Small Craft Advisory 149, NWS Fairbanks, AK

NORTH ALASKA FORECAST DISCUSSION
600 AM ADT TUE OCT 11 2005

.DISCUSSION...
ALOFT...CLOSED LOW AT 500 MB IS CENTERED OVER NORTON SOUND AND
WILL REMAIN OVER THE SAME GENERAL AREA THROUGH THURSDAY. VORTICITY
MAXIMA WILL ROTATE AROUND THE LOW SUSTAINING LIFTING DYNAMICS
THROUGH THURSDAY FOR THE WEST COAST AND PORTIONS OF THE WESTERN
INTERIOR. TUESDAY...THE INTERIOR WILL EXPERIENCE A BRIEF RESPITE
WITH RIDGING. WEDNESDAY MORE CYCLONIC FLOW WILL RETURN WITH
SHORTWAVES IN SOUTHWESTERLY FLOW UNDERNEATH WEST COAST LOW. ON
THURSDAY...A SHORTWAVE WILL MOVE INTO THE NORTH SLOPE FROM THE
SOUTHEAST POSSIBLY BRINGING SOME PACIFIC MOISTURE INTO THE DRY
ARCTIC.

SURFACE...AN OLD OCCLUSION BOUNDARY OFF THE WEST COAST NOW
DEEPENING INTO A WEAK SURFACE LOW OF 990 MB IN NORTON SOUND. THE
LOW WILL MOVE NORTHWEST INTO BERING STRAIT ON WEDNESDAY AND INTO
THE CHUKCHI SEA ON THURSDAY. A STRONGER LOW OF 980 MB WILL MOVE
ASHORE AROUND YAKUTAT ON WEDNESDAY...POSSIBLY BRINGING AN
OCCLUSION WEDNESDAY EVENING INTO THE SOUTHEASTERN INTERIOR.
THURSDAY...ANOTHER LOW OF 995 MB WILL MOVE INTO THE CENTRAL BERING
SEA WITH MOISTURE RICH WARM FRONT STRETCHING EAST INTO BRISTOL
BAY. HIGH PRESSURE WILL REMAIN NORTH OF BARROW THROUGH WEDNESDAY
AND THEN RETREAT TO THE CANADIAN ARCTIC BY THURSDAY.

THE INTERIOR...SKIES WILL PART TODAY AS WARM AIR ALOFT PUSHES
NORTHWARD OVER THE REGION. HOWEVER...FRESH SNOW COVER WILL HOLD
TEMPERATURES AT THE SURFACE IN THE 30S AROUND FAIRBANKS. THE
EASTERN INTERIOR MAY DEAL WITH SOME SNOW WEDNESDAY ASSOCIATED WITH
THE LOW MOVING INTO YAKUTAT...WHILE THE CENTRAL INTERIOR WILL SEE
SNOW CHANCES INCREASE FROM THE WEST ON WEDNESDAY NIGHT AND
THURSDAY AS VORTICITY MAXIMA ROTATE AROUND THE WEST COAST LOW.

THE ARCTIC COAST AND NORTH SLOPE...PATCHY FREEZING DRIZZLE WITH
OCCASIONAL FLURRIES WILL OCCUR TODAY AND TONIGHT ACROSS THE ARCTIC
SLOPE. CLIMATOLOGICALLY...THIS IS THE TIME OF YEAR WITH THE MOST
OPEN WATER...SO LOOK FOR THESE EPISODES TO CONTINUE. AS AN
OCCLUSION MOVES IN FROM THE YUKON ON THURSDAY...BARROW EASTWARD
MIGHT SEE A CHANCE OF SNOW...MORE THAN FLURRIES.

THE WEST COAST...UPPER LOW WILL LEND SUPPORT TO DEVELOPING SURFACE
LOW IN NORTON SOUND TODAY WHICH SHOULD ENHANCE SPOTTY SNOW SHOWERS
ACROSS THE WEST COAST AND WESTERN INTERIOR. EVEN AS SURFACE LOW
MOVES NORTHWEST OVER THE THE NEXT FEW DAYS...COLD CORE ALOFT
SHOULD PROVIDE ENOUGH INSTABILITY TO KEEP SCATTERED TO ISOLATED
SNOW SHOWERS IN THE FORECAST AT LEAST THROUGH THURSDAY. MORE
MARINE AREAS LIKE SAINT LAWRENCE ISLAND AND THE YUKON DELTA MAY
SEE A LITTLE RAIN MIXED WITH SNOW AS AIR MASS MODERATES OVER THE
WARMER WATERS.

THE EXTENDED...A BERING SEA LOW WILL RUSH INTO SOUTHWESTERN ALASKA
ON THURSDAY INFLATING SNOW CHANCES FOR THE WEST COAST ON FRIDAY.
MEANWHILE...THE CLOSED LOW ON THE WEST COAST MOVES INLAND OVER THE
INTERIOR...ALLOWING A SLIGHT WARMING TREND FOR THE WEST COAST.
HOWEVER...THE WARMING TREND WILL BE TEMPERED WITH GREATER RAIN AND
SNOW CHANCES AS THE BERING SEA SETS UP FOR A PERIOD OF GREATER
FRONTAL ACTIVITY. ARCTIC AND INTERIOR WILL STAY COOL.

.AFG WATCH/WARNING/ADVISORIES...
PUBLIC...FREEZING RAIN ADVISORY...202
MARINE...GALE WARNING.............235...240...245
         FREEZING SPRAY WARNING...225...230...235...240...245
         SMALL CRAFT ADVISORY.....230

JWA OCT 05