Hydro-Met Discussion - APRFC

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HYDROMETEOROLOGICAL DISCUSSION
NWS ALASKA PACIFIC RIVER FORECAST CENTER ANCHORAGE AK
300 PM AKDT FRI MAY 24 2013

...FLOOD POTENTIAL... 

SEE THE BREAKUP MAP AND THE BREAKUP SUMMARY FOR CURRENT BREAKUP 
ACTIVITY... INCLUDING FLOOD WATCHES AND WARNINGS. 

INCREASED SNOWMELT DUE TO WARMING TEMPERATURES OVER THE NEXT SEVERAL 
DAYS WILL LEAD TO SIGNIFICANT RISES ON STREAMS IN THE EASTERN 
INTERIOR... SOUTHCENTRAL ALASKA...AND COPPER RIVER BASIN.

...HYDROMETEOROLOGICAL DISCUSSION...

A WEAKENING UPPER LEVEL TROUGH REMAINS OVER THE BERING SEA WHILE 
HIGH PRESSURE STRENGTHENS OVER NORTHWEST CANADA.  THE RIDGE WILL 
GRADUALLY EXPAND WESTWARD OVER ALASKA THIS WEEKEND.  THIS WILL BRING 
WARMING TEMPERATURES AND GENERALLY DRY WEATHER TO THE MAINLAND 
THROUGH THE WEEKEND.
 
AT 4AM... FREEZING LEVELS WERE NEAR THE SURFACE OVER THE FAR 
NORTHWEST MAINLAND... RISING TO BETWEEN 3800 AND 5400 FEET OVER MOST 
OF THE MAINLAND... AND THEN TO 7400-8400 FEET OVER THE PANHANDLE.

SELECTION OF PRECIPITATION TOTALS FOR 24 HOURS ENDING AT 4AM: 

LOCATION NAME                 PE TS    24 HR                   
======== ====                 == ==                             
MOGA2    MOTHER GOOSE LAKE    PC RG :  0.17
GKGA2    GULKANA GLACIER      PC RG :  0.17
SNIA2    SNIPE LAKE           PC RG :  0.16

...FORECAST PRECIPITATION... 

LIGHT PRECIPITATION IS POSSIBLE OVER SOUTHERN SOUTHEAST ALASKA 
TODAY.  FOR SATURDAY... LIGHT PRECIPITATION IS EXPECTED OVER 
SOUTHEAST ALASKA.

...QUANTITATIVE PRECIPITATION FORECASTS (QPF) GRIDS... 

DAY 1-3 QPF GRIDS WERE BASED ON A BLEND OF THE NAM AND GFS... WITH 
SOME MANUAL EDITS.  DAY 4-7 QPF GRIDS WERE BASED ON THE GFS... WITH 
OCCASIONAL MANUAL EDITS. 

...LONG RANGE...
THE 6 TO 10 DAY TEMPERATURE OUTLOOK HAS INCREASED CHANCES OF ABOVE 
NORMAL TEMPERATURES OVER ALL OF THE MAINLAND AND THE PANHANDLE.
 
THE 6 TO 10 DAY PRECIPITATION OUTLOOK HAS INCREASED CHANCES OF BELOW 
NORMAL PRECIPITATION OVER MOST OF THE SOUTHERN MAINLAND.
....................................................................

THE HYDROMET DISCUSSION WILL BE ISSUED EVERY DAY UNTIL FREEZE UP 
BEGINS IN THE FALL.  A GRAPHICAL VERSION OF THE HYDROMET DISCUSSION 
IS AVAILABLE AT HTTP://APRFC.ARH.NOAA.GOV/PRODUCTS/GHMD.PHP

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ACL