Spring Flood Outlook 2009

HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE PUEBLO CO
1045 AM MST FRI FEB 27 2009

...SPRING FLOOD AND WATER RESOURCES OUTLOOK...

THIS OUTLOOK IS FOR THE ARKANSAS RIVER BASIN IN SOUTHEAST COLORADO
AND THE UPPER RIO GRANDE BASIN IN SOUTH CENTRAL COLORADO.

...THE POTENTIAL FOR SPRING FLOODING...FROM SNOWMELT ALONE...IS NEAR
AVERAGE IN THE ARKANSAS BASIN...
...THE POTENTIAL FOR SPRING FLOODING...FROM SNOWMELT ALONE...IS
NEAR AVERAGE IN THE UPPER RIO GRANDE BASIN...

THIS OUTLOOK IS VALID FROM FEBRUARY 27 2009 TO MARCH 13 2009.

...OUTLOOK FOR THE ARKANSAS BASIN...

THE FLOOD POTENTIAL IN THE ARKANSAS BASIN...FROM SNOWMELT ALONE...IS
NEAR AVERAGE. ANY SNOWMELT FLOODING...IF IT WERE TO DEVELOP...WOULD
MOST LIKELY BE MINOR...RESULTING IN MINIMAL OR NO PROPERTY DAMAGE
BUT SOME PUBLIC THREAT OR INCONVENIENCE.

...OUTLOOK FOR THE UPPER RIO GRANDE BASIN...

THE FLOOD POTENTIAL IN THE UPPER RIO GRANDE BASIN...FROM SNOWMELT
ALONE...IS NEAR AVERAGE. ANY SNOWMELT FLOODING...IF IT WERE TO
DEVELOP...WOULD MOST LIKELY BE MINOR...RESULTING IN MINIMAL OR NO
PROPERTY DAMAGE BUT SOME PUBLIC THREAT OR INCONVENIENCE.

THESE FLOOD POTENTIAL ASSESSMENTS ARE BASED ON CURRENT CONDITIONS
AND PROJECTIONS OF AVERAGE TEMPERATURE AND PRECIPITATION FOR THE
COMING MONTHS. IT DOES NOT REFLECT THE FLOOD POTENTIAL SHOULD MORE
EXTREME WEATHER CONDITIONS DEVELOP. IF UNUSUALLY WARM OR WET
WEATHER CONDITIONS DEVELOP OVER THE REGION DURING THE SNOWMELT
RUNOFF PERIOD...THEN MUCH MORE SEVERE FLOODING COULD OCCUR.

...SUMMARY OF PAST...PRESENT AND FUTURE CONDITIONS...

TEMPERATURES HAVE GENERALLY AVERAGED 1 TO 3 DEGREES ABOVE NORMAL
ACROSS THE ARKANSAS BASIN DURING THE WINTER MONTHS. IT HAS BEEN
EVEN MILDER ACROSS THE UPPER RIO GRANDE BASIN WHERE TEMPERATURES
HAVE AVERAGED 3 TO 4 DEGREES ABOVE NORMAL.

IN THE MOUNTAINOUS PORTION OF THE ARKANSAS BASIN...PRECIPITATION HAS
GENERALLY BEEN ABOVE AVERAGE THIS WINTER. HOWEVER...PRECIPITATION
OVER THE PLAINS EAST OF THE MOUNTAINS HAS GENERALLY BEEN BELOW
AVERAGE. ACROSS THE UPPER RIO GRANDE BASIN...MUCH THE SAME PATTERN
HAS BEEN NOTED...WITH ABOVE AVERAGE PRECIPITATION IN THE MOUNTAINS
BUT BELOW AVERAGE PRECIPITATION AT THE LOWER ELEVATIONS.

STREAMFLOW WAS GENERALLY RUNNING NEAR AVERAGE ACROSS BOTH THE
ARKANSAS AND UPPER RIO GRANDE BASINS AT THE END OF FEBRUARY. SOIL
MOISTURE WAS GENERALLY RUNNING NEAR OR BELOW AVERAGE.

MOUNTAIN SNOWPACK WAS RUNNING ABOVE AVERAGE AT THE END OF
FEBRUARY...WITH THE ARKANSAS BASIN REPORTING 118% OF NORMAL
SNOWPACK. THE MOUNTAIN SNOWPACK IN THE UPPER RIO GRANDE BASIN WAS
ALSO RUNNING ABOVE AVERAGE AT 114% OF NORMAL.

OVERALL RESERVOIR STORAGE LEVELS ARE RUNNING SLIGHTLY BELOW AVERAGE.
IN LATE JANUARY...COMBINED STORAGE LEVELS IN THE ARKANSAS BASIN WERE
AROUND 93% OF NORMAL...WHILE COMBINED LEVELS IN THE UPPER RIO GRANDE
BASIN WERE AROUND 82% OF NORMAL.

THE OUTLOOK FOR MARCH...APRIL AND MAY...FROM THE NATIONAL WEATHER
SERVICE CLIMATE PREDICTION CENTER...INDICATES THAT PRECIPITATION
WILL MOST LIKELY BE BELOW AVERAGE ACROSS SOUTHERN COLORADO AND
TEMPERATURES WILL MOST LIKELY BE ABOVE AVERAGE.

THIS LONG RANGE OUTLOOK CONTAINS FORECAST VALUES THAT ARE CALCULATED
USING MULTIPLE SEASON SCENARIOS FROM 50 YEARS OF CLIMATOLOGICAL DATA
INCLUDING CURRENT CONDITIONS OF THE RIVER...SOIL MOISTURE...SNOW
COVER...AND 30 TO 90 DAY LONG RANGE OUTLOOKS OF TEMPERATURE AND
PRECIPITATION. BY PROVIDING THE COMPLETE RANGE OF PROBABILITIES...
THE LEVEL OF RISK ASSOCIATED WITH LONG RANGE PLANNING DECISIONS CAN
BE DETERMINED. THESE FORECASTS ARE PART OF THE NATIONAL WEATHER
SERVICES ADVANCED HYDROLOGIC PREDICTION SERVICE.

THIS IS THE FIRST OF 2 SCHEDULED SPRING FLOOD AND WATER RESOURCES
OUTLOOKS FOR 2009. THE SECOND OUTLOOK IS SCHEDULED TO BE RELEASED
ON FRIDAY...MARCH 13. ADDITIONAL OUTLOOKS MAY BE ISSUED IF
CONDITIONS CHANGE SIGNIFICANTLY. LONG RANGE PROBABILISTIC OUTLOOKS
ARE ISSUED NEAR THE BEGINNING OF THE MONTH THROUGHOUT THE YEAR UNDER
THIS SAME PRODUCT NAME AND HEADING.

VISIT OUR WEB SITE AT WEATHER.GOV/PUEBLO FOR MORE HYDROLOGIC
INFORMATION INCLUDING GRAPHS OF PROBABILISTIC RIVER OUTLOOKS.
YOU CAN LINK TO THE HYDROLOGY PAGE BY CLICKING ON THE LIGHT
BLUE RIVERS AND LAKES TAB NEAR THE TOP OF THE PAGE.


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