Upper Colorado 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 Brenda Alcorn, Greg Smith
NOAA, National Weather Service
Colorado Basin River Forecast Center
Salt Lake City, Utah
www.cbrfc.noaa.gov

Contents

Water Supply Forecast Discussion
Upper Colorado Mainstem Basin Conditions
Gunnison Basin Conditions
Dolores Basin Conditions
Upper Colorado Mainstem Specific Site Forecasts
Gunnison Specific Site Forecasts
Dolores Specific Site Forecasts
Reservoir Contents
Precipitation Maps
Definitions
Additional Information
Questions or Comments

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-July	310	340	155	395
	June-July	195	225	155	280
Willow Ck
Willow Ck Res, Granby, Nr	April-July	73	79	168	88
	June-July	22	28	133	37
Fraser
Winter Park	April-July	26	29	149	32
	June-July	19	22	155	25
Williams Fork
Williams Fork Res, Parshall, Nr	April-July	130	145	151	160
	June-July	80	95	146	110
Muddy Ck
Wolford Mountain Reservoir	April-July	94	104	193	114
	June-July	25	35	181	45
Blue
Dillon Res	April-July	240	265	163	295
	June-July	160	185	168	215
Green Mtn Res	April-July	390	435	158	475
	June-July	255	300	163	340
Colorado
Kremmling, Nr	April-July	1320	1430	166	1560
	June-July	730	845	161	970
Eagle
Gypsum, Blo	April-July	370	415	124	465
	June-July	200	245	114	295
Colorado
Dotsero, Nr	April-July	1900	2120	151	2300
	June-July	1000	1220	145	1400
Frying Pan
Ruedi Res, Basalt, Nr	April-July	131	155	112	176
	June-July	75	99	111	120
Roaring Fork
Glenwood Springs	April-July	640	740	107	840
	June-July	400	500	110	600
Colorado
Glenwood Springs, Blo	April-July	2690	2920	138	3190
	June-July	1500	1730	133	2000
Cameo, Nr	April-July	2800	3140	133	3500
	June-July	1500	1840	130	2200
Plateau Ck
Cameo, Nr	April-July	100	110	89	130
	June-July	30	40	82	60
Colorado
Cisco, Nr	April-July	4530	5000	113	5630
	June-July	2400	2870	123	3500
Lake Powell, Glen Cyn Dam, At	April-July	6600	7550	105	8450
	June-July	3550	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-July	110	118	119	127
	June-July	68	76	123	85
Almont	April-July	177	194	125	205
	June-July	100	117	124	130
East
Almont	April-July	215	235	129	250
	May-July	0	0	0	0
	June-July	115	135	127	150
Gunnison
Gunnison, Nr	April-July	435	470	127	495
	June-July	240	275	128	300
Tomichi Ck
Gunnison	April-July	88	94	127	103
	June-July	35	41	111	50
Lake Fork
Gateview	April-July	130	140	114	155
	June-July	80	90	111	105
Gunnison
Blue Mesa Res	April-July	800	860	127	890
	June-July	430	490	129	520
Morrow Point Res	April-July	870	930	126	960
	June-July	460	520	128	550
Crystal Res	April-July	970	1030	123	1060
	June-July	520	580	129	610
Muddy Ck
Paonia Res, Bardine, Nr	March-June	66	68	71	75
	April-July	66	68	70	74
	June-June	13	15	65	22
	June-July	16.5	18.5	64	26
Nf Gunnison
Somerset, Nr	April-July	270	285	97	305
	June-July	105	120	105	140
Surface Ck
Cedaredge	April-July	12.4	12.8	76	15.4
	June-July	4	4.4	58	7
Uncompahgre
Ridgway Res	April-July	86	94	93	104
	June-July	52	60	92	70
Colona	April-July	107	114	83	134
	June-July	65	72	89	92
Delta	April-July	78	85	75	97
	June-July	42	49	86	61
Gunnison
Grand Junction, Nr	April-July	1490	1570	106	1640
	June-July	750	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-July	161	178	73	190
	June-July	48	65	71	77
Mcphee Res	April-July	170	190	64	205
	June-July	50	70	72	85
San Miguel
Placerville, Nr	April-July	115	122	95	130
	June-July	68	75	100	83
Dolores
Cisco, Nr	April-July	315	355	63	385
	June-July	110	150	82	180

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	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

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:

Range		Round to
0-1.99		0.01
2.0-19.9		0.1
20-199		1.0
200-999		5.0
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