High Wind in Alaska, November 22, 2012

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
529 AM AKST THU NOV 22 2012

.SHORT TERM...SATEELLITE IMAGERY IS SHOWING AN IMPRESSIVE
DEVELOPING SYSTEM MOVING INTO SOUTHERN GULF OF ALASKA. THE
WEATHER FRONT AND THE BAND OF VERY STRONG WINDS WILL BE SPREADING
INTO THE SOUTHERN PANHANDLE THU MORNING AND NORTH INTO THE
NORTHERN PANHANDLE BY THU NIGHT. STRONG STORM FORCE WINDS ARE
EXPECTED ACROSS THE SOUTHERN OUTER WATERS AND THE OFF SHORE
WATERS FOR THIS MORNING. OTHER STORM FORCE WINDS ARE EXPECTED IN
THE SOUTHERN INNER CHANNELS AND CROSS SOUND...ALSO WITH A NORTH
OUTFLOW IN NORTHERN LYNN CANAL.

 THE PRECIPITATION BAND IS EXPECTED TO ME MAINLY ONLY ABOUT A FEW
HOURS LONG WITH THE INITIAL FRONT. AM EXPECTING A RAIN OVER TH
SOUTHWESTERN PANHANDLE THEN TRANSITION TO A MIX OR SNOW FOR THE
CENTRAL TO NORTHERN PANHANDLE. AM ONLY EXPECTING A FEW INCHES OF
SNOW OVER NORTHERN PANHANDLE WITH THE FRONT.

 TOWARDS THE END OF THE TONIGHT PERIODS THE FRONTAL BAND THAT HAS
WRAPPED AROUND THE LOW WILL BE MAKING A SECOND APPROACH BY
SUNRISE ON FRIDAY.

 THE HIGH WIND WARNINGS FOR THE SOUTHERN PANHANDLE ARE STILL ON
TRACK, WITH THE FRONTAL BAND. IN THE DOWNTOWN JUNEAU AND DOUGLAS
ISLAND REGION, STILL LOOKING LIKE THE TAKU WINDS WILL PICK UP
THIS MORNING THROUGH THE EARLY EVENING.

 &&

 .LONG TERM...THE THURSDAY STORM FORCE LOW WILL CONTINUE TO
WEAKEN THROUGH FRIDAY AS IT APPROACHES THE SOUTHERN PANHANDLE
COAST. THE LOW CENTER FILL HAVE FILLED TO AROUND 972 MB BY 15Z
FRIDAY AND CONTINUE TO WEAKEN TO 994 MB WITH IN 24 HOURS. THE LOW
CENTER WILL MOVE ONSHORE JUST SOUTH OF CAPE DECISION BY SATURDAY
AFTERNOON. THE LOW WILL QUICKLY MOVE ACROSS THE SOUTHERN
PANHANDLE AND INTO BRITISH COLUMBIA SATURDAY EVENING. MEANWHILE
HIGH PRESSURE OVER THE YUKON WHILE BUILD THROUGH SATURDAY
EVENING.

 WINDS FROM THE SECONDARY WRAP WILL HIT THE SOUTHERN COASTAL
WATERS AND PANHANDLE FRIDAY MORNING WITH 850 MB WINDS AROUND
60 KTS. STRONG WINDS EXPECTED TO CONTINUE FOR THE CENTRAL AND
SOUTHERN PANHANDLE WITH GUSTS TO 50 MPH. STRONG WINDS OVER THE
NORTHERN PANHANDLE WILL REMAIN DUE TO PRESSURE GRADIENT BETWEEN
THE YUKON HIGH AND PANHANDLE LOW.

 PRECIPITATION FROM THE LOW FROM FRIDAY TO SATURDAY LOOKS TO
MAINLY BE SOUTH OF ICY STRAIT. ARCTIC BOUNDARY AS SEEN FROM TIGHT
THERMAL GRADIENT BETWEEN THE YUKON AND SOUTHERN PANHANDLE WILL
NOT ONLY KEEP THE PRECIP TO THE SOUTH BUT ALSO INDICATED THE
DIVIDING LINE BETWEEN SNOW..NORTH OF ICY STRAIT...A RAIN SNOW MIX
NORTH IF FREDERICK SOUND...AND ALL RAIN SOUTH OF FREDERICK SOUND.
THIS TEMPERATURE DIVISION WILL LAST THROUGH SUNDAY EVENING.

 A RIDGE OF HIGH PRESSURE WILL BUILD OVER THE CENTRAL AK GULF
SATURDAY EVENING AND WILL MOVE INTO THE EASTERN GULF BY SUNDAY
FINALLY TRACKING OVER THE PANHANDLE SUNDAY NIGHT. WILLS OVER THE
GULF AND PANHANDLE WILL DIMINISH SIGNIFICANTLY THROUGH THE TIME
FRAME. ONSHORE FLOW WILL KEEP A CHANGE OF PRECIP OVER THE
SOUTHERN PANHANDLE WHILE A DRYING TREND OCCURS TO THE NORTH. WITH
ARCTIC HIGH STILL OVER THE YUKON WILL SEE COLDER AIR BEGIN TO
PUSH FURTHER SOUTH.

 AT 06Z MONDAY BEHIND THE RIDGE MODELS ARE HAVING TROUBLE
RESOLVING THE NEXT LOW PRESSURE SYSTEM...MAINLY HOW ONE SYSTEM
MOVING UP FORM THE NORTH PACIFIC WILL INTERACT WITH A SECOND LOW
MOVING JUST SOUTH OF THE ALEUTIAN CHAIN. BY MID WEEK THE NEXT
SYSTEM LOOKS TO RESIDE OVER THE SOUTHERN AK GULF BUT FAR TOO MUCH
UNCERTAINTY AT THIS TIME.

 MODELS WERE STILL IN GOOD AGREEMENT FRIDAY. BY SATURDAY
DIFFERENCES BEGIN TO EMERGE. RMOP VALUES AND ENSEMBLE SPREAD
BECOME FAIRLY LARGE THROUGH DAY 8. 06Z NAM BECAME MORE OF AN
OUTLIER MOVING THE LOW CENTER BIT FURTHER NORTH TOWARD SITKA BY
12Z SAT. THE 00Z GFS SHOWS THE LOW WEAKENING FASTER THAN THE 00Z
ECMWF BY 5 TO 6 MB BUT MODELS WERE STILL IN GOOD AGREEMENT WITH
THE POSITION OF THE LOWS CENTER THROUGH THIS TIME. USED A BLEND
OF 00Z GFS AND ECMWF TO REFRESH INHERITED GRIDS THROUGH DAY 4.
TRANSITIONED TO HPC GUIDANCE FOR THE REMAINDER OF THE LONG RANGE.
MAIN CHANGES WERE WINDS IN THE AK GULF FOR THE EXTENDED PERIOD.
USED MORE OF AN ENSEMBLE BLEND FOR THIS TIME DUE TO THE LARGER
MODEL SPREAD. FORECAST CONFIDENCE IS AVERAGE THROUGH SATURDAY BUT
DROPS BY THE START OF TH WEEK DUE TO INCREASED MODEL SPREAD.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...HIGH WIND WARNING FROM 9 AM THIS MORNING TO 6 PM AKST THIS
     EVENING FOR AKZ026-028.
         HIGH WIND WARNING FROM 9 AM THIS MORNING TO 3 PM AKST THIS
     AFTERNOON FOR AKZ023-025-027.
         STRONG WIND UNTIL 9 AM AKST THIS MORNING FOR AKZ027.
         STRONG WIND FROM 3 PM AKST THIS AFTERNOON THROUGH LATE TONIGHT
     FOR AKZ020-023-027.
         STRONG WIND FROM 3 PM AKST THIS AFTERNOON THROUGH LATE TONIGHT
     FOR AKZ017-025.
         STRONG WIND FROM 9 AM AKST THIS MORNING THROUGH LATE TONIGHT FOR
     AKZ019-022.
         STRONG WIND UNTIL 9 AM AKST THIS MORNING FOR AKZ023.
         STRONG WIND THIS EVENING FOR AKZ028.
         STRONG WIND FROM 9 AM THIS MORNING TO 3 PM AKST THIS AFTERNOON
     FOR AKZ029.
         STRONG WIND THIS EVENING FOR AKZ029.
         STRONG WIND THROUGH LATE TONIGHT FOR AKZ018.
MARINE...STORM WARNING FOR PKZ011>013-021-022-033-036-041>043.
         GALE WARNING FOR PKZ031-032-034-035-051>053.

&&

BEZENEK/PRB