Lower Colorado Water Supply Outlook, February 1, 2016

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.

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

	Forecast Period	90% Exceedance Volume	70% Exceedance Volume	50% Exceedance Volume	Percent Median	30% Exceedance Volume	10% Exceedance Volume
Salt
Roosevelt, Nr	January-May	150	230	370	119	550	770
	February-May	110	191	330	116	510	730
Tonto Ck
Roosevelt, Nr, Gun Ck, Abv	January-May	32	41	58	138	115	240
	February-May	14.6	23	40	114	97	220
Verde
Tangle Ck, Blo, Horseshoe Dam, Abv	January-May	98	135	199	127	365	510
	February-May	64	101	165	121	330	475

	Forecast Period	90% Exceedance Volume	70% Exceedance Volume	50% Exceedance Volume	Percent Median	30% Exceedance Volume	10% Exceedance Volume
Gila
Gila, Nr	January-May	49	67	90	161	130	177
	February-May	37	55	78	156	118	165
Virden, Nr, Blue Ck, Blo	January-May	64	88	118	155	170	240
	February-May	46	70	100	159	152	220
Solomon, Nr, Head Of Safford Vly	January-May	97	142	198	145	285	420
	February-May	69	114	170	138	255	390
San Carlos Res, Coolidge Dam, At	January-May	68	116	150	158	260	445
	February-May	33	81	115	142	225	410
San Francisco
Glenwood, Nr	January-May	15	18.7	26	124	40	55
	February-May	10.7	14.4	22	121	36	51
Clifton	January-May	33	48	67	110	112	164
	February-May	24	39	58	114	103	155

	Forecast Period	90% Exceedance Volume	70% Exceedance Volume	50% Exceedance Volume	Percent Median	30% Exceedance Volume	10% Exceedance Volume
Little Colorado
Lyman Lk, Abv, St. Johns, Nr	January-June	6.2	7.5	8.6	121	14.4	16.6
	February-June	4.5	5.8	6.9	105	12.7	14.9
Zuni
Black Rock Res, Abv	January-May	0.09	0.26	0.57	121	2.4	4.2
	February-May	0.02	0.19	0.5	132	2.3	4.1
Chevelon Ck
Winslow, Nr, Wildcat Cyn, Blo	January-May	6.5	10.8	16.9	122	51	69
	February-May	4.3	8.6	14.7	106	49	67

	EOM Contents	Percent EOM Average	Percent Usable Capacity	Last Year EOM	Last Year %Average	EOM Average	Usable Capacity
Salt
Roosevelt	753.3	84	46	694.4	77	901.4	1653.0
Horse Mesa	224.7	101	92	225.4	101	222.0	245.1
Mormon Flat	54.4	100	94	56.5	104	54.5	57.9
Stewart Mountain	64.4	104	92	64.8	104	62.2	69.8
Horseshoe	63.4	168	58	14.9	40	37.6	109.2
Bartlett	83.7	72	47	99.4	85	116.8	178.2
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TOTAL	1243.9	89	54	1155.4	83	1394.6	2313.2


Bill Williams
Alamo	53.4	37	5	54.2	38	143.3	1045.0
Agua Fria
Lake Pleasant	751.0	117	86	764.9	119	641.6	869.9
Gila
San Carlos	97.2	26	11	84.5	23	366.8	875.0
Colorado
Lake Powell	11426.7	66	47	11146.8	64	17338.2	24322.0
Lake Mead	10318.0	50	40	10729.0	52	20452.4	26120.0
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TOTAL	22646.2	58	43	22779.4	58	38942.2	53231.9

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

Lower Colorado Water Supply Outlook, February 1, 2016

Lower Colorado Summary

Salt Basin Conditions

Gila Basin Conditions

Little Colorado Basin Conditions

Salt Specific Site Forecasts (kaf)

Gila Specific Site Forecasts (kaf)

Little Colorado Specific Site Forecasts (kaf)

Lower Colorado End of Month Reservoir Contents (kaf)

Precipitation Maps

Definitions

Additional Information