Small Craft Advisory 959, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
220 PM AST TUE NOV 13 2007

.MODEL DISCUSSION...SHORT TERM FORECAST FAIRLY SIMILAR. THERE ARE
STILL LARGE DIFFERENCES IN THE LONG TERM. WILL CONTINUE TO LEAN
TOWARD THE GFS AND ONLY MAKE MINOR CHANGES BEYOND THU AFTERNOON.

.ANALYSIS...
REMNANT OF FRONTAL TROUGH EXTENDING FROM THE SUSITNA VALLEY TO ALONG
THE NORTH GULF COAST WILL MOVE INTO THE INTERIOR TONIGHT. A 980S LOW
OVER BRISTOL BAY IS STACKED AND WILL SLOWLY WEAKEN AS IT MOVES SOUTH
OF KODIAK ISLAND WED NIGHT/THU AM. ASSOCIATED FRONTAL TROUGH OVER THE
KENAI PEN THIS AFTERNOON MOVES INTO THE SUSITNA VALLEY/COPPER RIVER
BASIN THROUGH TONIGHT. A SECONDARY LOW CENTER LIKELY WILL FORM ALONG
THE BROAD FRONTAL BOUNDARY SOUTH OF THE AK PEN AS UPPER TROUGH DIGS
AND FAVORABLE UPPER JET POSITION SETUP. THE NAM PICKS UP THIS FEATURE
BETTER THEN THE GFS. LOW IS FORECAST TO MOVE SOUTH OF THE KENAI PEN
WED AFTERNOON WHERE IT THEN STALLS AS BRISTOL BAY LOW DROPS SOUTH OF
KODIAK. WITH TIME A STRONG LOW CENTER MOVES INTO THE EASTERN GULF OF
ALASKA FRI AFTERNOON AND FLOW OVER THE CENTRAL AND WESTERN GULF
SHIFTS OFFSHORE.

A HIGH PRESSURE RIDGE BUILDING OVER THE WESTERN BERING SEA TODAY
MOVES TO THE CENTRAL BERING SEA/ALEUTIAN ISLANDS THU MORNING. THE
RIDGE THINS AND IS PINCHED OFF NORTH OF SAINT MATTHEW ISLAND AND
SOUTH OF THE EASTERN ALEUTIANS LATE FRI. A FRONTAL TROUGH MOVES TO
THE WESTERN ALEUTIANS FRI MORNING AND THE EAST/CENTRAL ALEUTIANS FRI
NIGHT AS TRIPLE POINT FORMS SOUTHEAST OF ADAK. THIS SEEMS REASONABLE
WITH STRONG NPAC JET SOUTH OF THE ALEUTIANS.

.SURFACE...
.EAST...SNOW WILL DIMINISH OVER SOUTHCENTRAL OVERNIGHT WITH PASSAGE
OF FRONTAL TROUGH. EXCEPT SNOW WILL LINGER INTO WED MORNING OVER THE
NORTHERN SUSITNA/COPPER RIVER UNTIL FRONT CLEARS THE REGION. EXPECT
RAIN AND SNOW ALONG THE NORTH GULF COAST SHOULD SHIFT TO SHOWERS
OVERNIGHT. CONCERNS WOULD BE WITH SNOW POTENTIAL FOR THE WEST/NORTH
GULF AND EASTERN KENAI PEN AS A SECONDARY LOW MOVES SOUTH OF THE
KENAI PEN WED AFTERNOON/EVENING. EXPECT SNOW VALUES FOR THESE AREAS
COULD BE SIGNIFICANT AS LOW TAPS INTO MOISTURE OVER THE GULF. MODELS
THEN WARM TEMPS UP ALONG THE NORTH GULF COAST/KENAI PEN WED
NIGHT/THU...SO MAY SEE SOME AREAS SHIFT OVER THE RAIN OR MIX.
850/700MB FLOWS SHIFT MORE E-NE ON THU NIGHT...SO SHOULD SEE SOME
DRYING CONDITIONS WITH PERHAPS GUSTY GAP WINDS ALONG THE NORTH GULF
AND PORTIONS OF SOUTHCENTRAL.

.WEST...TEMPS WILL CONTINUE TO COOL OVER BRISTOL BAY TONIGHT...SO
WILL SEE SNOW SHOWERS OVER MUCH OF SW ALASKA AND EASTERN BERING SEA
THROUGH WED AFTERNOON. GENERAL DRYING CONDITIONS ARE EXPECTED OVER
THE SW MAINLAND WED NIGHT AS SYNOPTIC FLOWS SHIFTS OFFSHORE AND
BRISTOL BAY LOW MOVES SE. GUSTY WINDS WITH SNOW SHOWERS LIKELY TO
HOLD OVER THE EASTERN BERING SEA/AK PEN THROUGH FRI NIGHT. EXPECT NW
WINDS TO DIMINISH SAT. RAIN/SNOW AND BRISK SOUTHERLY WINDS WILL
SPREAD TO THE WESTERN ALEUTIANS WITH FRONTAL TROUGH THU NIGHT.
RAIN/SNOW WILL SPREAD TO THE EAST/CENTRAL ALEUTIANS WITH THIS SYSTEM
FRI EVENING. EXPECT GUSTY WEST WINDS ALONG THE BACK SIDE OF FRONT.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALES 120 155
FIRE WEATHER...NONE.

RMC NOV 07