Small Craft Advisory 1048, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
200 PM AKST MON DEC 29 2008

.MODEL DISCUSSION...MODEL INITIALIZATIONS REASONABLE. FORECAST TRENDS
ARE SIMILAR AND IN GENERAL AGREEMENT.

.ANALYSIS AND UPPER LEVELS...
BLOCKING PATTERN REMAINS IN PLACE WITH STRONG BERING SEA RIDGE AND
CUT-OFF LOW OVER THE GULF OF ALASKA. BLOCK WILL GENERALLY HOLD
THROUGH LATE THIS WEAK WITH SOME MODIFICATION AS CUT-OFF LIFTS NORTH
AS STRONG CENTER MOVES FROM THE ARCTIC OCEAN TO OVER SOUTHCENTRAL
ALASKA FRI. THIS LOW THEN BECOMES STATIONARY OVER THE WEEKEND AS
BERING SEA HIGH CENTER MOVES OVER NE RUSSIA.

.SHORT TERM FORECAST...
.EAST...HIGH PRESSURE BUILDS OVER THE MAINLAND AND LOW PRESSURE OVER
THE GULF SLOWLY WEAKENS. PRESSURE GRADIENTS ACROSS SOUTHCENTRAL WILL
MAINTAIN STRONG GAP/DRAINAGE FLOWS THROUGHOUT THE REGION THROUGH TUE.
NE WINDS OVER THE MAT VALLEY WILL BE ENHANCED SOME TONIGHT AS UPPER
FLOWS STRENGTHENS. WINDS SHOULD DIMINISH BELOW WARNING LEVELS TUE
MORNING AS THE SURFACE GRADIENT WEAKENS. VERY COLD DENSE AIR COMBINED
WITH STRONG PRESSURE GRADIENTS ALONG THE NORTH GULF COAST WILL
CONTINUE STRONG OUTFLOW WINDS THROUGH THE COPPER RIVER DELTA INTO
TUE AFTERNOON. MAY HAVE TO EXTEND WARNING THROUGH TUE NIGHT...FOR NOW
WILL CONTINUE WIND WARNING FOR THE COPPER RIVER DELTA THROUGH TUE
AFTERNOON. STRONG NORTH TO EAST WINDS LIKELY TO HOLD IN ZONE 131
THROUGH TUE MORNING. STRONG WIND HEADLINE SHOULD ADEQUATELY COVER
THIS ZONE AS THERE IS LITTLE UPPER SUPPORT FOR WARNING LEVEL WINDS.
ONLY CONSIDERATION WOULD BE ENHANCED SUBSIDENCE TONIGHT OVER THE
AREA.

COLD TEMPERATURES LIKELY TO CONTINUE OVER SOUTHCENTRAL THROUGH THIS
WEEK. GUSTY WINDS COMBINED WITH LOW TEMPS WILL SUSTAIN WIND CHILL
ADVISORIES FOR ZONES 141...145...AND 135 THROUGH TUE AFTERNOON AND
MAYBE THROUGH WED MORNING.

.WEST...
RIDGE CONTINUES TO BUILD OVER THE SOUTHWEST MAINLAND. GUSTY NORTH
WINDS WILL CONTINUE THROUGH TONIGHT AND SIGNIFICANTLY WEAKEN TUE
AFTERNOON/NIGHT AS RIDGE TAKES HOLD. COLD TEMPS WITH GUSTY WINDS ARE
CREATING LOCALLY LOW WIND CHILLS...HOWEVER VALUES SHOULD STAY ABOVE
ADVISORY LEVELS THROUGH TONIGHT. COLD TEMPS LIKELY TO CONTINUE OVER
THE MAINLAND THROUGH THIS WEEK...THOUGH THEY WILL MODERATE SOME WED
NIGHT AND THU AS CLOUD COVER INCREASES INLAND AS UPPER SHORT WAVE
DROPS ACROSS THE MAINLAND.

SNOW/SNOW SHOWERS OVER THE NORTH COAST OF THE AK PEN WILL CONTINUE
THROUGH TUE WAS COLD AIR FLOWING OFF THE SW MAINLAND PICKS UP
MOISTURE FROM OPEN WATER SOUTH OF THE ICE PAC. SNOW SHOWERS COMBINED
WITH WINDS ARE CAUSING LOCALLY POOR VISIBILITIES ALONG THE AK PEN IN
BLOWING SNOW. WINDS SHOULD DIMINISH OVER THE AREA TUE.

GUSTY EAST WINDS WILL CONTINUE ACROSS THE CENTRAL AND WESTERN
ALEUTIANS FOR THE NEXT COUPLE OF DAYS AS TROUGH OVER THE NORTH
PACIFIC BUMPS UP AGAINST THE BERING SEA RIDGE.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...HIGH WIND WARNING ZONES 111 135.
         HIGH WIND WATCH ZONE 131
MARINE...GALE 121 129 130 138 160 170 171 171 175 176
         HEAVY SPRAY 121 125 129 130 138 140 141 150 160 165 180 185
FIRE WEATHER...NONE.

RMC DEC 08