Upper Colorado Water Supply Outlook, January 1, 2016

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		70%
Exceedance
Volume		50%
Exceedance
Volume		Percent
Average		30%
Exceedance
Volume		10%
Exceedance
Volume
Colorado
Lake Granby, Granby, Nr April-July120 155 197 90 225 280
Willow Ck
Willow Ck Res, Granby, Nr April-July25 40 50 106 55 85
Fraser
Winter Park April-July14 16.5 21 108 23 27
Williams Fork
Williams Fork Res, Parshall, Nr April-July63 76 94 98 104 133
Muddy Ck
Wolford Mountain Reservoir April-July25 40 51 94 65 80
Blue
Dillon Res April-July105 130 152 93 178 215
Green Mtn Res April-July178 220 255 93 290 370
Colorado
Kremmling, Nr April-July520 640 800 93 900 1150
Eagle
Gypsum, Blo April-July195 245 305 91 355 475
Colorado
Dotsero, Nr April-July825 1080 1300 93 1490 1920
Frying Pan
Ruedi Res, Basalt, Nr April-July85 108 125 90 148 195
Roaring Fork
Glenwood Springs April-July450 535 625 91 700 900
Colorado
Glenwood Springs, Blo April-July1300 1630 1950 92 2230 2850
Cameo, Nr April-July1460 1790 2160 92 2450 3200
Plateau Ck
Cameo, Nr April-July80 105 115 93 140 215
Colorado
Cisco, Nr April-July3100 3650 4260 96 5100 6550
Lake Powell, Glen Cyn Dam, At April-July4100 5070 6400 89 7800 9900


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-July65 80 89 90 103 145
Almont April-July100 120 138 89 158 225
East
Almont April-July100 130 145 80 187 245
Gunnison
Gunnison, Nr April-July210 265 305 82 380 530
Tomichi Ck
Gunnison April-July44 67 75 101 85 115
Lake Fork
Gateview April-July90 107 127 103 142 175
Gunnison
Blue Mesa Res April-July430 520 610 90 740 950
Morrow Point Res April-July485 575 665 90 795 1010
Crystal Res April-July575 665 755 90 885 1100
Muddy Ck
Paonia Res, Bardine, Nr March-June60 80 92 96 107 135
April-July61 81 92 95 109 141
Nf Gunnison
Somerset, Nr April-July205 245 285 97 330 395
Surface Ck
Cedaredge April-July11 14.5 17 101 19 28
Uncompahgre
Ridgway Res April-July75 99 108 107 123 150
Colona April-July95 125 140 102 160 200
Delta April-July70 105 115 102 142 190
Gunnison
Grand Junction, Nr April-July1000 1230 1400 95 1780 2020


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-July185 230 285 116 320 400
Mcphee Res April-July220 300 340 115 400 500
San Miguel
Placerville, Nr April-July95 116 142 111 155 195
Dolores
Cisco, Nr April-July420 555 660 117 750 1080

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 468.3 125 96 518.6 138 375.1 490.3
untitled Willow Ck
Willow Ck Res, Granby, Nr 7.9 104 87 8.3 109 7.6 9.1
untitled Williams Fork
Williams Fork Res, Parshall, Nr 79.3 119 82 79.8 120 66.5 96.9
untitled Muddy Ck
Wolford Mountain Reservoir 43.5 97 66 46.1 102 45.1 66.0
untitled Blue
Dillon Res 236.6 104 93 250.9 111 226.9 254.0
Green Mtn Res 70.3 78 48 79.5 88 89.8 146.9
untitled Homestake Ck
Homestake Res -9999.0 -99 -99 -9999.0 -99 32.9 43.0
untitled Frying Pan
Ruedi Res, Basalt, Nr 71.9 94 70 85.0 111 76.8 102.0
untitled Plateau Ck
Vega Res, Collbran, Nr 11.2 94 34 13.9 116 12.0 32.9
untitled Taylor
Taylor Park Res 69.8 103 66 79.4 117 68.1 106.2
untitled Gunnison
Blue Mesa Res 624.5 114 75 574.4 104 549.9 829.5
Morrow Point Res 112.8 101 96 112.0 100 111.6 117.0
Crystal Res 15.3 99 87 15.1 98 15.4 17.5
untitled Muddy Ck
Paonia Res, Bardine, Nr 1.1 25 6 0.7 17 4.2 16.7
untitled Uncompahgre
Ridgway Res 62.6 91 75 76.4 111 68.8 83.0
untitled Dolores
Mcphee Res 243.8 90 64 181.3 67 270.1 381.1
untitled
TOTAL 2118.9 107 77 2121.4 107 1987.9 2749.1
Colorado
Lake Powell 11826.6 67 49 11536.7 65 17744.8 24322.0
untitled
TOTAL 11826.6 67 49 11536.7 65 17744.8 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