Blizzard in Alaska, December 9, 2013

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
245 AM AKST MON DEC 9 2013

.DISCUSSION...

MODELS...RUN TO RUN CONTINUITY REMAINS VERY GOOD...AND THE MODELS
CONTINUE TO SHOW GOOD CONSENSUS ON SOLUTIONS THROUGH ABOUT 72
HOURS. LEANING ON A BLEND OF THE MODELS FOR THE SHORT TERM SINCE
THIS HAS WORKED FAIRLY WELL THE LAST COUPLE DAYS. WILL NUDGE TO
THE GFS FOR MAXIMUM TEMPERATURES AGAIN TODAY AND THE BIAS
CORRECTED NAM FOR MINIMUM TEMPERATURES. ALL THE MODELS CONTINUE TO
DEVELOP STRONG WINDS FROM BARTER ISLAND TO THE LOWER YUKON DELTA
BY WEDNESDAY MORNING SO WILL USE A BLEND.

ALOFT...AT 500 HPA...574 DAM RIDGE OVER THE GULF OF ALASKA IS
RECEDING SOUTH WHILE A BRANCH OF IT POKES NORTHWEST OVER THE
BERING STRAIT. THE BRANCH OVER THE BERING STRAIT WILL PINCH OFF
AND DRIFT NORTH AS FAIRLY STRONG SHORTWAVE PUSHES SOUTH OVER THE
CENTRAL BROOKS RANGE BY TONIGHT AND THEN CONTINUES TO OVER THE
CENTRAL INTERIOR BY TUESDAY MORNING. LONG WAVE TROUGH WILL LIE EAT
TO WEST ALONG THE ALASKA RANGE BY LATE TUESDAY REMAINING
STATIONARY. A 514 DAM CLOSED LOW WILL DEVELOP OVER THE WESTERN
ALASKA RANGE EARLY THURSDAY AND STRENGTHEN AS HEIGHTS FALL TO 509
DAM BY THURSDAY NIGHT OVER SOUTHCENTRAL ALASKA. AT 850 HPA...ZERO
CELSIUS LINE EXTENDS FROM GAMBELL TO NORTHWAY THIS MORNING AND IS
MOVING SOUTH. TEMPERATURES RANGE FROM AROUND 2 CELSIUS ABOVE OVER
THE LOWER YUKON DELTA TO 14 CELSIUS BELOW OVER BARTER ISLAND. BY
TUESDAY MORNING THEY WILL FALL TO 4 TO 19 CELSIUS BELOW.

SURFACE...RIDGE REMAINS IN PLACE OVER MAINLAND ALASKA BUT IS
WEAKENING AND RETREATING TO THE SOUTH. A WEAK FRONTAL SYSTEM
EXTENDS FROM JUST SOUTH OF EAGLE TO CAPE ROMANZOF THIS MORNING AND
IS SLOWLY DRIFTING SOUTH AND BEING PULLED TO THE EAST. MODELS
DIFFER ON THE HANDLING OF THIS FEATURE WITH THE ECMWF KEEPING IT
HANGING AROUND WITH SOME PRECIPITATION...WHILE THE GFS HAS IT
DISSIPATING LATE THIS MORNING. THE ECMWF HAS HANDLED IT A LITTLE
BETTER UP TO THIS POINT SO WILL KEEP AT LEAST SOME FLURRIES FROM
FAIRBANKS EAST TODAY. SURFACE FEATURE ASSOCIATED WITH THE STRONG
SHORTWAVE MOVING OVER THE CENTRAL BROOKS RANGE WILL ENHANCE
PRECIPITATION AS IT MOVES INTO THE INTERIOR LATE TONIGHT. WINDS
OVER THE WESTERN AND NORTHERN INTERIOR WILL PICK UP AS THE LOW AT
850 HPA MOVES OVER THE UPPER YUKON FLATS LATE TONIGHT AND
NORTHEAST FLOW DEVELOPS ACROSS THE AREA.

ARCTIC COAST...1018MB LOW OVER THE NORTHWEST COAST THIS MORNING
WILL CONTINUE SOUTHEAST TO THE CENTRAL BROOKS RANGE THIS AFTERNOON
AND TO THE UPPER YUKON FLATS BY TUESDAY MORNING. RIDGING WILL
BUILD IN BEHIND THE LOW. SNOW OVER ALL BUT THE COASTAL AREAS EAST
OF BARROW TODAY AT SOME POINT. BY ARCTIC STANDARDS THE WINDS WILL
NOT BE TOO STRONG...BUT EXPECT SOME GUSTY WINDS TO 30 MP AS THE
LOW MOVES THROUGH THE AREA...THIS COULD CAUSE SOME ISSUES IN
ATIGUN PASS LATER TODAY. SOME CLEARING BEHIND THE FRONT TONIGHT
BUT ALSO EXPECT STRATUS WILL BE MOVING BACK IN BY TUESDAY
AFTERNOON.

WEST COAST AND WESTERN INTERIOR...PRETTY QUIET...SOME FLURRIES
TODAY BUT NO ORGANIZED AREAS OF PRECIPITATION. WINDS GENERALLY
LIGHT TODAY BUT LOOK FOR THEM TO START RAMPING UP LATE THIS
EVENING. BOUNDARY LAYER WINDS UP TO 40 KT DEVELOP OVER THE YUKON
VALLEY SO EXPECT WINDS AT THE SURFACE TO BE GUSTING TO 25 MPH WITH
GUSTS TO 40 MPH OVER THE SUMMITS. COLD AIR ADVECTION WILL
CONTINUE THROUGH THE WEEK.

INTERIOR...WEAK FRONTAL BAND OVER THE FAIRBANKS AREAS AND EAST IS
DRIFTING SLOWLY TO THE SOUTH. HAVE ISSUED WWA FOR HEAVY SNOW AS
AREAS IN THE BAND HAVE RECEIVED OVER 4 INCHES OF SNOW. MODELS DID
NOT INDICATE ANYTHING THAT HEAVY YESTERDAY BUT MODELS DO INDICATE
THAT THE FRONT WILL NOT BE MOVING TOO MUCH TODAY SO ADDITIONAL
SNOWFALL WILL CONTINUE THROUGH THE MORNING AROUND FAIRBANKS. THE
BAND IS BEING PULLED EAST SO THE FORTYMILE COUNTRY IS ALSO GETTING
A BLANKET OF NEW SNOW. NOT EXPECTING THE FRONT TO GET IN TO THE
UPPER TANANA VALLEY AND MAY NOT EVEN GET MUCH IN THE DELTA
JUNCTION AREA. SNOW DEVELOPING FROM NORTH TO SOUTH LATER TODAY AS
THE LOW PUSHES SOUTH SO ANOTHER BOUT WITH UP TO 2 INCHES OF SNOW
EXPECTED TONIGHT. DO EXPECT SOME WINDS IN THE HILLS BEHIND THE LOW
BUT PRIMARILY TO THE NORTH AND WEST OF FAIRBANKS. GUSTS TO AROUND
40 MPH ON SUMMITS AND TO 25 MPH AT THE SURFACE.

&&

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FOR AKZ221-AKZ222-AKZ224.

SMALL CRAFT ADVISORY FOR PKZ210-PKZ220-PKZ225.

BRISK WIND ADVISORY FOR PKZ230-PKZ235-PKZ240-PKZ245.
&&

SDB DEC 13