Brisk Wind Advisory 46, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
252 AM AKST WED FEB 4 2015

.DISCUSSION...

UPPER AIR...
A STRONG BLOCKING HIGH CENTERED ABOUT 100 MILES SOUTHWEST OF ST
LAWRENCE ISLAND WILL BE PUSHED TO JUST WEST OF THE GULF OF ANADYR
BY FRI AFTERNOON AS A SHORT WAVE TROUGH PUNCHES SOUTHWARD ACROSS
THE ARCTIC OCEAN AND THE ALASKA MAINLAND. THE SHORT WAVE TROUGH
AND NORTHERLY FLOW WILL BRING A COLDER AIR MASS TO NORTHERN ALASKA
BY FRIDAY. SOME RIDGING WILL BUILD ACROSS THE NORTHERN INTERIOR
AND THE BROOKS RANGE BUT THIS WILL HAVE NO EFFECT ON SURFACE
TEMPERATURES. CURRENT MODELS AND THE GEFS/ECMWF/NAEFS MEANS
INDICATE DEEP COLD PERSISTING OVER NORTHERN ALASKA THROUGH
MONDAY. A LITTLE MODERATION IS POSSIBLE OVER THE EXTREME SOUTHERN
INTERIOR TUESDAY AS A RIDGE BEGINS TO BUILD ALONG THE EASTERN
COAST. BY WEDNESDAY...MODERATION OF TEMPERATURES IS EXPECTED
OVER MOST AREAS SOUTH OF THE BROOKS RANGE AS THE SOUTHERLY
FLOW ALOFT EXPANDS FARTHER NORTHWARD...BRINGING IN WARMER
AIR FROM THE SOUTH. GEFS/ECMWF/NAEFS ENSEMBLE MEAN 850 MB
TEMPERATURE PROGS ARE IN GENERAL AGREEMENT IN INDICATION OF THIS
MODERATING TREND.

SURFACE...
1010-1035 MB HIGH PRESSURE IS EXPANDING EASTWARD ACROSS THE
ARCTIC SLOPE AND THE BROOKS RANGE. WINDS AT DEADHORSE...POINT
THOMPSON...AND BARTER ISLAND ARE SHOWING A VERY SLOW DECREASING
TREND...AND VISIBILITY AT BARTER ISLAND HAS IMPROVED TO 1 MILE
OR GREATER. SOME FURTHER IMPROVEMENT IN VISIBILITY OVER THE
EASTERN ARCTIC COAST IS EXPECTED TODAY...BUT IT WILL BE SLOW AS
WIND SPEEDS DECREASE VERY SLOWLY. A CONTINUE SLOW DECREASE IN
WINDS IS EXPECTED TONIGHT OVER THE EASTERN ARCTIC COAST. AS THE
HIGH PRESSURE DRIFTS EAST...EAST TO SOUTHEAST WINDS AS HIGH AS
15-20 MPH ARE EXPECTED TO REDEVELOP OVER THE WESTERN ARCTIC COAST
AND PORTIONS OF THE NORTHERN PLAIN IN ZONE 205...PRODUCING LOW
WIND CHILL WITH SURFACE TEMPERATURES AROUND -30F OR COLDER. WIND
CHILL WARNINGS FOR THESE AREAS WILL BE ISSUED WITH THIS MORNINGS
FORECAST PACKAGE.

THE HIGH PRESSURE CENTER WILL MOVE SOUTHEASTWARD INTO THE YUKON
TERRITORY AND NORTHWEST TERRITORIES BY THU AFTERNOON. GFS/NAM/ECMWF
MODELS ALL INDICATING A SURFACE TROUGH MOVING EASTWARD TO THE
CHUKCHI SEA BY THU MORNING. THE TROUGH WILL MOVE EASTWARD ACROSS
THE BEAUFORT SEA...REACHING LONGITUDE 140W BY FRI MORNING AS IT
BRUSHES THE EASTERN ARCTIC COAST. AS THIS TROUGH EXITS...A STRONG
BUT NARROW RIDGE OF HIGH PRESSURE WILL BUILD EASTWARD ACROSS THE
INTERIOR ARCTIC SLOPE LATE THU NIGHT INTO FRI. STRONG WEST WINDS
ARE EXPECTED TO REDEVELOP LATE THU NIGHT OR FRI MORNING OVER THE
CENTRAL AND EASTERN ARCTIC COAST AS A FAVORABLE PRESSURE GRADIENT
AND ISOBAR ORIENTATION SETS UP. WINDS WILL ALSO INCREASE OVER THE
REMAINDER OF THE ARCTIC COAST...BUT NOT BE AS STRONG AS WINDS
EXPECTED OVER THE CENTRAL AND EASTERN ARCTIC COAST. BLIZZARD
CONDITIONS WILL LIKELY REDEVELOP OVER THE EASTERN ARCTIC COAST BY
FRI MORNING... WITH REDUCED VISIBILITY IN BLOWING SNOW
REDEVELOPING OVER THE CENTRAL ARCTIC COAST BY LATE THU NIGHT OR
FRI MORNING. IN ADDITION TO THE REDUCED VISIBILITY...LOW WIND
CHILL COULD BE A POTENTIAL ISSUE AS COLDER AIR MOVES INTO THE
ARCTIC SLOPE.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...

WIND CHILL WARNING FOR AKZ201-AKZ205

BRISK WIND ADVISORY FOR PKZ245.

&&

RF FEB 15