Prognostic Meteorological Discussion
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FXAK02 KWNH 292007
PMDAK

ALASKA EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
407 PM EDT SUN MAY 29 2016

VALID 12Z THU JUN 2 2016 - 12Z MON JUN 6 2016

THE PATTERN TO BEGIN THE MONTH OF JUNE WILL BE BLOCKY IN NATURE
WITH A PERSISTENT UPPER HIGH OVER EASTERN RUSSIA AND A RIDGE
BUILDING OVER WESTERN NORTH AMERICA.  BETWEEN THESE TWO AREAS WILL
BE A BROAD UPPER LEVEL TROUGH EXTENDING FROM THE ARCTIC COAST TO
THE GULF OF ALASKA.  AN UPPER LEVEL LOW AND AN ASSOCIATED SURFACE
LOW IS FORECAST TO SLOWLY RETROGRADE WESTWARD ACROSS THE ALEUTIANS
BY THE END OF THE FORECAST PERIOD, WITH MULTIPLE SHORTWAVE
IMPULSES ROTATING AROUND FROM THE BERING SEA ACROSS THE ALEUTIANS
AND INTO THE GULF OF ALASKA.

THE ENSEMBLE GUIDANCE SHOWS REASONABLE AGREEMENT ACROSS THE
FORECAST DOMAIN WITH RESPECT TO THE LARGE SCALE PATTERN WITH
INCREASING UNCERTAINTIES WITH THE PLACEMENT OF SMALLER INDIVIDUAL
FEATURES BY DAY 6 AND BEYOND.  THE 00Z EC MEAN HAD LESS SPREAD
WITH RESPECT TO THE SURFACE PRESSURE PATTERN, PARTICULARLY OVER
THE GULF OF ALASKA.  THE GFS APPEARED TO HAVE A STRONGER SHORTWAVE
MOVING DOWN THE WEST COAST OF ALASKA WHICH APPEARED MORE ROBUST
THAN THE OTHER GUIDANCE.  THE WPC PREFERENCE LEANED MORE IN THE
DIRECTION OF THE ECMWF AND EC MEAN WHICH WAS COORDINATED WITH THE
ANCHORAGE FIELD OFFICE, ALONG WITH SOME OF THE 6Z GEFS MEAN.

IN TERMS OF SENSIBLE WEATHER, MILD WEATHER CAN BE EXPECTED ACROSS
THE INTERIOR WITH HIGHS MAINLY IN THE 60S TO NEAR 70 DEGREES, AND
LOWS IN THE 40S.  IT SHOULD STILL BE COLD ACROSS THE ARCTIC COAST
WITH TEMPERATURES IN THE 30S AND 40S.  THE GREATEST CHANCES FOR
RAINFALL WILL BE ACROSS SOUTHERN ALASKA AND THE SOUTHEAST
PANHANDLE REGION WHICH WILL BE CLOSER TO THE LOW PRESSURE SYSTEM
OVER THE GULF OF ALASKA.

HAMRICK

$$




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