Wind Chill Advisory 50, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
230 PM AKST THU JAN 27 2011

.DISCUSSION...
THE GFS AND NAM COMPUTER WEATHER FORECAST MODELS BOTH FORECAST
HIGH PRESSURE ALOFT OVER THE EASTERN GULF OF ALASKA TO BUILD UP
OVER THE YUKON TERRITORY OF CANADA BY SATURDAY. CONTINUED
SOUTHERLY FLOW ALOFT OVER NORTHERN ALASKA WILL CONTINUE TO BRING
TEMPERATURES UP...ESPECIALLY IN THE SOUTHERN INTERIOR...WHERE
AFTERNOON TEMPERATURES ARE EXPECTED TO BE IN THE TEENS AND 20S
STARTING MONDAY.

A 956 MB SURFACE LOW WHICH CROSSED THE ALEUTIANS NEAR 170 DEGREES
WEST LONGITUDE AT NOON IS FORECAST TO MOVE NORTHWESTWARD AND TO
GRADUALLY WEAKEN...BECOMING A 980 MB LOW NEAR ANADYR FRIDAY NIGHT.
FULL GALE FORCE WINDS ARE BLOWING OVER MUCH OF THE WEST COAST OF
ALASKA UP TO BERING STRAIT...THOUGH WINDS IN NORTON SOUND ARE
FORECAST TO BE ONLY 30 KNOTS.

AFTER THIS FIRST LOW WEAKENS OVER SIBERIA SATURDAY AND SATURDAY
NIGHT...THE NEXT PACIFIC LOW PRESSURE SYSTEM / LOW NUMBER 2 / IS
EXPECTED TO MOVE UP OVER THE ALASKA MAINLAND WEST COAST FROM
SUNDAY AFTERNOON TO MONDAY AFTERNOON. THIS LOW IS NOT FORECAST TO
BE ANYWHERE NEAR AS STRONG AS ITS PREDECESSOR. THE WEST PACIFIC
GEOSTATIONARY SATELLITE IMAGERY CONFIRMS THIS. THE INBOUND LOW HAS
BEEN MOVING EASTWARD ABOUT 35 KNOTS AND IS NOW CROSSING THE DATE
LINE NEAR 40 DEGREES NORTH LATITUDE. IT IS NOT BRINGING THE LARGE
SOLID DECK OF CLOUDS OF ITS PREDECESSORS.

FOLLOWING THE PASSAGE OF LOW NUMBER 2...THE GFS FORECASTS A THIRD
LOW PRESSURE SYSTEM TO MOVE NORTHWARD OVER THE ALASKA MAINLAND ON
TUESDAY. THIS SYSTEM IS EXPECTED TO BE WEAKER THAN LOW NUMBER
2...A REASONABLE PREDICTION FOR A LOW MOVING UP OVER THE
WINTERTIME MAINLAND.

THE FORECAST DURATION OF THE SOUTHERLY FLOW ALOFT OVER THE ALASKA
MAINLAND IS QUITE LONG...RUNNING THROUGH ALL OF NEXT WEEK AND
PERHAPS BEYOND. ULTIMATELY...THE ALEUTIAN LOW ALOFT AND THE HIGH
ALOFT OVER WEST CANADA WILL RETROGRADE / MOVE TO THE WEST / AND
THEN COOLER WEATHER CAN BE EXPECTED OVER NORTHERN ALASKA. THIS
CHANGE HAD BEEN FORECAST TO TAKE PLACE EARLIER THAN INDICATED ON
CURRENT FORECASTS.

AFTERNOON POLAR SATELLITE IMAGERY SHOWS A DECK OF STRATOCUMULUS
OVER THE ARCTIC NORTHWEST OF BARROW GRADUALLY ADVANCING TOWARD THE
COAST.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
BLIZZARD WARNING FOR AKZ213.

GALE WARNING FOR PKZ210.

BRISK WIND ADVISORY FOR PKZ200-PKZ215-PKZ220.
&&

TF JAN 11