Upper Colorado Water Supply Outlook, January 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-July160 235 107 325
Willow Ck
Willow Ck Res, Granby, Nr April-July26 48 102 82
Fraser
Winter Park April-July14 21 108 28
Williams Fork
Williams Fork Res, Parshall, Nr April-July68 100 104 137
Muddy Ck
Wolford Mountain Reservoir April-July25 55 102 80
Blue
Dillon Res April-July120 173 106 235
Green Mtn Res April-July200 280 102 400
Colorado
Kremmling, Nr April-July590 895 104 1300
Eagle
Gypsum, Blo April-July185 300 90 460
Colorado
Dotsero, Nr April-July900 1400 100 2050
Frying Pan
Ruedi Res, Basalt, Nr April-July85 125 90 185
Roaring Fork
Glenwood Springs April-July450 650 94 900
Colorado
Glenwood Springs, Blo April-July1380 2070 98 3050
Cameo, Nr April-July1500 2310 98 3450
Plateau Ck
Cameo, Nr April-July65 120 97 210
Colorado
Cisco, Nr April-July2900 4370 98 6600
Lake Powell, Glen Cyn Dam, At April-July4000 6810 95 10200


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-July65 97 98 149
Almont April-July110 152 98 250
East
Almont April-July129 182 100 280
Gunnison
Gunnison, Nr April-July240 365 99 600
Tomichi Ck
Gunnison April-July38 68 92 109
Lake Fork
Gateview April-July90 130 106 180
Gunnison
Blue Mesa Res April-July400 660 98 950
Morrow Point Res April-July460 720 97 1010
Crystal Res April-July550 810 97 1100
Muddy Ck
Paonia Res, Bardine, Nr March-June60 100 104 135
April-July57 101 104 146
Nf Gunnison
Somerset, Nr April-July200 300 102 400
Surface Ck
Cedaredge April-July11 16 95 31
Uncompahgre
Ridgway Res April-July66 97 96 139
Colona April-July85 129 94 200
Delta April-July67 105 93 175
Gunnison
Grand Junction, Nr April-July900 1440 97 2050


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-July180 265 108 375
Mcphee Res April-July190 310 105 475
San Miguel
Placerville, Nr April-July85 130 102 190
Dolores
Cisco, Nr April-July350 580 103 960

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 379.6 101 77 282.8 75 375.1 490.3
untitled Willow Ck
Willow Ck Res, Granby, Nr 8.2 107 90 7.8 102 7.6 9.1
untitled Williams Fork
Williams Fork Res, Parshall, Nr 75.0 113 77 43.0 65 66.5 96.9
untitled Muddy Ck
Wolford Mountain Reservoir 43.8 97 66 24.7 55 45.1 66.0
untitled Blue
Dillon Res 241.5 106 95 178.0 78 226.9 254.0
Green Mtn Res 90.4 101 62 64.8 72 89.8 146.9
untitled Homestake Ck
Homestake Res -9999.0 -99 -99 0.2 1 32.9 43.0
untitled Frying Pan
Ruedi Res, Basalt, Nr 83.1 108 81 63.8 83 76.8 102.0
untitled Plateau Ck
Vega Res, Collbran, Nr 14.9 125 45 7.8 65 12.0 32.9
untitled Taylor
Taylor Park Res 71.4 105 67 56.6 83 68.1 106.2
untitled Gunnison
Blue Mesa Res 380.9 69 46 327.5 60 549.9 829.5
Morrow Point Res 107.2 96 92 106.4 95 111.6 117.0
Crystal Res 16.0 104 91 15.8 103 15.4 17.5
untitled Muddy Ck
Paonia Res, Bardine, Nr 0.5 11 3 1.3 30 4.2 16.7
untitled Uncompahgre
Ridgway Res 72.7 106 88 54.3 79 68.8 83.0
untitled Dolores
Mcphee Res 182.4 68 48 192.2 71 270.1 381.1
untitled
TOTAL 1767.4 89 64 1426.9 71 1987.9 2749.1
Colorado
Lake Powell 10323.8 58 42 12712.5 72 17744.8 24322.0
untitled
TOTAL 10323.8 58 42 12712.5 72 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