Heavy Snow Warning 2, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
128 PM AST SUN JAN 21 2007

.DISCUSSION...RAPIDLY WEAKENING SURFACE/UPPER LOW MOVING
N FROM GULF AK INTO AK/YUKON. ASSOCIATED OCCLUDED FRONTAL
SYSTEM ALREADY ALOFT AND N OF AK RANGE WHILE MAIN SURFACE
LOW IS ABOUT 975 MB NEAR PAVD WHILE TRIPLE POINT LOW JUST
BEGINNING TO RE-ORGANIZE OVER YUKON AFTER HURDLING ST. ELIAS
MTNS. OLD VERTICALLY STACKED LOW OVER BRISTOL BAY IS FINALLY
NUDGING E ACROSS AK PEN. AIDED BY SHORT-WAVE DIGGING S OVER
CHUKCHI SEA.

MODELS IN FAIR AGREEMENT THROUGH SHORT AND MID-TERM...AND
12Z GFS IN BASIC AGREEMENT WITH 12Z ECMWF THROUGH 144 HOURS.
GULF AK LOW/REMNANT FRONTAL MOISTURE WILL CONTINUE RAPIDLY
WEAKENING TONIGHT/MON BUT WILL BRING LIGHT SNOW AMOUNTS TO
MOST OF INTERIOR UNDER LIGHT SW FLOW WITH LOW-LEVEL COLD
ADVECTION...AND TROUGH AT 850/700 MB. TREK OF BRISTOL BAY
LOW MON NIGHT/TUE NW INTO GULF AK AND SE INTERIOR WILL ACT
TO FURTHER LOWER HEIGHTS OVER INTERIOR AND PULL EVEN COLDER
AIR EAST...MAINTAINING CLOUDS AND -SN OR FLURRIES OVER
INTERIOR THROUGH THEN. THE DIGGING SHORT-WAVE ALONG W-COAST
TODAY WILL FORM A CLOSED UPPER-LOW OVER SEWARD PEN. MON
THROUGH TUE. THIS WILL MAINTAIN COLD AIR OVER W COAST/WRN
INTERIOR...THOUGH MOISTURE LIMITED AND ONLY FLURRIES LIKELY
THERE NEXT SEVERAL DAYS. SURFACE PRESSURE GRADIENTS BETWEEN
HIGH OVER CHUKOTKA AND BRISTOL BAY LOW WILL WEAKEN TOMORROW
AS THE LOW SHIFTS E. THUS BRISK WIND ADVISORIES MARINE ZONES
210/220/225 WILL END THEN. N SLOPE WILL REMAIN QUIESCENT
NEXT SEVERAL DAYS UNDER LIGHT FLOW ALOFT AND GENERAL LOW-LEVEL
N TO NE FLOW BRINGING JUST FLURRIES OR SOME -SN AIDED BY
REMNANT MOISTURE MOVING N FROM INTERIOR.

BOTH 12Z GFS AND ECMWF SHOW RAPID TRANSITION TO STRONG SRLY
CHINOOK FLOW BEGINNING FRI. THIS COULD BE BEGINNING OF WARMER
MORE ACTIVE PATTERN FOR W COAST STORMS AND AK RANGE CHINOOK
WIND EVENTS BY WEEKS-END.

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
BRISK WIND ADVISORY FOR PKZ210-PKZ220-PKZ225.
&&

MAR JAN 07