Prognostic Meteorological Discussion
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000
FXAK02 KWNH 301815
PMDAK

ALASKA EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
214 PM EDT SAT MAY 30 2015

VALID 12Z WED JUN 03 2015 - 12Z SUN JUN 07 2015

00Z ENSEMBLES ARGUABLY SHOW BETTER THAN AVERAGE AGREEMENT... BUT
GIVEN THE PAST SEVERAL DAYS OF CHANGES WILL STILL ASSUME THERE IS
MORE TO SHAKE OUT. THE TREND SEEMS TO BE TOWARD A MODEST SYSTEM TO
SLIDE EASTWARD SOUTH OF THE ALEUTIANS AND THE TURN TOWARD THE
AKPEN AND SE BERING SEA NEXT WED-FRI... BEFORE THE PATTERN TURNS
TOWARD INCREASED NW CANADIAN RIDGING AND A CORRESPONDING
RETROGRESSION OF THE UPPER LOW INTO THE BERING -- AT LEAST THAT IS
WHAT THE ENSEMBLES SUGGEST. DOWNSTREAM PATTERN OF INCREASED
TROUGHING IN THE SW CONUS SUPPORTS THIS REX BLOCK IDEA... AND THE
PATTERN OF LATE HAS BEEN ANYTHING BUT ZONAL. NEXT SYSTEM SHOULD
PUSH OUT OF THE CENTRAL PACIFIC INTO THE ALEUTIANS NEXT WEEKEND...
AT A BIT SLOWER PACE THAN PREVIOUSLY FORECAST. GFS RUNS HAVE BEEN
MOSTLY QUICKER THAN THE ECMWF RUNS AS IS OFTEN THE CASE.

USED THE 00Z GEFS AND ECENS MEANS THROUGHOUT THE PERIOD AS AN
AVERAGE OF THE DETERMINISTIC RUNS WOULD BE MOSTLY SIMILAR. 12Z GFS
OFFERS A REASONABLE SOLUTION THROUGH NEXT FRI WITH THE APPROACHING
SYSTEM. TEMPERATURES SHOULD REBOUND BACK TO THE LOW 70S IN THE
INTERIOR LATE IN THE WEEK AFTER A COOL EARLY PART OF THE WEEK IN
THE SHORT RANGE. PRECIPITATION SHOULD FOCUS ALONG SOUTHERN COASTAL
AREAS WITH THE POTENTIAL FOR MODEST AMOUNTS AND ISOLATED HEAVY
AMOUNTS IN EXCESS OF A FEW INCHES. ENSEMBLES SUGGEST A 50/50
PROBABILITY OF EXCEEDING 5 INCHES IN SOME LOCATIONS OVER THE 5-DAY
PERIOD.


FRACASSO

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