Small Craft Advisory 157, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
332 AM AKDT SAT OCT 27 2012

.DISCUSSION...

MODELS...GOOD AGREEMENT ALOFT AND AT THE SURFACE THROUGH 72 HOURS.
SOME MINOR DIFFERENCES IN POSITION OF THE LOW IN THE ARCTIC AS WE
GET PAST 42 HOURS WILL EFFECT SURFACE WIND DIRECTION ALONG THE
ARCTIC COAST.

ALOFT...AT 500 HPA...REX BLOCK WILL SLOWLY BREAK DOWN NEXT 48
HOURS. A 575 DAM CLOSED HIGH OVER BERING STRAIT THAT WILL MOVE TO
200 NM SOUTH OF ST LAWRENCE ISLAND BY SATURDAY NIGHT AND CONTINUE
TO THE CENTRAL BERING SEA BY SUNDAY NIGHT AND EVENTUALLY OVER THE
KAMCHATKA PENINSULA BY WEDNESDAY MORNING AS A 568 DAM CLOSED HIGH.
A SHORT WAVE WILL DEVELOP IN THE ARCTIC NORTHWEST OF WRANGEL
ISLAND SATURDAY AND MOVE TO WRANGEL ISLAND BY SUNDAY AFTERNOON. A
519 DAM LOW WILL DEVELOP ALONG THE WAVE NEAR 80N 180 AND MOVE OVER
DEADHORSE AS A 515 DAM CLOSED LOW BY MONDAY MORNING THEN CONTINUE
MOVING SOUTH OVER THE EASTERN INTERIOR AND EVENTUALLY OVER PRINCE
WILLIAM SOUND BY WEDNESDAY MORNING AS A 517 DAM LOW. AT 840
HPA...TEMPERATURES ABOVE ZERO CONTINUE TO ENCROACH ON THE WESTERN
HALF OF THE STATE AND THE NORTHWEST COAST OF THE ARCTIC. THE WARM
AIR WILL BE PUSHED SOUTH AS NORTHERLY FLOW DEVELOPS OVER THE WEST
COAST SUNDAY NIGHT WITH ALL OF THE CWA RETURNING TO BELOW ZERO
TEMPERATURES BY MONDAY MORNING.

SURFACE...BROAD AREA OF HIGH PRESSURE CONTINUES ACROSS THE
INTERIOR AND WEST OVER THE BERING SEA. A 1018 MB LOW IS 300 NM
NORTH OF BARTER ISLAND AND WILL MOVE TO MACKENZIE BAY CANADA TODAY
AND DISSIPATE. A 1012 MB LOW NEAR 73N 155E WILL MOVE TO 76N 175W
AT 1011 MB THIS MORNING THEN TO 300 NM NORTH OF DEADHORSE BY
SUNDAY MORNING AT 1009 MB. A SECOND LOW WILL DEVELOP JUST NORTH
OF DEMARCATION POINT SATURDAY NIGHT AND MOVE TO MACKENZIE BAY
SUNDAY NIGHT THEN COMBINE WITH THE FIRST LOW AS A 1007 MB LOW. A
1014 MB LOW WILL DEVELOP OVER THE CENTRAL BROOKS RANGE THEN MOVE
SOUTHEAST OVER THE YUKON FLATS THEN TO NEAR EAGLE BY MONDAY NIGHT.
STRONG GRADIENT DEVELOPS SOUTH OF THE LOW IN THE ARCTIC ON
SATURDAY NIGHT AND THEN WEST OF THE LOW SUNDAY NIGHT THROUGH
WEDNESDAY.

ARCTIC COAST...AS THE LOW NEAR 73N 155E MOVES EAST A FRONTAL
BOUNDARY WILL PUSH ACROSS THE ARCTIC COAST WITH SNOW SHOWERS OR
FLURRIES. NO FREEZING RAIN EXPECTED TODAY AS WARM AIR THAT HAS
BEEN OVER THE WESTERN ARCTIC COAST IS FORCED SOUTH. WEST WINDS
TODAY WILL TURN NORTHWEST TONIGHT AND THEN NORTH SUNDAY NIGHT.
STRONGEST WINDS ALONG THE EASTERN ARCTIC COAST...BUT PERSISTENT
WINDS AROUND 25 KNOTS ALONG MOST OF THE COAST THROUGH WEDNESDAY.
HIGH SURF EXPECTED TONIGHT WEST OF PT BARROW IN ZONE 202 AND IN
ZONE 204. WINDS PARALLEL THE COAST IN ZONE 203 SO DO NOT EXPECT
ISSUES UNTIL THE WINDS TURN NORTH THERE ON TUESDAY. HIGH SURF
CONDITIONS EXPECTED TO DIMINISH MONDAY IN ZONE 204 BUT PERSIST
INTO WEDNESDAY IN ZONE 202. HIGH SURF ISSUES DEVELOP IN ZONE 201
SUNDAY NIGHT AND CONTINUE THROUGH WEDNESDAY.

WEST COAST...PRETTY QUIET. SOME STRATUS FLOATING AROUND WILL BE
THE MAIN ISSUE TODAY...BUT NORTH FLOW DEVELOPING SUNDAY SHOULD
PUSH MOST OF THAT OUT AS COLDER DRIER AIR MOVE SOUTH. EXPECT SOME
FLURRIES OR EVEN LIGHT SNOW WITH THE NORTH FLOW...MAINLY OVER THE
COASTAL AREAS. INTERIOR ZONES SHOULD REMAIN MOSTLY CLEAR THROUGH
MID WEEK.

INTERIOR...LARGE PATCH OF STRATUS OVER THE INTERIOR COVERS ZONES
220...221...222...223...AND 224. STRATUS WILL SLOWLY DISSIPATE
THROUGH THE DAY. EXPECT A FEW FLURRIES OUT OF IT WHILE IT HANGS
AROUND. EXPECT ANOTHER CHANCE OF SNOW TONIGHT IN THE EASTERN
INTERIOR AS LOW DEVELOPS OVER THE CENTRAL BROOKS RANGE THEN MOVES
TO NEAR EAGLE. NOT MUCH CHANGE IN TEMPERATURES THE NEXT SEVERAL
DAYS. COOLER AIR FLOWS INTO THE INTERIOR...BUT MORE CLOUDS
WILL MODERATE THOSE TEMPERATURES UNLESS WE CLEAR OUT.

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...MODERATE AND PERSISTENT
NORTH WINDS OVER THE ARCTIC COAST WILL CONTINUE THE POTENTIAL FOR
MINOR EROSION PROBLEMS.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY FOR AKZ202-AKZ204.

SMALL CRAFT ADVISORY FOR PKZ230-PKZ235-PKZ240-PKZ245.

GALE WARNING FOR PKZ245.

HEAVY FREEZING SPRAY WARNING FOR PKZ500-PKZ505.

&&

SDB OCT 12