Winter Storm Warning 26, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
304 AM AKST FRI NOV 13 2009

.DISCUSSION...
COLD TROUGH ALOFT LOCKED IN OVER NORTHERN ALASKA WITH FAST FLOW
ALOFT FROM THE ALASKA PENINSULA ENEWD INTO THE PANHANDLE. TROUGH
WILL BECOME MORE N-S ORIENTED NEXT 24 HOURS BUT REMAIN OVER
MAINLAND ALASKA FOR SOME TIME TO COME.

MODELS NOW IN GOOD AGREEMENT ON DRAMATIC DEEPENING OF A LOW THAT
DEVELOPED OVER BRISTOL BAY THURSDAY IN THE NORTHERN GULF OF ALASKA
TODAY...WITH THE LOW JUMPING THE COASTAL MOUNTAINS AND INTO THE
CENTRAL YUKON BY SATURDAY AFTERNOON. HIGH PRESSURE GRADUALLY
BUILDING OVER THE RUSSIAN FAR EAST THROUGH THE WEEKEND. A 983 MB
LOW WILL DEVELOP IN MACKENZIE BAY LATER TODAY BUT SHOULD MOVE
NORTH AND LARGELY NOT IMPACT NORTHEAST ALASKA.

IN THE MID RANGE...NO CHANGE IN THE FORECAST PHILOSOPHY SINCE YESTERDAY.
THE MODELS AND ENSEMBLES REMAIN IN STELLAR AGREEMENT THAT NORTHERN
AK WILL REMAIN UNDER A DEEP MID/UPPER LEVEL TROUGH THROUGH NEXT
WEEK WITH WELL BELOW AVERAGE HEIGHTS AND THICKNESS VALUES. THE
NCEP RMOP AT 192 THROUGH 240 HOURS CONTINUES TO PAINT ALL OF
MAINLAND AK WITH HIGH MEASURES OF PREDICTABILITY THAT THE AREA
REMAINS UNDER THE UPPER TROUGH. THIS WILL STEER ANY SYSTEMS
THROUGH THE SOUTHERN BERING SEA/ALEUTIANS AND INTO THE GULF AND
WILL SPARE NORTHERN AK FROM ANY MAJOR STORM SYSTEMS. TEMPERATURES
ARE EXPECTED TO BE BELOW AVERAGE...AND AREAS DEVOID OF STRATUS
COULD SEE TEMPS DROP TO NEAR RECORD LOWS.

NORTH SLOPE...AREAS OF LIGHT SNOW PERSISTING INTO THE WEEKEND.
WINDS SHOULD DIMINISH EVEN MORE NEXT 24 HOURS.

FOR THE WEST COAST...SNOW SHOWERS IN ONSHORE FLOW AREAS THRU THE
WEEKEND. WEST OF 160W AT LEAST...NORTH WINDS WILL INCREASE AGAIN
AS PRESSURES RISE OVER CHUKOTKA...WHILE PRESSURE REMAIN LOW OVER
INTERIOR ALASKA UNDER THE UPPER TROUGH.

FOR THE INTERIOR...EXTREMELY HIGH LIQUID TO SNOW AS RESULTED IN
AREAS OF HEAVY SNOW...BUT THIS OUGHT TO BE WINDING DOWN.
HOWEVER...THE DEVELOPING GULF OF ALASKA STORM LOOKS TO HAVE THE
POTENTIAL TO BRING ENOUGH MOISTURE ACROSS THE MOUNTAINS TO
WARRANT A WINTER STORM WATCH FOR HEAVY SNOW STARTING SATURDAY FOR
SOUTHEASTERN INTERIOR AND EASTERN ALASKA RANGE.

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FOR AKZ224-AKZ226.

HEAVY FREEZING SPRAY WARNING FOR PKZ200-PKZ210-PKZ220-PKZ225.

SMALL CRAFT ADVISORY FOR PKZ200-PKZ210-PKZ220-PKZ225.

GALE WARNING FOR PKZ210-PKZ220.

BRISK WIND ADVISORY FOR PKZ230.
&&

RT/CB NOV 09