Prognostic Meteorological Discussion
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FXAK02 KWNH 011850
PMDAK

ALASKA EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
250 PM EDT MON JUN 01 2015

VALID 12Z FRI JUN 05 2015 - 12Z TUE JUN 09 2015

UPPER PATTERN CONTINUES TO POINT TO A COALESCENCE OF THREE SOURCES
OF MID-LEVEL ENERGY INTO THE BERING SEA BY NEXT WEEK. SYNOPTIC
PATTERN IS HANDLED VERY WELL BY THE LESS-DETAILED BUT MORE
SKILLFUL ENSEMBLES BY THE LATTER PART OF THE PERIOD... AS EXPECTED
DETAIL DIFFERENCES PLAGUE THE DETERMINISTIC RUNS. HOWEVER... ANY
RECENT RUN OF THE GFS OR ECMWF FALLS WITHIN THE ENSEMBLE SPREAD
AND CAN BE CONSIDERED A POSSIBLE SOLUTION.

WITH BUILDING RIDGING IN WESTERN CANADA ATOP A RATHER STUCK UPPER
LOW IN THE SW CONUS... ANY LONGWAVE TROUGH TRYING TO PUSH EASTWARD
INTO THE PANHANDLE WILL BE CHALLENGED. THIS SHOULD ALLOW A WAVY
FRONT TO LINGER IN THE NE PAC SOUTH OF THE GULF WITH INCOMING
SHORTWAVE ENERGY MANIFESTING ITSELF AS SURFACE WAVES ALONG THE
BOUNDARY THAT MAY PUSH INTO THE GULF FROM ANYTIME BETWEEN SAT AND
MON NEXT WEEK. THAT BOUNDARY SHOULD WEAKEN/DISSIPATE BY EARLY NEXT
WEEK AS ANOTHER SYSTEM TRAVERSES 50N. THE ENSEMBLES HAVE SLOWED
THIS SYSTEM BY NEARLY A DAY FROM THEIR FORECASTS 24 HOURS AGO...
AND HAVE FOLLOWED SUIT.

PRECIPITATION SIGNAL HAS EASED A BIT FOR SOUTH CENTRAL ALASKA INTO
THE PANHANDLE AS THE FOCUS MEANDERS FROM RUN TO RUN... EVEN IN THE
ENSEMBLES AND THUSLY THE REFORECASTS. HOWEVER... PROLONGED BURSTS
OF HIGH PW AIR INTO THE COAST/PANHANDLE SHOULD YIELD A FEW INCHES
OF RAIN OVER THE PERIOD ESPECIALLY IN LOCALLY FAVORED AREAS IN SW
FLOW.


FRACASSO

$$




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