Upper Colorado Water Supply Outlook, March 1, 2014

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

Contents

Upper Colorado Summary




*Median of forecasts within each basin.


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.


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-July240 310 141 395
Willow Ck
Willow Ck Res, Granby, Nr April-July34 59 126 88
Fraser
Winter Park April-July21 28 144 34
Williams Fork
Williams Fork Res, Parshall, Nr April-July105 135 141 175
Muddy Ck
Wolford Mountain Reservoir April-July60 88 163 113
Blue
Dillon Res April-July195 245 150 300
Green Mtn Res April-July305 395 144 500
Colorado
Kremmling, Nr April-July950 1250 145 1600
Eagle
Gypsum, Blo April-July305 415 124 560
Colorado
Dotsero, Nr April-July1500 1920 137 2500
Frying Pan
Ruedi Res, Basalt, Nr April-July120 165 119 220
Roaring Fork
Glenwood Springs April-July570 785 114 1030
Colorado
Glenwood Springs, Blo April-July2150 2710 128 3550
Cameo, Nr April-July2300 2950 125 3950
Plateau Ck
Cameo, Nr April-July65 115 93 175
Colorado
Cisco, Nr April-July4050 5180 117 7200
Lake Powell, Glen Cyn Dam, At April-July6000 8300 116 11100


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-July99 126 127 156
Almont April-July155 200 129 255
East
Almont April-July165 215 118 275
Gunnison
Gunnison, Nr April-July335 465 126 615
Tomichi Ck
Gunnison April-July67 92 124 135
Lake Fork
Gateview April-July115 145 118 186
Gunnison
Blue Mesa Res April-July660 850 126 1140
Morrow Point Res April-July740 930 126 1220
Crystal Res April-July860 1050 126 1340
Muddy Ck
Paonia Res, Bardine, Nr March-June80 105 109 130
April-July81 106 109 131
Nf Gunnison
Somerset, Nr April-July260 310 105 420
Surface Ck
Cedaredge April-July11 16 95 22
Uncompahgre
Ridgway Res April-July76 97 96 133
Colona April-July100 129 94 195
Delta April-July78 105 93 170
Gunnison
Grand Junction, Nr April-July1200 1640 111 2300


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-July170 245 100 325
Mcphee Res April-July190 280 95 385
San Miguel
Placerville, Nr April-July100 135 105 185
Dolores
Cisco, Nr April-July365 520 92 740

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).

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 323.9 98 66 222.2 67 332.0 490.3
untitled Willow Ck
Willow Ck Res, Granby, Nr 9.1 111 100 8.3 101 8.2 9.1
untitled Williams Fork
Williams Fork Res, Parshall, Nr 76.5 123 79 42.1 67 62.4 96.9
untitled Muddy Ck
Wolford Mountain Reservoir 43.6 98 66 23.9 54 44.2 66.0
untitled Blue
Dillon Res 237.2 108 93 166.9 76 219.3 254.0
Green Mtn Res 72.4 98 49 60.6 82 73.5 146.9
untitled Homestake Ck
Homestake Res -9999.0 -99 -99 0.2 1 30.7 43.0
untitled Frying Pan
Ruedi Res, Basalt, Nr 74.5 110 73 62.1 91 67.9 102.0
untitled Plateau Ck
Vega Res, Collbran, Nr 16.5 125 50 8.3 63 13.2 32.9
untitled Taylor
Taylor Park Res 71.6 109 67 56.5 86 65.7 106.2
untitled Gunnison
Blue Mesa Res 398.3 83 48 329.3 68 482.2 829.5
Morrow Point Res 107.7 97 92 104.7 94 111.1 117.0
Crystal Res 14.3 91 81 14.8 94 15.8 17.5
untitled Muddy Ck
Paonia Res, Bardine, Nr 0.7 15 4 1.4 30 4.7 16.7
untitled Uncompahgre
Ridgway Res 75.5 109 91 54.8 79 69.4 83.0
untitled Dolores
Mcphee Res 187.6 69 49 189.0 69 272.3 381.1
untitled
TOTAL 1709.5 93 62 1345.2 72 1842.0 2749.1
Colorado
Lake Powell 9563.1 56 39 11890.9 70 17054.6 24322.0
untitled
TOTAL 9563.1 56 39 11890.9 70 17054.6 24322.0

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: Brenda Alcorn, Greg Smith