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HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE SALT LAKE CITY UTAH
WATER SUPPLY SUMMARY
1000 AM MST TUE FEB 9 2010
STATE OF UTAH HYDROLOGIC OUTLOOK
THE PATTERN CONTINUES - DRY FROM RICHFIELD NORTH... WET SOUTH.
SOUTHERN UTAH HAD A COUPLE OF VERY NICE STORMS THAT AUGMENTED
SNOWPACKS IN THE AREA. IN FACT...SOUTHWEST UTAH IS ALREADY WELL
ABOVE SIMILAR ACCUMULATIONS. THE DRY PATTERN CONTINUES IN NORTHERN
UTAH. NORTHERN SNOWPACKS HAVE IMPROVED SOMEWHAT DURING THE MONTH -
THE BEAR RIVER WENT FROM 54% TO 63%. ANY IMPROVEMENT AT THIS POINT
IS A GOOD THING AND HOPEFULLY THAT IMPROVEMENT WILL CONTINUE.
HOWEVER...THE PROBABILITY OF SIGNIFICANT IMPROVEMENT IN NORTHERN
UTAH SNOWPACKS (LIKE GETTING CLOSE TO AVERAGE) CONTINUES TO DECLINE.
THE PROBABILITY OF AT LEAST AVERAGE SNOWPACK BY APRIL 1: BEAR RIVER
- 3%...WEBER RIVER - 8%...PROVO RIVER - 10%...AND THE UINTAS - 13%.
AS SUCH...THE ODDS ARE HEAVILY STACKED FOR CONTINUED BELOW AVERAGE
SNOWPACK IN THE NORTH THIS YEAR. MUCH OF CENTRAL UTAH IS ALSO WELL
BELOW AVERAGE.
JANUARY PRECIPITATION WAS BELOW TO NEAR NORMAL (83% - 100%) IN
NORTHERN UTAH AND NEAR TO MUCH ABOVE NORMAL (105% - 203%) IN THE
SOUTH. THIS BRINGS THE YEAR TO DATE PRECIPITATION TO BELOW NORMAL IN
THE NORTH AND NEAR TO ABOVE AVERAGE IN THE SOUTH.
CURRENT SOIL MOISTURE SATURATION LEVELS IN RUNOFF PRODUCING AREAS
ARE: BEAR - 49%...WEBER - 48%...PROVO - 30%...UINTA BASIN - 17%...
SE UTAH - 32%...SEVIER - 29%...AND SW UTAH - 24%. SOILS ACROSS THE
STATE ARE AS DRY OR DRIER THAN ANYTHING WE HAVE SEEN IN THE PAST 5
YEARS. DRIER SOILS TYPICALLY MEAN LESS RUNOFF FROM SNOWMELT AND THIS
IS BECOMING A MAJOR CONCERN GIVEN THE POOR SNOWPACKS IN NORTHERN
UTAH.
RESERVOIR STORAGE IS CURRENTLY AT 67% OF CAPACITY STATEWIDE COMPARED
TO 59% LAST YEAR. OVERALL...RESERVOIR STORAGE IS IN EXCELLENT
SHAPE...AND SHOULD PROVIDE ADEQUATE CARRYOVER TO PROVIDE FOR WATER
SUPPLY IN THIS YEAR`S EXPECTED BELOW AVERAGE RUNOFF IN THE NORTH.
STREAMFLOW FORECASTS RANGE FROM 47% FOR CENTERVILLE CREEK TO 200% OF
NORMAL ON THE SANTA CLARA RIVER NEAR THE PINE MOUNTAINS. SURFACE
WATER SUPPLY INDICES RANGE FROM 28% ON THE BEAR RIVER TO 83% FOR THE
VIRGIN.
SNOWPACK
FEBRUARY FIRST SNOWPACKS AS MEASURED BY THE NRCS SNOTEL SYSTEM ARE
AS FOLLOWS: BEAR - 63%...WEBER - 69%...PROVO - 74%...UINTAS -
80%...SOUTHEAST UTAH - 92%...SEVIER - 111% AND SOUTHWEST UTAH AT
164%. THE STATEWIDE FIGURE IS 83% OF AVERAGE. WITH FEBRUARY AND
MARCH REMAINING IN THE SNOW ACCUMULATION SEASON...THE RANGE OF
POTENTIAL OUTCOMES IS NARROWING...HOWEVER ANY OUTCOME IS POSSIBLE
DEPENDING ON FUTURE CLIMATIC CONDITIONS. IF BELOW AVERAGE
PRECIPITATION PREVAILS...SNOWPACKS COULD RANGE BETWEEN 43% (BEAR)
AND 55% (SW UTAH) OF AVERAGE. GIVEN MAXIMUM ACCUMULATIONS... APRIL 1
SNOWPACKS COULD RANGE BETWEEN 105% (BEAR)AND 222% (SW UTAH) OF
AVERAGE. WITH NORMAL ACCUMULATIONS...APRIL 1 SNOWPACKS WILL BE
BETWEEN 77% AND 141% OF AVERAGE.
PRECIPITATION
MOUNTAIN PRECIPITATION DURING JANUARY WAS: BEAR - 85%...WEBER -
83%...PROVO - 100%...UINTAS - 95%...SE UTAH - 105%...SEVIER -
113%...SW UTAH - 203% AND THE STATEWIDE FIGURE IS 101% OF AVERAGE.
THIS BRINGS THE SEASONAL ACCUMULATION (OCT-JAN) TO 84% OF AVERAGE
STATEWIDE.
RESERVOIRS
STORAGE IN 41 OF UTAH`S KEY IRRIGATION RESERVOIRS IS AT 67% OF
CAPACITY UP 6% COMPARED TO FEBRUARY OF LAST YEAR. RESERVOIR STORAGE
ON THE WEBER (72%)...PROVO (90%) AND UINTA BASIN (85%) IS
EXCEPTIONALLY GOOD AND WELL AHEAD OF LAST YEAR.
STREAMFLOW
SNOWMELT STREAMFLOWS ARE EXPECTED TO HAVE A WIDE RANGE FROM MUCH
BELOW AVERAGE TO MUCH ABOVE AVERAGE ACROSS THE STATE OF UTAH THIS
YEAR. FORECAST STREAMFLOWS RANGE FROM 47% ON CENTERVILLE CREEK TO
200% ON THE SANTA CLARA RIVER NEAR THE PINE VALLEY MOUNTAINS. MOST
FLOWS NORTH OF RICHFIELD ARE FORECAST TO FLOW AT BELOW AVERAGE
VOLUMES THIS SPRING...WHILE SOUTH OF RICHFIELD ARE FORECAST TO FLOW
AT NORMAL TO ABOVE NORMAL LEVELS.
BRIAN MCINERNEY RANDY JULANDER
SENIOR HYDROLOGIST DATA COLLECTION SUPERVISOR
NATIONAL WEATHER SERVICE NRCS
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