Blizzard in Alaska, November 21, 2004

NORTH ALASKA FORECAST DISCUSSION
600 AM AST SUN NOV 21 2004

.DISCUSSION...MORE SHORT TERM ACTION WITH GALES, ROUGH SEAS AND
COASTAL FLOODING ON THE BERING SEA COAST FROM DALL POINT TO BERING
STRAIT IS DUE TODAY AND TONIGHT. BUT TODAY, THE END OF THIS IS IN
SIGHT.

LOW #1 FOR TODAY IS UP IN THE CHUKCHI SEA AND WEAKENING. THIS
BROUGHT MINOR COASTAL FLOODING TO THE YUKON DELTA LAST NIGHT. THE
LOW IS WEAKENING AND IS NO LONGER MUCH OF A FACTOR.

LOW #2 IS ABOUT 100 MILES SOUTHWEST OF THE PRIBILOFS AND HEADED
NORTHWARD. THIS ONE PACKS SOME STORM FORCE WINDS, AND BY THE TIME IT
GETS TO THE NORTH BERING SEA THIS AFTERNOON, IT WILL CAUSE WHOLE
GALES OVER THE NORTH BERING SEA. TIDES OVER THE YUKON DELTA SHOULD
CREST AROUND MIDNIGHT TONIGHT.

LOW #2 IS DUE IN THE WESTERN ALEUTIANS IN THE EARLY MORNING HOURS OF
MONDAY. UNLIKE ITS PREDECESSORS, THIS ONE WILL TURN EAST, AND HEAD
FOR THE WEST GULF OF ALASKA AT MID WEEK. THE AMERICAN AND BRITISH
MEDIUM RANGE FORECASTS AGREE THAT THE HIGH ENERGY PATTERN OVER THE
ALASKAN WEST COAST THAT WEVE SEEN FOR THE PAST SEVERAL DAYS IS
EASING.

A PERSISTENT LONG WAVE TROUGH ALOFT OVER THE BERING SEA IS FORECAST
TO EASE INTO THE NORTH GULF OF ALASKA TUESDAY AND WEDNESDAY. THIS
WILL BRING A SPELL OF COOLER WEATHER TO THE ALASKA MAINLAND, ALONG
WITH SOME LIGHT SNOW FOR MUCH OF THE INTERIOR. BUT ON FRIDAY, THE
SOUTH FLOW ALOFT OVER THE STATE IS PREDICTED BY THE MEDIUM RANGE
FORECAST MODELS TO REDEVELOP, THOUGH NOT AT THE STRENGTH WEVE SEEN
LATELY. THIS SHOULD BRING TEMPERATURES OVER THE MAINLAND IN GENERAL,
AND THE INTERIOR IN PARTICULAR, BACK UP TO THEIR CURRENTLY MILD
LEVELS FOR THIS TIME OF YEAR.

REGARDING FORECAST MODELS, THE AVIATION MODEL WAS CLOSER ON ITS
FORECAST OF LOW #2 THAN THE ETA, SO IT HAS BEEN USED FOR MUCH OF
TODAYS FORECAST PACKAGE. THE SNOW FROM LOW #1 OVER NORTHWEST ALASKA
WILL FADE OUT BY TONIGHT, AS EXTENSIVE RAIN AND SNOW WITH LOW #2
SWEEP UP OVER THE WEST COAST BY MIDNIGHT TONIGHT. THE SNOWFALL THAT
MANAGES TO REACH THE WEST INTERIOR WILL BE LIGHTER GOING EASTWARD.
ON TUESDAY, SNOW FROM THE GULF OF ALASKA WILL LIKELY SPREAD OVER THE
SOUTHEAST HALF OF THE INTERIOR OF NORTHERN ALASKA. THE EAST ARCTIC
WILL CONTINUE TO SEE ALMOST NO SNOWFALL. SEA ICE IN AREA 11A SHOULD
BEGIN ADVANCING AGAIN ON TUESDAY.

.AFG WATCH/WARNING/ADVISORIES...
PUBLIC...COASTAL FLOOD WARNING FOR ZONES 211-212-214 (BERING SEA
COAST FROM BERING STRAIT TO THE YUKON DELTA.) WIND ADVISORY FOR ZONE
201 NEAR CAPE LISBURNE LAND ZONE 214.
MARINE...GALE WARNING AREA 9. SMALL CRAFT ADVISORY AREAS 10B AND
11A. BRISK WIND ADVISORY AREA 10A. HEAVY FREEZING SPRAY AREA 11A.

TF NOV 04