Small Craft Advisory 1049, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
200 PM AST SUN NOV 12 2006

.DISCUSSION...

CURRENT FORECASTS ARE ON TRACK SO THERE WILL BE LITTLE CHANGE TO THE
FORECAST WITH THIS AFTERNOONS PACKAGE. WATER VAPOR IMAGERY SHOWS
UPPER LEVEL SHORT-WAVE TROUGH DROPPING SOUTHEASTWARD INTO THE COPPER
RIVER BASIN. COLD ADVECTION HAS BEGUN BEHIND THIS SHORT-WAVE FROM THE
KUSKOKWIM AND BRISTOL BAY TO THE SUSITNA VALLEY. 12Z SOUNDINGS FOR
ANCHORAGE...MCGRATH...AND KING SALMON SHOWED SIGNIFICANT TEMPERATURE
INVERSIONS. IT WILL TAKE A WHILE FOR WINDS TO ERODE THE INVERSION AND
MAKE IT INTO THE VALLEYS AROUND SOUTHERN ALASKA. THERE ARE ALSO AREAS
OF FOG AROUND THE REGION THAT WILL DISSIPATE AS THE WINDS INCREASE
LATER TODAY. THE SHORT-WAVE DOES NOT MOVE THROUGH EASTERN PRINCE
WILLIAM SOUND UNTIL LATE AFTERNOON AND EVENING. THEREFORE...WILL
NEED TO MOVE BACK THE STARTING TIMES OF HIGH WIND WARNINGS FOR ZONE
131 AND 135. OTHER THAN THAT...ONLY CHANGE TO SOUTHCENTRAL FORECAST
WILL BE SLIGHT CHANGES IN WINDSPEED FORECASTS.

A MYRIAD OF SHORT-WAVES EMBEDDED IN NORTHERLY FLOW COMBINED WITH
CHANGES IN STRENGTH OF EASTERN GULF SURFACE LOW WILL RESULT IN
OCCASIONAL FLUCTUATIONS IN THE STRENGTH OF THE WINDS ACROSS THE
REGION THE NEXT FEW DAYS. THE LARGEST BREAK APPEARS TO BE MONDAY
NIGHT AS A LOW DROPS INTO INTERIOR ALASKA. THIS IS WHEN HIGH WIND
WARNINGS ARE SET TO END. HOWEVER...WINDS WILL PICK BACK UP AGAIN BY
TUESDAY AFTERNOON AS UPPER SHORT-WAVE DROPS INTO THE GULF HELPING TO
DEEPEN EASTERN GULF LOW WHILE ANOTHER SURGE OF COLD AIR MOVES DOWN
FROM THE NORTH. WILL LIKELY NEED TO RE-ISSUE HIGH WIND WARNINGS FOR
VALDEZ AND THE COPPER RIVER DELTA TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT...BUT WILL WAIT UNTIL WE GET THIS FIRST WARNING EVENT STARTED
SO AS NOT TO CONFUSE THE SITUATION. BY WEDNESDAY THERE WILL BE A
HUGE CYCLONIC CIRCULATION OVER THE GULF AND SOUTHERN MAINLAND. AT
THAT POINT WILL NEED TO WATCH FOR THE POTENTIAL OF SNOW AS
SHORT-WAVES ROTATE WESTWARD ACROSS SOUTHCENTRAL AND SOUTHWEST ALASKA.

ASIDE FROM THE COLD ADVECTION WINDS THE OTHER FEATURE OF CONCERN IN
THE SHORT-TERM IS A SHORT-WAVE DROPPING DOWN ACROSS WESTERN ALASKA
TONIGHT AND ACROSS BRISTOL BAY AND THE AKPENN MONDAY. MODEL SOLUTIONS
HAVE CHANGED SLIGHTLY THE PAST FEW RUNS SO THERE CONTINUES TO BE
SMALL ALTERATIONS TO THE PLACEMENT OF PRECIPITATION WITH THIS
FEATURE. WITH RAPID MOVEMENT AND LIMITED MOISTURE EXPECT SNOWFALL
AMOUNTS TO BE LIGHT. THERE WILL BE SOME BLOWING SNOW AS WELL...BUT
IT CONTINUES TO LOOK LIKE THE SNOWFALL AND STRONG WINDS WILL NOT
COINCIDE. THERE IS STILL SOME CONCERN ABOUT THE NORTH COAST OF THE
AKPENN FROM ABOUT PORT HEIDEN WESTWARD MONDAY AFTERNOON...BUT WILL
WAIT ONE MORE MODEL RUN BEFORE MAKING FINAL DECISION ON WHETHER
VISIBILITIES WILL REACH AS LOW AS 1/4 MILE. EXPECT STRONG GALES
WEST OF THIS SHORT-WAVE WITH STORM FORCE GUSTS OUT OF BAYS AND
PASSES OF THE ALASKA PENINSULA.

OUT WEST...HIGH AND DRY AS THE BLOCKING RIDGE HOLDS STEADY.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...HIGH WIND WARNING ZONE 131 AND 135.
MARINE...GALE WARNING 120 121 125 130 132 138 140 150 155 160 165 170
180.

SEB