Lower Colorado Water Supply Outlook, March 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	198	265	335	108	370	445
	March-May	75	143	210	88	245	320
Tonto Ck
Roosevelt, Nr, Gun Ck, Abv	January-May	28	35	45	107	57	110
	March-May	2.7	9.8	20	91	32	85
Verde
Tangle Ck, Blo, Horseshoe Dam, Abv	January-May	95	129	160	102	220	335
	March-May	28	62	93	87	151	270

	Forecast Period	90% Exceedance Volume	70% Exceedance Volume	50% Exceedance Volume	Percent Median	30% Exceedance Volume	10% Exceedance Volume
Gila
Gila, Nr	January-May	52	59	65	116	74	109
	March-May	23	30	36	106	45	80
Virden, Nr, Blue Ck, Blo	January-May	64	73	81	107	91	124
	March-May	28	37	45	105	55	88
Solomon, Nr, Head Of Safford Vly	January-May	106	132	142	104	152	200
	March-May	49	75	85	96	95	145
San Carlos Res, Coolidge Dam, At	January-May	82	102	110	116	132	210
	March-May	19.2	39	47	89	69	148
San Francisco
Glenwood, Nr	January-May	19.8	23	25	119	27	38
	March-May	9.5	12.6	14.7	97	16.3	28
Clifton	January-May	36	48	57	93	58	90
	March-May	15.2	27	36	95	37	69

	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	5.7	6.4	9.1	128	10.5	16.5
	March-June	1.7	2.4	5.1	85	6.5	12.5
Zuni
Black Rock Res, Abv	January-May	0.09	0.14	0.28	60	0.45	2.1
	March-May	0.01	0.06	0.2	87	0.37	2
Chevelon Ck
Winslow, Nr, Wildcat Cyn, Blo	January-May	13.1	16.7	21	151	35	50
	March-May	0.82	4.4	8.3	60	23	38

	EOM Contents	Percent EOM Average	Percent Usable Capacity	Last Year EOM	Last Year %Average	EOM Average	Usable Capacity
Salt
Roosevelt	820.1	86	50	757.7	79	953.2	1653.0
Horse Mesa	224.9	97	92	228.1	99	231.1	245.1
Mormon Flat	55.8	103	96	54.8	101	54.3	57.9
Stewart Mountain	63.7	101	91	62.7	100	63.0	69.8
Horseshoe	77.5	162	71	39.2	82	47.8	109.2
Bartlett	70.6	59	40	87.0	72	120.3	178.2
untitled
TOTAL	1312.6	89	57	1229.5	84	1469.7	2313.2


Bill Williams
Alamo	52.0	33	5	53.3	34	158.3	1045.0
Agua Fria
Lake Pleasant	779.4	106	90	784.9	107	734.3	869.9
Gila
San Carlos	114.0	28	13	134.2	33	404.1	875.0
Colorado
Lake Powell	11224.5	66	46	11023.6	65	17054.6	24322.0
Lake Mead	10360.0	50	40	10769.0	52	20575.4	26120.0
untitled
TOTAL	22529.8	58	42	22765.0	58	38926.8	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, March 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