Blizzard in Alaska, January 19, 2015

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
147 AM AKST MON JAN 19 2015

.DISCUSSION...
MODELS INITIALIZED WELL AGAINST THE 06Z ANALYSIS AND CONTINUE TO
PERFORM WELL IN THE SHORT TERM. WILL LEAN ON INHERITED FORECAST
COMBINED WITH A BLEND OF GFS AND NAM FOR SHORT TERM FORECAST.

ALOFT AT 500 HPA... A 495 DAM LOW CENTERED OVER THE CHUKOTSK
PENINSULA WILL CONTINUE TO DRIFT NORTH AND EAST TO BE LOCATED 100
NM NORTHWEST OF POINT HOPE THIS EVENING AND WILL DRIFT NORTH TO BE
LOCATED 250 NM WEST OF BARROW BY TUESDAY MORNING. A SHORT WAVE
TROUGH EXTENDING SOUTH FROM THE UPPER LEVEL LOW WILL PUSH EASTWARD
INTO THE WEST COAST BY MONDAY EVENING AND PUSH INTO THE WESTERN
INTERIOR TUESDAY MORNING AS A WAVE MOVES NORTHEAST ALONG THE BACK
SIDE OF AN UPPER LEVEL RIDGE THAT REMAINS PARKED OVER THE YUKON
AND EXTENDING SOUTHEAST ALONG THE COAST TO CALIFORNIA. A JET MAX
ROTATING AROUND THE SOUTHERN SIDE OF THE UPPER LEVEL LOW WILL
CREATE A FAVORABLE AXIS OF ENHANCED LIFT ALONG THE A LINE FROM ST
MATTHEW ISLAND NORTHEAST TO THE BERING STRAIT. ST LAWRENCE ISLAND
IS UNDER THE CROSS HAIRS AND WILL EXPERIENCE A PROLONGED PERIOD OF
UPPER LEVEL LIFT AND COMBINED WITH A PLUME OF MOIST AIR WILL
PRODUCE 6 TO 12 INCHES OF SNOW OVER ST LAWRENCE ISLAND NORTHEAST
INTO THE BERING STRAIT.

ON THE SURFACE...AN ELONGATED LOW PRESSURE CURRENTLY LOCATED 100
NM NORTH OF SHEMYA AS A 989 MB WILL REMAIN NEARLY STATIONARY AS
AN INVERTED TROUGH EXTENDING NORTHEAST FROM THE LOW TROUGH THE
BERING STRAIT AND TO JUST WEST OF POINT HOPE PULLS AMPLE MOISTURE
NORTHEASTWARD. A BAND OF ENHANCED SNOW WILL TRAIN NORTHEAST ALONG
THIS BOUNDARY INTO MONDAY NIGHT. WINTER STORM WARNINGS FOR SNOW
AND BLOWING SNOW HOISTED FOR ZONE 213 AND WINTER WEATHER ADVISORY
FOR BLOWING SNOW IN EFFECT FOR ZONE 207 AS WINDS AND SNOW
INCREASE.

ON THE NORTH SLOPE...A DECAYING BOUNDARY JUST WEST OF BARROW CONTINUES
TO MOVE NORTH AND EAST AND WILL BRING SCATTERED SNOW SHOWERS OVER
THE EASTERN NORTH SLOPE. SNOW WILL DEVELOP THIS MORNING ALONG THE
WESTERN NORTH SLOPE AS THE LOW OVER THE BERING STRAIT CONTINUES TO
MOVE TO THE NORTH.

WEST COAST AND WESTERN INTERIOR...SCATTERED SNOW SHOWERS WILL
GIVE WAY TO SCATTERED FLURRIES AND MOSTLY CLOUDY SKIES AS THE
FRONT CONTINUES TO MOVE INTO THE CENTRAL INTERIOR.

CENTRAL AND EASTERN INTERIOR...EXPECT SCATTERED SNOW SHOWERS AHEAD
OF THE FRONT NORTH OF FAIRBANKS WIT A TRANSITION TO SCATTERED
FLURRIES. EXPECT SCATTERED FLURRIES ACROSS THE SOUTHERN INTERIOR.
MOSTLY CLOUDY SKIES AND AREAS OF FOG EXPECTED OVER THE ENTIRE
INTERIOR.

CONSIDERABLE DIFFERENCES IN THE MODELS EXIST IN THE MID TERM AND
LONG TERM WITH RESPECT TO COLD AIR MOVING INTO THE INTERIOR. ECMWF
PLACES 850 MB TEMPERATURES OVER FAIRBANKS AT MINUS 12 WHILE GFS
DEPICTS A WEAK CHINOOK EVENT WITH 850 MB TEMPERATES AT PLUS 2
FRIDAY MORNING. IN SHORT...VERY LITTLE CONFIDENCE IN MID RANGE
FORECAST AT THIS POINT.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING FOR AKZ213.

WINTER WEATHER ADVISORY FOR AKZ207.

GALE WARNING FOR PKZ210.

BRISK WIND ADVISORY FOR PKZ210-PKZ215-PKZ220-PKZ225.
&&

CCC JAN 15