Gale Warning 48, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
1020 AM AKDT TUE APR 9 2013

.DISCUSSION...
AN UNSEASONABLY VERY COLD AND DEEP UPPER LOW CENTER CONTINUES
TO BE THE CONTROLLING FEATURE FOR WEATHER OVER THE NORTHERN
ALASKA. THE LOW CENTER IS CURRENTLY OVER THE UPPER KUSKOKWIM
VALLEY. CURRENT MODEL SOLUTIONS CALL FOR THE UPPER LOW TO MOVE
EASTWARD AND SPLIT INTO TWO CENTERS BY THURSDAY AFTERNOON...THE
NORTHERN CENTER JUST SOUTH OF THE NICHOLSON PENINSULA IN CANADA
AND THE SOUTHWESTERN CENTER NEAR PRINCE WILLIAM SOUND. BY
THURSDAY AFTERNOON THE NORTHERN CENTER WILL BE NEAR BANKS ISLAND
AND THE SOUTHERN CENTER WILL MOVE TO THE ALASKA PANHANDLE. CURRENT
GFS/ECMWF MODEL RUNS INDICATE ANOTHER UPPER LOW CENTER MOVING
SOUTHEASTWARD OUT OF THE ARCTIC...ARRIVING ON THE NORTHWEST ALASKA
COAST BY SATURDAY MORNING AND DIVING INTO THE EASTERN INTERIOR BY
SUNDAY AFTERNOON. THIS WILL PROLONG THE DURATION OF THE
UNSEASONABLY VERY COLD AIRMASS OVER THE FORECAST AREA.

A 975 MB LOW CENTERED OVER THE EXTREME SOUTHEAST INTERIOR NEAR
THE ALCAN BORDER IS PROGGED TO MOVE TO NEAR MAYO THIS EVENING
FILLING TO AROUND 978 MB...WHILE A SECONDARY 983 MB CENTER
DEVELOPS SOUTHWEST OF GREAT BEAR LAKE. THIS NEW LOW WILL BECOME
THE SURVIVING CENTER AND MOVE TO NEAR SOUTHERN BANKS ISLAND BY
WEDNESDAY AFTERNOON AS A 986 MB LOW. STRONG WEST WINDS WILL
DEVELOP OVER THE EASTERN ARCTIC COAST BY NOON WEDNESDAY AS
THE PRESSURE GRADIENT INCREASES ACROSS THE EASTERN ARCTIC
COAST. THE EASTERN ARCTIC COAST WILL EXPERIENCE A LONG PERIOD
OF BLIZZARD CONDITIONS BEGINNING AROUND NOON WEDNESDAY AND
CONTINUING THROUGH FRIDAY.

WINTER WEATHER ADVISORIES FOR SNOW WILL CONTINUE IN MOST EASTERN
INTERIOR ZONES. SNOW IS EXPECTED TO TAPER OFF IN ZONE 225 BY THIS
EVENING AND IN ZONE 226 BY AROUND MIDNIGHT. ADVISORIES IN THE
OTHER EASTERN INTERIOR ZONES THROUGH 6 AM WEDNESDAY. BRISK WINDS
WITH LOW WIND CHILL AND POOR VISIBILITY IN BLOWING SNOW IN ZONE
206 PASSES ARE EXPECTED TO CONTINUE THROUGH TONIGHT.

IN THE EXTENDED PERIOD...BELOW NORMAL TEMPERATURES ARE LIKELY TO
CONTINUE OVER MOST OF NORTHERN ALASKA INTO THE MIDDLE OF NEXT
WEEK. THE ECMWF AND GFS ENSEMBLE MEANS SHOW AN ESSENTIALLY SIMILAR
STORY WITH A RIDGE POSITION OVER THE BERING SEA AND A TROUGH AXIS
ALONG OR JUST EAST OF THE ALCAN BORDER...RESULTING IN A NORTH TO
NORTHWEST FLOW ALOFT OVER MOST OF THE NORTHERN ALASKA MAINLAND.

THE LATEST NCEP/CPC ENSEMBLE MEAN EXTENDED TEMPERATURE FORECAST
CALLS FOR TEMPERATURES AVERAGING BELOW NORMAL FOR ALMOST ALL OF
THE NORTHERN ALASKA FORECAST AREA THROUGH THE END OF THE MONTH.

&&

.FIRE WEATHER...
NONE.

&&

.HYDROLOGY...
NO RIPENING OF THE SNOWPACK OR SOFTENING OF RIVER ICE IS EXPECTED
THROUGH EARLY NEXT WEEK...MEAN TEMPERATURES IN THE FORECAST AREA
WILL REMAIN WELL BELOW FREEZING...DAYTIME MAXIMUM TEMPERATURES
REACHING FREEZING AT BEST...BUT WILL BE BELOW FREEZING IN MOST
AREAS ON MOST OR ALL DAYS DURING THE NEXT WEEK.

&&

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

WINTER WEATHER ADVISORY FOR AKZ206-AKZ218-AKZ219-AKZ220-AKZ221-
AKZ222-AKZ223-AKZ224-AKZ225-AKZ226.

GALE WARNING FOR PKZ245.

BRISK WIND ADVISORY FOR PKZ210-PKZ220-PKZ225-PKZ245.
&&

RF APR 13