Prognostic Meteorological Discussion
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FXAK02 KWNH 231956
PMDAK

ALASKA EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
255 PM EST MON JAN 23 2017

VALID 12Z FRI JAN 27 2017 - 12Z TUE JAN 31 2017

THE FORECAST STARTS OFF ON FRI/SAT WITH A LARGE CLOSED UPPER LOW
OVER THE BERING SEA... JUST NORTH AND WEST OF THE ALEUTIANS. THIS
CIRCULATION WILL STEER A RATHER DEEP AND WRAPPED-UP LOW PRESSURE
SYSTEM TOWARD THE SOUTH COAST OF THE STATE. MEANWHILE
DOWNSTREAM... WEST COAST US UPPER RIDGING EXTENDS UP THROUGH
WESTERN CANADA INTO VERY EXTREME NORTHERN TIER OF AK. THE OVERALL
UPPER WEAKNESS OVER THE STATE BEGINS TO FILL ON SUN... AS HEIGHTS
BUILD FROM EITHER THE SHARP RIDGE RETROGRADING TOWARD AK OR
RE-DEVELOPING OVER THE EASTERN PAC AND EXTEND INTO AK MON/TUES.
OVERALL THERE IS SOLID CONSENSUS WITH THE GLOBAL MODELS BUT THE
NEW 12Z GFS APPEARS TO BE EITHER A MAJOR OUTLIER TO THIS SCENARIO
AND DETAILS OR IS A POTENTIAL TREND-SETTER TOWARD A SLIGHTLY
ALTERNATIVE SOLUTION. WPC FEELS A BLEND OF THE 06Z GFS AND 00Z/23
ECMWF AND INCLUSION OF EACH MEAN WITH 00Z NAEFS IS A SOLID WAY TO
GO FOR THE BULK OF THE FORECAST. FOR SENSIBLE WEATHER... THE GEFS
AND ECMWF MEANS SUGGEST INITIALLY 850MB TEMPS BEING 1 TO 1.5
STANDARD DEVIATIONS ABOVE AVG THROUGH MOST OF THE WEEKEND BUT THEN
COOL OFF TO NEAR AVG BY THE END OF THE FCST PERIOD. ALSO... VERY
WET CONDITIONS ARE LIKELY FOR THE SOUTHERN COAST AND PANHANDLE
REGION AND PERHAPS THE ALEUTIAN CHAIN/SWRN AK... AS A VERY STRONG
CYCLONE REACHES EASTERN RUSSIA/WESTERN BERING SEA AT THE END OF
THE FCST PERIOD AND LARGE SCALE UPPER DIFLUENT FLOW WITH ONSHORE
FLOW DEVELOPS ACROSS THE STATE.

MUSHER

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