Small Craft Advisory 153, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
132 PM AKDT THU OCT 25 2012

.DISCUSSION...
STRONG BLOCKING HIGH ALOFT CENTERED OVER THE BERING SEA
WILL REMAIN NEARLY STATIONARY THROUGH SUN...THEN WEAKEN
SLOWLY AND BE PUSHED OFF TO THE WEST AS AN UPPER LOW
MOVES DOWN OUT OF THE HIGH ARCTIC AND DEVELOPS INTO AN
EXPANSIVE COLD TROUGH CENTERED OVER THE CNTRL/ERN AK
MAINLAND BY TUE. HIGH PRESSURE WILL REMAIN IN PLACE OVER
THE NRN AK INTERIOR AND WEST COAST BUT WEAKEN A FEW MB
THROUGH SAT. EXTENSIVE CLOUD COVER WILL SPREAD SOUTHWARD
OVER MUCH OF NORTHERN AK AS THE UPPER TROUGH DEVELOPS.
WHILE THE AIR MASS TEMPERATURES WILL BECOME NOTICEABLY
COOLER...CLOUD COVER WILL KEEP TEMPERATURES FROM DROPPING
SHARPLY.

OVER THE HIGH ARCTIC...
A 1012 MB LOW NEAR 79N/180W WILL MOVE
SEWD TO NEAR 75N/140W BY NOON FRI FILLING TO 1020 MB.
A NEW 1007 MB LOW IS PROGGED TO DEVELOP ABOUT 600 MILES W OF
WRANGEL ISLAND THIS EVENING...THEN TRAVEL ON AN ARCING COURSE
ACROSS THE HIGH ARCTIC...THEN DIVE SEWD TOWARDS THE WRN CANADA
ARCHIPELAGO BY MON...DEEPENING A FEW MB DURING THE PERIOD. BRISK
WEST WINDS ARE EXPECTED TO DEVELOP ALONG MOST OF THE ARCTIC COAST
FROM BARROW EAST BY SUN EVENING...WITH GALE FORCE WEST WINDS
POSSIBLE ALONG THE ZONE 204 COAST SAT EVENING THROUGH SUN NIGHT.
A TROUGH SWINGING SWD ON THE BACK SIDE OF THE LOW WILL TIGHTEN THE
PRESSIURE GRADIENT OVER THE WESTERN ARCTIC COAST MON NIGHT THROUGH
TUE...PRODUCING BRISK NORTH TO NORTHWEST WINDS OVER THE WESTERN
ARCTIC...WITH GALES OVER THE WESTERN MARINE AREAS. THE

COASTAL HAZARD POTENTIAL...
ELEVATED SURF AND A SMALL RISE IN SEA LEVEL ALONG THE ARCTIC
COAST BEGINNING OVER THE EASTERN ARCTIC COAST SAT AFTERNOON
AND OVER THE REST OF THE COAST FROM THE BARROW AREA EASTWARD
SAT EVENING OR LATER SAT NIGHT. THE STRONGEST WINDS AND HIGHEST
SURF WILL BE OVER THE EASTERN ARCTIC COAST SAT EVENING THROUGH
SUN NIGHT WHERE WESTERLY GALES ARE EXPECTED. BEACH EROSION
AND POSSIBLY SOME COASTAL FLOODING COULD OCCUR ALONG THE EASTERN
ARCTIC COAST. SEAS IN MARINE AREA PKZ245 COULD BE AS HIGH AS 11
FT. IT IS TOO EARLY AT THIS TIME TO PUT UP A HIGH SURF ADVISORY...BUT
IF THE MODELS MAINTAIN THEIR CONTINUITY...AN ADVISORY MAY HAVE TO
BE ISSUED FRIDAY. THE 18Z GFS AND 12Z ECMWF RUNS ARE NOW IN...AND
THEY AGREE WELL AND HAVE GOOD CONTINUITY WITH THE PRECEDING RUNS.
FARTHER DOWN THE ROAD...SUN NIGHT THROUGH TUE...ELEVATED SURF AND
SEA LEVEL MAY OCCUR ALONG THE COAST FROM BARROW WESTWARD DUE TO AN
EXTENDED PERIOD OF N TO NW WINDS 25-40 KT OVER A LONG FETCH OF
OPEN WATER.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY FOR PKZ225-PKZ230-PKZ235.
&&

RF OCT 12