Gale Warning 25, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
205 PM AKST FRI FEB 20 2009

.DISCUSSION...VERY ACTIVE PATTERN FOR THE WEST COAST WITH STRONG
SWRLY JET FLOW DIRECTING LOWS NWRD OVER THE BERING SEA WILL
CONTINUE UNTIL FURTHER NOTICE. 12Z MODELS ALL IN GOOD AGREEMENT
THROUGH 72 HOURS WITH NEXT TWO SYSTEMS.

FIRST SYSTEM IS ABOUT A 980 MB SURFACE LOW NEAR DATELINE/46N
WITH BROAD OCCLUDED FRONT WRAPPED AROUND. MODELS MOVE THIS
LOW NORTH TO CAPE NAVARYN AROUND 18Z SAT WEAKENING IT SLIGHTLY.
FRONT MOVES N AND E OVER BERING COAST AND CHUKCHI SEA COAST SAT
AND SAT NIGHT. UPPER RIDGE HAS AMPLIFIED N AHEAD OF THIS SYSTEM
THOUGH...SO THE FRONT WILL WEAKEN RAPIDLY SAT NIGHT/SUN AS IT
MOVES FURTHER N AND INLAND.

ANOTHER LOW/OCCLUDED FRONT WILL FOLLOW THE FIRST...WTIH SIMILAR
TRAJECTORY SUNDAY INTO MONDAY...THOUGH THIS ONE LOOKS A LITTLE
WEAKER. GFS AND ECMWF START TO DIVERGE WITH NEXT SYSTEM BEHIND
THAT ONE TUE/WED...BUT SOME EFFECT WILL BE FELT ON W COAST.

N SLOPE: MODERATE WRLY SURFACE PRESSURE GRADIENT BETWEEN STRONG
1040+ MB SURFACE HIGH BUILDING IN OVER WRN HALF AK AND 1012 MB
LOW TRACKING E TOWARD BANKS ISLAND SEA WILL GRADUALLY WEAKEN LATE
TONIGHT...THEN REVERSE OVER WRN HALF N SLOPE SAT. BLSN ZONES
203/204 WILL CONTINUE TONIGHT...BUT NOT BAD ENOUGH FOR ADVISORY.

W COAST: WINDS INCREASING TO GALE FORCE AROUND MIDNIGHT OVER
ST LAWRENCE AND MARINE ZONE 210 AS FIRST FRONT APPROACHES. SOLID
GALES THERE THROUGH SAT...AND UPGRADED BLIZZARD WATCH TO WARNING
FOR ZONES 213/214 AS A RESULT. FRONT WILL MOVE OVER NORTON SOUND/
SEWARD PEN. AND CHUKCHI SEA COAST SAT NIGHT/SUN...WEAKENING AS IT
DOES. BUT KEPT WINTER STORM AND BLIZZARD WATCHES FOR ZONES 209
THROUGH 212 GOING...AND ISSUED WATCH FOR 207...ALL FOR SAT NIGHT.
SECOND FRONT WILL BRING SNOW/BLSN TO ST LAWRENCE SUN AFTERNOON
AND REST OF BERING AND CHUKCHI SEA COASTS SUN NIGHT/MON. AT THIS
POINT...IT LOOKS TO BE JUST ADVISORY STRENGTH.

INTERIOR: FAIRLY QUIET NEXT FEW DAYS. UPPER/SURFACE RIDGING
BUILDS IN TONITE...ENDING CURRENT SNOW SHOWER ACTIVITY IN WRLY
FLOW. OVER-RUNNING SNOW FAR ERN INTERIOR WILL TAKE LONGER TO
DIE OUT...AS UPPER TROUGH LINE DOESNT CLEAR ALCAN BORDER UNTIL
ALMOST 12Z SAT. SO ANOTHER INCH OR SO OF SNOW THIS EVENING E OF
PAEG-PABI LINE LIKELY. REMAINS OF FIRST W COAST SYSTEM WILL SLIDE
OVER TOP OF UPPER RIDGE SUN...BUT IT WILL BE WEAKENED SO MUCH BY
THE RIDGE THAT ANY SNOW WOULD LIKELY BE ONLY FROM PABT-PATA WEST.
MODELS SHOW REMAINS OF SECOND W COAST SYSTEM MAY BE SLIGHTLY
STRONGER...WHICH COULD BRING SNOW FURTHER E TUESDAY.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
BLIZZARD WATCH FOR AKZ209-AKZ212-AKZ213-AKZ214.

WINTER WEATHER ADVISORY FOR AKZ204.

WINTER STORM WATCH FOR AKZ210-AKZ211.

GALE WARNING FOR PKZ210.

BRISK WIND ADVISORY FOR PKZ200-PKZ210-PKZ235-PKZ240-PKZ245.
&&

MAR FEB 09