Blizzard in Alaska, February 3, 2015

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
306 AM AKST TUE FEB 3 2015

.DISCUSSION...
CURRENT MODEL RUNS ARE IN GOOD AGREEMENT OUT THROUGH 84 HOURS AND
AGREE WELL WELL WITH THE PRECEDING RUNS.

UPPER AIR...
BLOCKING HIGH CENTERED OVER THE NORTHERN BERING SEA IS PROGGED TO
REMAIN NEARLY STATIONARY THROUGH FRI...THEN DRIFT SLOWLY WESTWARD
TO THE KAMCHATKA PENINSULA NECK BY MON. SEVERAL SHORT WAVE TROUGHS
WILL MOVE OVER THE TOP OF THE BLOCKING HIGH AND SOUTHEASTWARD
ACROSS NORTHERN ALASKA...IMPORTING COLDER AIR INTO NORTHERN
ALASKA. TEMPERATURES ARE EXPECTED TO BE WELL BELOW NORMAL BY
THE WEEKEND.

THE FIRST SHORT WAVE TROUGH WILL BE SWEEPING ACROSS NORTHWEST
ALASKA THIS MORNING AND ACROSS NORTHEAST ALASKA THIS AFTERNOON...
MOVING INTO THE YUKON TERRITORY THIS EVENING.

THE NEXT SHORT WAVE TROUGH WILL MOVE EASTWARD ACROSS THE CHUKCHI
SEA THU MORNING...AND EASTWARD ACROSS THE BEAUFORT SEA AND
NORTHEASTERN ALASKA THU AFTERNOON AND THU NIGHT.

THE THIRD SHORT WAVE TROUGH IN THE SERIES WILL BE MORE VIGOROUS...
MOVING ACROSS THE NORTHWEST ALASKA FRI MORNING AND DEEPEN INTO A
SUBSTANTIAL TROUGH OVER THE SOUTHERN AND SOUTHEASTERN MAINLAND BY
SAT MORNING. THIS SHORT WAVE WILL A DEEP COLD AIR MASS TO NORTHERN
ALASKA...WITH 850 MB TEMPERATURES NEAR -30 CELSIUS IN SOME AREAS.

THE DEEP COLD WILL LIKELY LAST THROUGH MON. CURRENT OPERATIONAL
RUNS OF THE GFS/ECMWF...ALONG WITH THEIR ENSEMBLE MEANS AND
THE NAEFS ENSEMBLE MEAN...ARE IN GOOD AGREEMENT SHOWING THIS
COOLING TREND...WITH SOME MODERATION SOUTH OF THE BROOKS RANGE
BEGINNING TUESDAY AS A RIDGE DEVELOPS OVER THE SOUTHEAST ALASKA
INTERIOR AND NORTHWEST CANADA...BRINGING SOUTH TO SOUTHWEST FLOW
ALOFT TO MOST AREAS SOUTH OF THE BROOKS RANGE.

SURFACE...
A 1008 MB LOW CENTERED ABOUT 100 MILES NORTH OF THE MACKENZIE
RIVER DELTA AT 9PM MON WILL MOVE EASTWARD...OPENING UP INTO A
A BROAD TROUGH EXTENDING FROM BANKS ISLAND NORTHWARD BY THIS
AFTERNOON. THE SEA LEVEL PRESSURE GRADIENT IS EXPECTED TO
TIGHTEN OVER THE CENTRAL AND EASTERN ARCTIC COAST TODAY AS THE
LOW MOVES EAST AND HIGH PRESSURE WEST OF WRANGEL ISLAND BUILDS
EASTWARD. THIS WILL RESULT IN SOME INCREASE OF THE WINDS OVER THE
CENTRAL AND EASTERN ARCTIC COAST TODAY. WINDS OVER THESE AREAS
WILL DIMINISH BY WED AS HIGH PRESSURE EXPANDS EASTWARD ACROSS THE
ARCTIC SLOPE. THE STRONGEST WINDS WILL BE OVER THE EASTERN ARCTIC
COAST. BARTER ISLAND CURRENTLY REPORTING WEST WINDS 35-40 MPH
WITH GUSTS EXCEEDING 45 MPH...ALONG WITH VISIBILITY 1/4 TO 1/2
MILE IN SNOW AND BLOWING SNOW.

ANOTHER LOW PRESSURE TROUGH WITH AN ASSOCIATED COLD FRONT WILL
MOVE EASTWARD TO THE CHUKCHI SEA BY WED MORNING...SWEEPING
ACROSS THE BEAUFORT SEA...ARCTIC SLOPE...AND BRUSHING THE
BROOKS RANGE THU AFTERNOON AND THU NIGHT. THIS WILL CAUSE
ANOTHER PERIOD OF SNOW AND STRONG WEST WINDS ACROSS THE CENTRAL
AND EASTERN ARCTIC COAST BEGINNING LATE THU NIGHT. THESE STRONG
WINDS COULD LAST INTO SAT...WITH THE STRONGEST WINDS AND LIKELY
ANOTHER BLIZZARD OVER THE EASTERN ARCTIC COAST. THERE IS A GOOD
LIKELIHOOD THAT THIS SECOND BLIZZARD WILL BE MORE SEVERE THAN
THE CURRENT ONGOING EVENT. BRISK NORTH WINDS MAY DEVELOP OVER THE
BERING SEA AS VERY STRONG HIGH PRESSURE BUILDS EASTWARD OVER THE
NORTHERN AND NORTHEASTERN SIBERIA COAST AND ADJOINING AREAS IN THE
ARCTIC OCEAN.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
BLIZZARD WARNING FOR AKZ204.

WINTER WEATHER ADVISORY FOR AKZ203-AKZ206.

GALE WARNING FOR PKZ245.

BRISK WIND ADVISORY FOR PKZ225-PKZ240-PKZ245.
&&

RF FEB 15