July720 760 69 795
June-July260 300 64 335
Bluff, Nr April-July650 695 63 735
June-July240 285 63 325
Rio Blanco
Pagosa Springs, Nr, Blanco Dam, Blo April-July30 33 61 36
June-July7 10 43 13
Navajo
Chromo, Nr, Oso Div Dam, Blo April-July32 36 55 39
June-July12 16 53 19
Piedra
Arboles, Nr April-July134 143 68 152
June-July36 45 61 54
Los Pinos
Vallecito Res, Bayfield, Nr April-July160 169 87 188
June-July72 81 82 100
Animas
Durango April-July345 365 88 405
June-July173 193 88 235
Florida
Lemon Res, Durango, Nr April-July36 42 76 47
June-July12 18 67 23
La Plata
Hesperus April-July10.9 11.4 50 12.2
June-July3.5 4 47 4.8
Mancos
Mancos, Nr April-July13.4 14.1 45 15.6
June-July4.8 5.5 53 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 186.4 114 54 184.6 113 164.0 344.8
untitled Big Sandy
Big Sandy Res, Farson, Nr 24.3 83 63 22.8 77 29.4 38.3
Blacks Fork
Meeks Cabin 30.4 122 102 18.9 76 24.9 29.9
untitled Ef Smiths Fork
Stateline Res, Robertson,nr 14.2 126 102 11.0 97 11.3 13.9
untitled Green
Flaming Gorge Res, Flaming Gorge Dam, At 3185.0 104 85 3002.6 98 3071.5 3749.0
untitled Strawberry
Solider Springs,nr 870.5 122 79 904.9 126 716.0 1105.9
Starvation Res, Duchesne, Nr 158.3 102 96 158.3 102 154.8 165.3
untitled Rock Ck
Upper Stillwater Res 20.4 130 65 18.7 119 15.7 31.4
untitled Lake Fork
Moon Lake Res, Mtn Home, Nr 30.5 107 83 23.9 83 28.6 36.5
untitled Big Brush Ck
Red Fleet Res, Vernal, Nr 13.6 58 53 17.5 75 23.4 25.7
untitled Price
Scofield Res, Scofield, Nr 26.1 54 40 35.2 73 48.5 65.8
untitled Seeley Ck
Joes Vly Res, Orangeville, Nr 51.4 100 82 39.0 75 51.6 62.5
untitled Huntington Ck
Electric Lake 23.1 97 74 21.7 91 23.8 31.5
untitled
TOTAL 4634.3 106 81 4459.0 102 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 383.2 105 78 272.3 75 363.6 490.3
untitled Willow Ck
Willow Ck Res, Granby, Nr 10.1 113 111 10.0 112 8.9 9.1
untitled Williams Fork
Williams Fork Res, Parshall, Nr 91.9 126 95 71.1 97 73.0 96.9
untitled Muddy Ck
Wolford Mountain Reservoir 68.4 114 104 49.3 82 59.9 66.0
untitled Blue
Dillon Res 202.9 87 80 193.8 83 232.7 254.0
Green Mtn Res 98.6 110 67 95.1 106 89.8 146.9
untitled Homestake Ck
Homestake Res 1.4 6 3 5.0 20 24.8 43.0
untitled Frying Pan
Ruedi Res, Basalt, Nr 81.0 104 79 74.7 96 78.0 102.0
untitled Plateau Ck
Vega Res, Collbran, Nr 34.4 112 105 28.2 92 30.8 32.9
untitled Taylor
Taylor Park Res 74.1 99 70 73.6 99 74.7 106.2
untitled Gunnison
Blue Mesa Res 675.6 117 81 398.5 69 575.3 829.5
Morrow Point Res 111.1 98 95 112.2 99 113.2 117.0
Crystal Res 18.7 112 107 12.6 75 16.7 17.5
untitled Muddy Ck
Paonia Res, Bardine, Nr 14.5 92 87 15.6 99 15.7 16.7
untitled Uncompahgre
Ridgway Res 60.9 86 73 72.8 103 70.7 83.0
untitled Dolores
Mcphee Res 270.0 78 71 215.6 62 347.8 381.1
untitled
TOTAL 2196.9 101 79 1700.3 78 2175.6 2792.1
Colorado
Lake Powell 10764.5 59 44 11696.7 64 18186.3 24322.0
untitled
TOTAL 10764.5 59 44 11696.7 64 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 105.8 143 84 62.7 85 74.0 125.4
untitled San Juan
Navajo Res, Archuleta, Nr 1052.7 77 62 928.4 68 1361.0 1696.0
untitled Florida
Lemon Res, Durango, Nr 24.7 103 62 11.2 46 24.1 39.8
untitled
TOTAL 1183.2 81 64 1002.3 69 1459.0 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