Flood Potential Outlook
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FGAK78 PACR 172047
ESFAK

HYDROLOGIC OUTLOOK ... Retransmission
NWS ALASKA PACIFIC RIVER FORECAST CENTER ANCHORAGE AK
9 AM AST THU MAR 16 2017

...SPRING BREAKUP OUTLOOK FOR ALASKA...

THE FLOOD POTENTIAL FROM SNOWMELT AND ICE JAMS THROUGHOUT ALASKA THIS
SPRING IS CURRENTLY RATED AS NORMAL.  THIS WOULD INDICATE THAT
LOCATIONS THAT OFTEN EXPERIENCE FLOODING DURING BREAKUP ARE LIKELY TO
SEE MINOR FLOODING IF AN ICE JAM FORMS DOWNSTREAM. THIS FORECAST IS
BASED ON CURRENT ICE THICKNESS, OBSERVED SNOWPACK, RIVER FREEZE-UP
STAGE, AND LONG RANGE WEATHER FORECASTS.

ICE CONDITIONS

MARCH ICE THICKNESS DATA ARE AVAILABLE FOR A LIMITED NUMBER OF
OBSERVING SITES IN ALASKA. MARCH 1ST MEASUREMENTS INDICATE THAT ICE
THICKNESS IS GENERALLY NORMAL TO SLIGHTLY ABOVE NORMAL ACROSS MOST OF
THE STATE WITH TWO EXCEPTIONS.  THE ICE ON THE YUKON RIVER AT GALENA
WAS SIGNIFICANTLY THICKER THAN NORMAL AND THE ICE THICKNESS MEASURED
ON THE COLVILLE RIVER AT COLVILLE VILLAGE WAS BELOW NORMAL.
ACCUMULATED FREEZING DEGREE DAYS TREND FROM BELOW NORMAL ALONG THE
NORTH SLOPE OF ALASKA TO NEAR NORMAL IN THE INTERIOR OF ALASKA TO
ABOVE NORMAL IN SOUTHCENTRAL AND SOUTHEAST ALASKA.

SNOWPACK

AN ANALYSIS OF THE MARCH 1ST SNOWPACK BY THE NATURAL RESOURCES
CONSERVATION SERVICE (NRCS) INDICATES A GENERALLY BELOW NORMAL
SNOWPACK SOUTH OF THE ALASKA RANGE, INCLUDING SOUTHEAST ALASKA. AREAS
ALONG THE SOUTHERN SLOPES OF THE WESTERN ALASKA RANGE ARE WELL BELOW
AVERAGE.  NORTH OF THE ALASKA RANGE, THERE IS AN AREA OF WELL ABOVE
NORMAL SNOWPACK EAST OF FAIRBANKS, BUT OVERALL AVERAGES WITHIN THE
MIDDLE AND UPPER YUKON BASINS ARE CLOSE TO NORMAL.  SNOWPACK
CONDITIONS ALONG THE DALTON HIGHWAY ON THE NORTH SLOPE OF ALASKA ARE
NEAR NORMAL.   FOR MORE DETAILS, PLEASE REFER TO THE VARIOUS SNOW
GRAPHICS FROM THE ALASKA-PACIFIC RIVER FORECAST CENTER (APRFC) OR
FROM THE NATURAL RESOURCES CONSERVATION SERVICE (NRCS).

CLIMATE OUTLOOK

THE MOST IMPORTANT FACTOR DETERMINING THE SEVERITY OF ICE BREAKUP
REMAINS THE WEATHER DURING APRIL AND MAY. THE TEMPERATURE OUTLOOK FOR
THE NEXT 90-DAYS SUGGESTS AN INCREASED CHANCE OF BELOW NORMAL
TEMPERATURES THROUGH MARCH WITH THE LONGER 90-DAYS OUTLOOK SHOWING
EQUAL CHANCE OF ABOVE OR BELOW NORMAL TEMPERATURES FOR EASTERN ALASKA
AND AN INCREASED CHANCE FOR ABOVE AVERAGE TEMPERATURES IN WESTERN
ALASKA FOR THE THREE MONTHS ENDING IN MAY.  FOR MORE INFORMATION ON
THE CLIMATE FORECASTS PLEASE REFER TO THE CLIMATE PREDICTION CENTER.
THE NEXT SPRING OUTLOOK IS SCHEDULED FOR THURSDAY MARCH 24TH.

$$
bcj/jec



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