Lake Powell Water Supply Outlook, June 1, 2013

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




* 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 Colorado Mainstem Basin Conditions




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

Gunnison Basin Conditions




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

Dolores Basin Conditions




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

San Juan 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-July124 156 64 186
June-July68 100 60 130
Pine Ck
Fremont Lk, Abv April-July53 62 63 76
June-July30 39 51 53
New Fork
Big Piney, Nr April-July128 160 45 225
June-July68 100 39 165
Green
Fontenelle Res, Fontenelle Nr April-July280 350 48 445
June-July123 190 40 290
Big Sandy
Farson, Nr April-July18.9 28 54 33
June-July4.2 13 38 18.6
Green
Green River, Wy, Nr April-July255 325 45 445
June-July100 172 36 290
Hams Fork
Frontier, Nr, Pole Ck, Blo April-July21 25 46 32
June-July5 9.1 35 15.5
Viva Naughton Res April-July28 33 45 40
June-July4 9.4 30 16.5
Blacks Fork
Robertson, Nr April-July54 66 74 75
June-July24 36 61 45
Ef Smiths Fork
Stateline Res, Robertson,nr April-July16.2 19.9 77 24
June-July6.5 10.2 57 14.5
Green
Flaming Gorge Res, Flaming Gorge Dam, At April-July335 440 45 615
June-July130 235 39 410


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 20 87 22
June-July3.4 6.2 72 8.2
Steamboat Springs April-July170 205 79 235
June-July43 80 67 108
Elk
Milner, Nr April-July210 240 75 275
June-July78 106 67 142
Elkhead Ck
Long Gulch, Abv, Hayden, Nr April-July36 39 53 44
June-July0.31 3.3 32 8.5
Yampa
Maybell, Nr April-July500 620 66 735
June-July113 230 59 345
Little Snake
Slater, Nr April-July90 102 65 120
June-July20 32 48 50
Savery, Nr April-July135 151 44 187
June-July30 46 34 82
Lily, Nr April-July128 150 43 178
June-July30 52 39 80
White
Meeker, Nr April-July140 170 61 205
June-July50 80 56 115
Watson, Nr April-July144 172 61 205
June-July55 83 60 116


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-July8.5 9.9 47 13.3
June-July2.3 3.7 41 7.1
Ashley Ck
Vernal, Nr April-July18 24 48 32
June-July4.6 10 42 18.7
West Fork Duchesne
Vat Diversion, Blo April-July8.5 10.7 58 13.1
June-July2.1 4.3 46 6.7
Duchesne
Tabiona, Nr April-July55 66 61 80
June-July23 34 57 48
Rock Ck
Upper Stillwater Res April-July44 50 68 61
June-July21 27 57 38
South Fork Rock Ck
Docs Div, Blo April-July3.4 3.9 53 5.6
June-July1.9 2.4 49 4.1
Rock Ck
Mountain Home, Nr April-July53 59 67 71
June-July28 34 61 46
Currant Ck
Currant Ck Res April-July6 7.5 38 10.8
June-July0.62 2.1 28 5.4
Strawberry
Solider Springs,nr April-July11.1 12.7 23 19.2
June-July0.8 2.4 15.6 8.9
Starvation Res, Duchesne, Nr April-July27 30 27 43
June-July5 8 21 21
Duchesne
Duchesne, Nr, Knight Div, Abv April-July111 126 65 149
June-July52 67 58 90
Lake Fork
Moon Lake Res, Mtn Home, Nr April-July42 47 71 55
June-July21 26 60 34
Yellowstone
Altonah, Nr April-July36 42 69 53
June-July19.2 25 61 36
Whiterocks
Whiterocks, Nr April-July20 30 56 41
June-July8.7 19 56 29
Uinta
Neola, Nr April-July30 44 59 61
June-July13.5 28 56 45
Duchesne
Myton April-July126 152 46 200
June-July35 61 35 111
Randlett, Nr April-July131 160 42 230
June-July37 66 31 134


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-July2.3 2.8 18.1 3.6
June-July0.15 0.7 21 1.5
Fish Ck
Scofield, Nr, Reservoir, Abv April-July11.9 14 47 17.1
June-July1.3 3.4 35 6.5
Price
Scofield Res, Scofield, Nr April-July15.3 17.6 43 23
June-July1.5 3.8 28 8.8
Green
Green River, Ut April-July1180 1480 50 1860
June-July380 680 44 1060
Huntington Ck
Electric Lake April-July5.1 5.9 44 7.7
June-July0.51 1.3 27 3.1
Power Plant, Blo April-July14.6 19.4 49 24
June-July6.3 11.1 56 15.2
Seeley Ck
Joes Vly Res, Orangeville, Nr April-July24 29 52 37
June-July9 14.2 44 22
Ferron Ck
Ferron, Nr April-July15.1 19.2 51 24
June-July6.1 10.2 49 15.5
Muddy Ck
Emery, Nr April-July7.1 8 40 10.1
June-July3.8 4.7 40 6.8


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-July185 205 93 230
June-July110 130 90 155
Willow Ck
Willow Ck Res, Granby, Nr April-July47 51 109 58
June-July14 18 86 25
Fraser
Winter Park April-July15.2 17.2 89 19.2
June-July11 13 92 15
Williams Fork
Williams Fork Res, Parshall, Nr April-July82 88 92 96
June-July50 56 86 64
Muddy Ck
Wolford Mountain Reservoir April-July38 44 81 46
June-July10 16 83 18
Blue
Dillon Res April-July134 149 91 164
June-July90 105 95 120
Green Mtn Res April-July220 245 89 280
June-July140 165 90 200
Colorado
Kremmling, Nr April-July695 785 91 870
June-July360 450 86 535
Eagle
Gypsum, Blo April-July183 215 64 240
June-July95 125 58 150
Colorado
Dotsero, Nr April-July1050 1170 84 1280
June-July535 650 77 760
Frying Pan
Ruedi Res, Basalt, Nr April-July80 95 68 105
June-July47 62 70 72
Roaring Fork
Glenwood Springs April-July405 465 67 505
June-July250 310 68 350
Colorado
Glenwood Springs, Blo April-July1500 1660 79 1820
June-July800 965 74 1120
Cameo, Nr April-July1550 1740 74 1920
June-July830 1020 72 1200
Plateau Ck
Cameo, Nr April-July53 61 49 71
June-July7 15 31 25
Colorado
Cisco, Nr April-July2260 2570 58 2810
June-July1000 1300 56 1550
Lake Powell, Glen Cyn Dam, At April-July2480 3000 42 3480
June-July1000 1520 40 2000


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-July61 69 70 77
June-July34 42 68 50
Almont April-July87 98 63 106
June-July46 57 61 65
East
Almont April-July102 110 60 118
May-July0 0 0 0
June-July52 60 57 68
Gunnison
Gunnison, Nr April-July185 210 57 235
June-July98 123 57 148
Tomichi Ck
Gunnison April-July16 19 26 23
June-July7 9 24 13
Lake Fork
Gateview April-July63 68 55 73
June-July30 35 43 45
Gunnison
Blue Mesa Res April-July330 370 55 400
June-July154 194 51 225
Morrow Point Res April-July360 400 54 430
June-July165 205 51 235
Crystal Res April-July395 435 52 465
June-July180 220 49 250
Muddy Ck
Paonia Res, Bardine, Nr March-June35 37 39 38
April-July35 37 38 40
June-June7 9 39 10
June-July9.5 11.2 39 14
Nf Gunnison
Somerset, Nr April-July151 169 57 180
June-July52 69 61 80
Surface Ck
Cedaredge April-July4.8 5.4 32 6.9
June-July1.2 1.8 24 3.3
Uncompahgre
Ridgway Res April-July44 51 50 59
June-July19 27 42 35
Colona April-July46 54 39 63
June-July15 23 28 32
Delta April-July33 38 34 44
June-July5 10 17.5 16
Gunnison
Grand Junction, Nr April-July585 650 44 710
June-July190 255 37 315


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-July75 90 37 115
June-July10 27 29 40
Mcphee Res April-July80 95 32 120
June-July10 28 29 45
San Miguel
Placerville, Nr April-July47 65 51 77
June-July15 33 44 45
Dolores
Cisco, Nr April-July127 147 26 190
June-July20 40 22 70


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-July97 106 49 116
June-July20 29 30 39
Carracas, Nr April-July129 136 36 146
June-July43 50 32 60
Navajo Res, Archuleta, Nr April-July265 300 41 340
June-July40 75 26 110
Farmington April-July380 400 36 435
June-July75 93 19.8 126
Bluff, Nr April-July340 365 33 385
June-July56 80 17.8 120
Rio Blanco
Pagosa Springs, Nr, Blanco Dam, Blo April-July22 24 44 27
June-July5.5 7.5 33 10
Navajo
Chromo, Nr, Oso Div Dam, Blo April-July24 26 40 29
June-July7 9 30 12
Piedra
Arboles, Nr April-July105 109 52 115
June-July26 30 41 36
Los Pinos
Vallecito Res, Bayfield, Nr April-July97 105 54 115
June-July32 40 40 50
Animas
Durango April-July178 193 47 210
June-July62 77 35 94
Florida
Lemon Res, Durango, Nr April-July22 25 45 29
June-July5 8 30 12
La Plata
Hesperus April-July6.4 6.9 30 8.4
June-July1 1.5 17.6 2.5
Mancos
Mancos, Nr April-July8.4 9.9 32 11.9
June-July1.5 3 29 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 184.6 113 54 227.3 139 164.0 344.8
untitled Big Sandy
Big Sandy Res, Farson, Nr 22.8 77 59 34.4 117 29.4 38.3
Blacks Fork
Meeks Cabin 19.3 78 65 28.1 113 24.9 29.9
untitled Ef Smiths Fork
Stateline Res, Robertson,nr 11.0 97 79 13.0 115 11.3 13.9
untitled Green
Flaming Gorge Res, Flaming Gorge Dam, At 3002.6 98 80 3107.7 101 3071.5 3749.0
untitled Strawberry
Solider Springs,nr 904.9 115 82 986.9 125 789.3 1105.9
Starvation Res, Duchesne, Nr 158.1 102 96 152.0 98 154.8 165.3
untitled Rock Ck
Upper Stillwater Res 18.8 120 60 20.6 131 15.7 31.4
untitled Lake Fork
Moon Lake Res, Mtn Home, Nr 23.9 83 65 27.2 95 28.6 36.5
untitled Big Brush Ck
Red Fleet Res, Vernal, Nr 17.5 75 68 23.5 100 23.4 25.7
untitled Price
Scofield Res, Scofield, Nr 35.2 73 54 50.8 105 48.5 65.8
untitled Seeley Ck
Joes Vly Res, Orangeville, Nr 39.0 75 62 55.8 108 51.6 62.5
untitled Huntington Ck
Electric Lake 21.7 91 69 25.6 108 23.8 31.5
untitled
TOTAL 4459.3 101 78 4752.7 107 4436.9 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 272.3 75 56 426.1 117 363.6 490.3
untitled Willow Ck
Willow Ck Res, Granby, Nr 10.0 112 109 8.2 93 8.9 9.1
untitled Williams Fork
Williams Fork Res, Parshall, Nr 71.1 97 73 91.9 126 73.0 96.9
untitled Muddy Ck
Wolford Mountain Reservoir 49.3 82 75 66.1 110 59.9 66.0
untitled Blue
Dillon Res 193.8 83 76 243.2 105 232.7 254.0
Green Mtn Res 95.1 106 65 102.4 114 89.8 146.9
untitled Homestake Ck
Homestake Res 5.0 20 12 0.3 1 24.8 43.0
untitled Frying Pan
Ruedi Res, Basalt, Nr 74.7 96 73 85.2 109 78.0 102.0
untitled Plateau Ck
Vega Res, Collbran, Nr 28.2 92 86 30.6 99 30.8 32.9
untitled Taylor
Taylor Park Res 73.6 99 69 80.5 108 74.7 106.2
untitled Gunnison
Blue Mesa Res 398.5 69 48 526.7 92 575.3 829.5
Morrow Point Res 112.2 99 96 112.3 99 113.2 117.0
Crystal Res 12.6 75 72 14.9 89 16.7 17.5
untitled Muddy Ck
Paonia Res, Bardine, Nr 15.6 99 93 15.4 99 15.7 16.7
untitled Uncompahgre
Ridgway Res 72.8 103 88 75.1 106 70.7 83.0
untitled Dolores
Mcphee Res 215.6 62 57 338.2 97 347.8 381.1
untitled
TOTAL 1700.3 78 61 2217.2 102 2175.6 2792.1
Colorado
Lake Powell 11696.7 64 48 15631.9 86 18186.3 24322.0
untitled
TOTAL 11696.7 64 48 15631.9 86 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 80.3 80 64 123.7 123 100.5 125.4
untitled San Juan
Navajo Res, Archuleta, Nr 990.1 69 58 1302.7 91 1429.7 1696.0
untitled Florida
Lemon Res, Durango, Nr 14.4 45 36 31.6 98 32.1 39.8
untitled
TOTAL 1084.8 69 58 1458.0 93 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