Storm Warning 42, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
227 PM AKST WED NOV 4 2009

.SHORT TERM...VERY ACTIVE WEATHER DAY WITH A STORM FORCE LOW IN
THE WESTERN GULF THAT WILL CONTINUE TO INTENSIFY OVERNIGHT AS IT
TRACKS INTO THE CENTRAL GULF. WIND ADVISORIES IN PLACE FOR ZONES
22...26 AND 29. HIGH WIND WARNINGS NOW IN PLACE FOR THE OUTER
COAST FROM CAPE EDGECUMBE SOUTH AS WELL AS ZONE 28. ALSO HAVE
COASTAL FLOOD ISSUES ASSOCIATED WITH STORM WINDS...STORM
SURGE...AND A SWELL TRAINS THAT WILL BECOME MORE SOUTHWESTERLY
WITH TIME. COASTAL MARINE ZONES AS WELL AS CLARENCE STRAIGHT NOW
INCLUDE STORM WARNINGS FOR TONIGHT AND EARLY TOMORROW. GALES
ELSEWHERE. SEE VARIOUS WARNING AND ADVISORY STATEMENTS AS WELL AS
THE ROUTINE FORECAST PRODUCTS ISSUED BY THIS OFFICE FOR
ADDITIONAL SHORT TERM FORECAST DETAILS.

.LONG TERM...LONG RANGE PATTERN REMAINS SIMILAR TO THE PREVIOUS
PACKAGE AND MOST EMPHASIS WAS PLACED ON THE FORECAST NEAR HAND OFF
WITH SHORT TERM AS THE STORM FORCE LOW CURRENTLY IN THE GULF WILL BE
GRADUALLY FILLING AND WEAKENING THROUGH SATURDAY AS IT MOVES
SLOWLY INTO THE NORTHERN GULF. BLENDED INHERITED GRIDS TOWARD A
12Z NAM/ECMWF BLEND THROUGH SATURDAY MORNING AS BOTH THESE MODELS
GAVE THE BEST REPRESENTATION OF THE SURFACE PRESSURE GRADIENT
THROUGH THE WEEKEND. THE 12Z GFS THROUGH THE WEEKEND DISSIPATES THE
STORM FORCE LOW OVER THE CHUGACH MOUNTAINS RATHER THAN IN THE
NORTHERN GULF. DAY 3 ONWARD BLEND TOWARD THE 12Z ECMWF AND HPC SOLUTION
WHICH WAS A LITTLE MORE AGGRESSIVE BRINGING A GALE FORCE LOW
NORTHWARD ALONG THE OUTER COAST MONDAY AND TUESDAY...WHICH HAS
RECENT MODEL RUN TO RUN CONSISTENCY BOTH IN THE 12Z GFS AND ECMWF
AS WELL AS THE NAEFS ENSEMBLE.

AFTER HAND OFF WITH SHORT TERM WILL CONTINUE TO SEE NEAR ADVY WIND
GUSTS ALONG THE OUTER COAST AS ANOTHER GALE FORCE FRONTAL BAND
WILL MOVE NORTHEASTWARD ACROSS THE PANHANDLE. WILL HAVE TO MONITOR
THE NEXT SET OF MODEL RUNS FOR THE POTENTIAL OF WIND ADVY GUSTS
OUT OF THE SOUTHWEST THURSDAY NIGHT AND FRIDAY. OTHERWISE WINDS
WILL REMAIN LOCALLY BREEZY THROUGH SATURDAY ESPECIALLY NEAR EAST- WEST
ORIENTED CHANNELS. PERIODS OF RAIN WILL SPREAD NORTHWARD ACROSS
THE PANHANDLE THROUGH THE WEEKEND WITH THE HEAVIEST RAINFALL
REMAINING ALONG THE SOUTHERN PANHANDLE WITH THE BETTER UPPER LEVEL
JET SUPPORT. BY EARLY NEXT WEEK THE 12Z MODELS DEVELOP ANOTHER
GALE FORCE LOW MOVING INTO THE SOUTHEASTERN GULF AND THERE HAS
BEEN MORE RUN TO RUN CONSISTENCY WITH THIS SOLUTION. THE LONG WAVE
TROUGH WILL REMAIN IN THE GULF THROUGH EARLY NEXT WEEK SO THE GALE
FORCE LOW SOLUTION DOES HAVE CREDIBILITY IN THE LONG WAVE PATTERN.
AFTER NEXT WEDNESDAY MODEL SOLUTIONS DIVERGE SIGNIFICANTLY ON WHERE
A DEVELOPING ARCTIC AIRMASS IN SIBERIA WILL MOVE. WILL HAVE TO
CONTINUE TO MONITOR THE LONG RANGE MODELS TO SEE IF THIS ARCTIC
AIR MASS ADVECTS INTO THE PANHANDLE LATE NEXT WEEK.

FORECAST CONFIDENCE IS ABOVE AVERAGE THROUGH THE WEEKEND UNTIL
MODELS DIVERGE ON THE POSITION OF THE GALE FORCE LOW NEAR THE
OUTER COAST MONDAY AND TUESDAY. HOWEVER...MODEL SOLUTIONS ARE IN
MUCH BETTER AGREEMENT THIS AFTERNOON THAN YESTERDAY. WINDY AND
RAINY CONDITIONS WILL CONTINUE THROUGH THE WEEKEND ACROSS THE
PANHANDLE WITH THE RAIN/SNOW LINE RETREATING INTO THE YUKON.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...WIND ADVISORY UNTIL 6 PM AKST THURSDAY FOR AKZ022-026-029.
...HIGH WIND WARNING UNTIL 6 PM AKST THURSDAY FOR AKZ023-027-028.
...WIND ADVISORY UNTIL 4 PM AKST THIS AFTERNOON FOR AKZ023-027-028.
...COASTAL FLOOD WARNING UNTIL 4 PM AKST THURSDAY FOR AKZ023-027.

MARINE...STORM WARNING FOR PKZ036-043-052.
...GALE WARNING FOR PKZ011>013-021-022-032>035-041-042-051.
...SMALL CRAFT ADVISORY FOR PKZ031.
...MARINE WEATHER STATEMENT FOR PKZ036.

&&

FRITSCH/PSS