Prognostic Meteorological Discussion
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FXAK02 KWNH 281629
PMDAK

ALASKA EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1129 AM EST SAT FEB 28 2015

VALID 12Z WED MAR 04 2015 - 12Z SUN MAR 08 2015


THE MESSY SYSTEM LIFTING INTO THE GULF IS NOW IN THE SHORT RANGE,
WITH THE IMPORTANT DECISIONS FROM DAY 4 (WEDNESDAY) ONWARD
DEPENDENT ON THE NATURE OF THE FLOW CROSSING THE BERING SEA AND
THE FORMATION OF A NEW CLOSED VORTEX WELL OFF THE WEST COAST OF
THE LOWER 48 BY THIS TIME NEXT WEEKEND. THE EC CAMP HAS SLOWED
WITH THE PROGRESSION OF THE KAMCHATKA LOW ACROSS THE BERING DAYS 3
AND 4, BUT IS STILL NOT AS SLOW AS THE STEADY NAEFS MEAN. WITH THE
SLOWER TREND EVEN IN THE EC, A HEAVY WEIGHTING OF THE NAEFS DAYS 4
AND 5 SEEMS BEST. THE ECENS MEAN AND CANADIAN MEAN BOTH INDICATE A
CLOSING VORTEX NEAR 40N/140W BY LATE NEXT WEEK, WITH THE GEFS MEAN
LAGGING IN THIS CASE. AS SUCH, TIPPING THE WEIGHT OF THE MEANS IN
THE MANUAL BLEND TO THE ECENS MEAN FOR DAYS 6 THROUGH 8 SIDESTEPS
THE GEFS CONTRIBUTION IN THE NAEFS MEAN. EITHER WAY, THE PEAK OF
THE ACTIVITY OVER THE GULF SHOULD BE DAYS 3 AND 4, WITH A SLOW,
SOUTHEASTWARD SUPPRESSION OF SYSTEM WITH TIME THEREAFTER.


CISCO

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