Small Craft Advisory 60, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM AST MON JAN 15 2007

.DISCUSSION...

MODELS IN GENERALLY GOOD SYNOPTIC AGREEMENT OUT THROUGH 60 HOURS.
GFS PREFERRED MODEL DUE ITS BETTER HANDLING OF MULTIPLE SMALL LOW
CENTERS OVER BERING SEA BEGINNING AT 36 HOURS.

AS OF 12Z...UPPER LEVELS ARE CHARACTERIZED BY A DEEP TROUGH FROM
BARROW TO THE SOUTHERN GULF AND BY A A FLAT NOSED RIDGE EXTENDING OUT
OF THE NORTH PACIFIC AND ACROSS THE EASTERN BERING SEA. DEVELOPING
H514 LOW NEAR 48N 177E WILL ALSO BE A PLAYER. BY 18Z TUE...UPPER LEVEL
TROUGH IS PROGGED TO HAVE RECEDED BACK UP INTO CHUKCHI SEA. RIDGE HAS
SHIFTED OVER MAINLAND ALASKA. AND A WELL DEVELOPED CUT OFF H506 LOW IS
ANCHORED OVER ADAK...AND REMAINS SO THROUGH 72 HOURS.

AT THE SFC...ALL MODELS STRUGGLING TO RESOLVE THE RESIDUAL LOW NEAR
PRINCE WILLIAM SOUND. BEST GUESS IS THAT THIS FEATURE WILL GRADUALLY
DISSOLVE INTO THE FAMILIAR NORTH GULF COAST TROUGH BY THIS EVENING.
TROUGH ITSELF DISSIPATES BY TUE MORNING. EXPECT CONTINUED GUSTY
NORTHWEST TO NORTHEAST WINDS THROUGH CHANNELED AREAS FROM WHITTIER TO
TO THE COPPER RIVER DELTA THROUGH TONIGHT. PRECIP WILL END BY LATE
THIS AFTERNOON. BLOWING SNOW AND REDUCED VISIBILITIES STILL AN ISSUE
FOR THOMPSON PASS THROUGH THIS MORNING.

BROAD STRATOCUMULUS DECK ACROSS SOUTHWEST ALASKA CONTINUES TO
GRADUALLY EXPAND. INFLUENCE OF UPPER LEVEL TROUGH IS ENOUGH TO PRODUCE
SPORADIC PERIODS OF SNOW BUT LITTLE ACCUMULATION IS EXPECTED.
PATTERN SHOULD PERSIST THROUGH MONDAY EVENING. GUSTY EAST WINDS IN
ADVANCE OF OCCLUDED FRONT EARLY TUESDAY SHOULD TEMPORARILY SCOUR OUT
THE AREA BEFORE NEXT JOLT OF PRECIP ARRIVES TUESDAY NIGHT.

PER THE GFS...THE LARGE 980 MB LOW 500 NM SOUTH OF ADAK WILL BECOME A
974 MB LOW APPROX 75 NM NORTH OF ATKA TUE NIGHT AND A COMPLEX LOW
CENTERED NEAR SAINT PAUL WED NIGHT. THE LOW THEN REMAINS NEARLY
STATIONARY THROUGH FRI AFTERNOON AS IT GRADUALLY WEAKENS TO 990 MB.

ASSOCIATED OCCLUDED FRONT WILL REACH THE CENTRAL ALEUTIANS THIS
MORNING...EASTERN ALEUTIANS AND PRIBILOFS THIS AFTERNOON... AND THE
ALASKA PENINSULA TONIGHT. THE FRONT IS EXPECTED TO WEAKEN
SUBSTANTIALLY AS IT MOVES ONSHORE TUE AFTERNOON. MAX GALES ALONG AND
IN ADVANCE OF THE FRONT. ALSO AMPLE PRECIPITATION IMMEDIATELY ALONG
THE FRONT. PRECIP FALLING AS A MIXTURE OF RAIN AND SNOW IMMEDIATELY
ALONG THE FRONT. SNOW SHOWERS IN THE WAKE OF THE FRONT.

LOOKING TOWARDS THE HORIZON...THE POTENTIAL DEVELOPMENT OF A TRIPLE
POINT LOW ALONG THE ABOVE MENTIONED OCCLUDED FRONT WILL BE THE ISSUE.
BEST GUESS AT THIS TIME IS THAT LOW WILL DEVELOP ALONG THE FRONT
AROUND 45N 155W SOMETIME TUE NIGHT. POTENTIAL FOR LOW TO TRACK DUE
NORTHWARD INTO THE NORTHERN GULF BY THU MORNING.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD 131.
MARINE...GALE 132 138 150 155 160 165 170 171 172 175 176 179 180 185.

FIRE WEATHER...NONE.

ASB JAN 07