High Surf Advisory 8, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
410 PM AKDT SUN OCT 30 2011

.SYNOPSIS...
ALOFT...
THE LONG WAVE TROUGH OVER WESTERN ALASKA WILL PROGRESS EAST OVER
MAINLAND ALASKA MON AND TUE BEFORE MOVING INTO NW CANADA WED.
THIS WILL BRING COLDER TEMPERATURES INTO NORTHERN ALASKA THROUGH
MID-WEEK.

A VERY DEEP LOW IN THE HIGH ARCTIC IS PRODUCING A STRONG WESTERLY
ARCTIC JET ACROSS THE CHUKCHI AND BEAUFORT SEAS THROUGH TUE. THIS
WILL BRING STRONG DYNAMICS WITH STRONG WESTERLY FLOW AND COLD
ADVECTION TO THE ARCTIC COAST THE NEXT SEVERAL DAYS. THIS
ADVECTION OF 850 MB AIR COLDER THAN -20C ALONG WITH 500 MB HEIGHTS
LESS THAN 5000M AND DEEP NORTHWEST FLOW PARALLEL TO THE ICE EDGE
IS SETTING UP FOR POTENTIAL SIGNIFICANT POLAR LOW DEVELOPMENT IN
THE CHUKCHI SEA MON NIGHT. THIS COULD HAVE A SIGNIFICANT IMPACT ON THE
ARCTIC COAST IN TERMS OF POSSIBLE COASTAL FLOODING AND POSSIBLE
BLIZZARD CONDITIONS STARTING EARLY TUE AND CONTINUING INTO WED.

A SHORT WAVE TROUGH FROM BETTLES TO DENALI WILL MOVE EAST TO THE
ALCAN BORDER BY MON AM. SNOW SHOWERS EAST OF THE TROUGH WILL
DIMINISH TO FLURRIES WEST OF THE TROUGH WITH SOME CLEARING WEST OF
THE TROUGH.

SURFACE...
A 980 MB LOW 600 NM NORTH OF BARROW WILL REMAIN STATIONARY
THROUGH TUESDAY AND WEAKEN SLOWLY. A COLD FRONT STRETCHING
SOUTHWEST FROM THE LOW WILL MOVE ALONG THE ARCTIC COAST OF ALASKA
MON. THIS IS NOW CAUSING SNOW SHOWERS AND SW WINDS 25 KT ALONG THE
WESTERN ARCTIC COAST. WINDS AND SNOW WILL DIMINISH AS THIS FRONT
MOVES EAST OF BARROW. EXPECT AN INCH OR SO OF SNOW. DID NOT ISSUE
A WINTER WEATHER ADVISORY WITH THIS TO AVOID CONFUSION WITH WATCH
FOR TUE.

A STRONG 995 MB POLAR LOW WILL DEVELOP IN THE NORTHERN CHUKCHI SEA
MON NIGHT AND MOVE TO 100 NM NORTH OF PRUDHOE BAY AS A 990 MB LOW
BY 4PM TUE. THIS COULD CAUSE BLIZZARD CONDITIONS TUE-WED ALONG THE
ARCTIC COAST WITH 4-6 INCHES OF SNOW AND WEST WINDS GUSTING 40-50
MPH. SINCE MODELS DUE VERY POORLY WITH POLAR LOWS THIS COULD
EASILY BE STRONGER THAN MODELS FORECAST. EXPECT THIS TO BE THE
STRONGEST STORM SO FAR THIS SEASON ALONG THE ARCTIC COAST.
THERE IS A LONG ENOUGH FETCH LENGTH COMBINED WITH THE VERY STRONG
WINDS AND VERY STRONG COLD ADVECTION TO RAISE SEA LEVELS 1-2 FT
AND CAUSE SOME COASTAL FLOODING AND RAFT ICE ONSHORE FROM BARROW
WEST TUE- WED. MORE SHORE FAST ICE EAST OF BARROW MAY PREVENT ANY
FLOODING FROM OCCURRING THERE.

THIS STORM COULD PUSH HIGHER WATER INTO KOTZEBUE SOUND LATE TUE-WED
BUT AT THIS POINT SURGE MODELS DO NOT SHOW A SIGNIFICANT RISE. WILL
NEED TO KEEP AND EYE ON THIS AREA AS WELL.

A STRONG LOW IN THE CENTRAL BERING SEA WILL MOVE EAST INTO THE
GULF OF ALASKA MON NIGHT. THIS IS CAUSING NE WINDS 15-25 KT ALONG
THE WEST COAST FROM THE BERING STRAIT SOUTH THAT WILL DECREASE
LATE MON.

&&

.DISCUSSION...
MODELS INITIALIZE WELL AND SHOW SIMILAR SOLUTIONS 4PM MON. AFTER
THAT NAM IS FASTER WITH MOVEMENT OF GULF OF ALASKA LOW. PREFER
SLOWER GFS SOLUTION DUE TO THE STRONG COLD ADVECTION OVER THE
GULF OF ALASKA CAUSING THE LOW TO REMAIN AT LEAST PARTLY ANCHORED
THERE. EXPECT SEVERAL INCHES OF SNOW IN THE SE INTERIOR TUE FROM
THAT FEATURE.

THE GFS IS ALSO DEEPER WITH THE POTENTIAL POLAR LOW DEVELOPING IN
THE NORTHERN CHUKCHI SEA MON NIGHT AND IS PREFERRED ON THAT
FEATURE AS WELL. EXPECT THAT FEATURE TO BE STRONGER THAN ANY
MODELS AND HAVE BUMPED WINDS UP 3-5 KT FROM ANY MODELS NEAR THIS POLAR
LOW.

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

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
BLIZZARD WATCH FOR AKZ201-AKZ202-AKZ203-AKZ204.

COASTAL FLOOD WATCH FOR AKZ201-AKZ202.

HEAVY FREEZING SPRAY WARNING FOR PKZ230.

SMALL CRAFT ADVISORY FOR PKZ210-PKZ220-PKZ225-PKZ230.

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

JB OCT 11

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE FAIRBANKS AK
912 PM AKDT SUN OCT 30 2011

AKZ201>204-311400-
WESTERN ARCTIC COAST-NORTHERN ARCTIC COAST-
CENTRAL BEAUFORT SEA COAST-EASTERN BEAUFORT SEA COAST-
INCLUDING...WAINWRIGHT...ATQASUK...POINT LAY...CAPE LISBURNE...
BARROW...ALAKTAK...PITT POINT...NULAVIK...NUIQSUT...PRUDHOE BAY...
ALPINE...DEADHORSE...KUPARUK...KAKTOVIK...FLAXMAN ISLAND
912 PM AKDT SUN OCT 30 2011

...STORMY WEATHER IS EXPECTED ON THE ARCTIC COAST OVER THE NEXT
TWO DAYS...

A WEATHER FRONT MOVED ACROSS THE WESTERN ARCTIC COAST SUNDAY
AFTERNOON AND EVENING. WEST WINDS TO 30 MPH AND BLOWING SNOW WERE
OBSERVED FROM WAINWRIGHT TO BARROW. THE WINDS AND BLOWING SNOW
HAVE NOW DIMINISHED.

A SECOND AND CONSIDERABLY STRONGER STORM IS EXPECTED TO DEVELOP IN
THE CHUKCHI SEA MONDAY NIGHT. THIS STORM WILL APPROACH THE ALASKAN
ARCTIC COAST MONDAY NIGHT. NORTHWEST WINDS AS STRONG AS 45 MPH
WILL DEVELOP ON THE WESTERN ARCTIC COAST TUESDAY MORNING AND
SPREAD TO THE EASTERN ARCTIC COAST TUESDAY AFTERNOON.

BLIZZARD CONDITIONS ARE POSSIBLE ON THE WESTERN ARCTIC COAST
TUESDAY AND TUESDAY NIGHT...AND ON THE ARCTIC COAST EAST OF BARROW
FROM TUESDAY AFTERNOON THROUGH WEDNESDAY AFTERNOON.

IN ADDITION...THE CHUKCHI SEA WEST OF BARROW IS STILL ALMOST
COMPLETELY ICE FREE. THIS...AND GALE FORCE WEST WINDS STARTING ON
MONDAY EVENING...HAS THE POTENTIAL TO BRING COASTAL FLOODING FROM
CAPE LISBURNE UP TO POINT BARROW FROM LATE MONDAY NIGHT THROUGH
LATE TUESDAY NIGHT.

THE TIMING OF THESE DEVELOPMENTS REMAINS A LITTLE UNCERTAIN.
HOWEVER...THIS INBOUND STORM COULD TURN OUT TO BE ONE OF THE MOST
IMPORTANT OF THE WINTER. THIS IS BECAUSE OF THE LARGE EXPANSE OF
ICE FREE WATERS WEST OF BARROW AND THE HEAVY SEAS EXPECTED IN THE
CHUKCHI SEA THROUGH MID WEEK.

BY THE END OF THE WEEK...THE WINTER PACK ICE WILL BE RAPIDLY
FORMING OVER THE CHUKCHI SEA NORTH OF POINT LAY. THIS WILL
GREATLY LESSEN THE CHANCES FOR COASTAL FLOODING NORTH OF POINT
HOPE. EAST OF BARROW...THE SEA ICE COVER IS NEARLY COMPLETE.