Gale Warning 231, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
130 PM AKDT FRI SEP 25 2009

.SHORT TERM...THE REMAINS OF THE PARENT LOW NEAR PRINCE WILLIAM
SOUND WILL CONTINUE TO TRACK NORTHEAST AND JUMP INLAND. A WEAK
TROUGH WILL BE MOVING ACROSS THE PANHANDLE FRIDAY EVENING FROM
EASTERN GULF...AND THE LAST UPPER LEVEL (COLD) TROUGH WILL MOVE
ACROSS THE CENTRAL GULF AND TO THE COASTAL AREA SATURDAY MORNING
AND INLAND BY SATURDAY AFTERNOON. A WEAK SURFACE RIDGE WILL BE
BUILDING OVER THE GULF SATURDAY.

 ON THE SOUTH SIDE OF LOW NEAR PRINCE WILLIAM SOUND A BRISK WEST
WINDS ACROSS THE CENTRAL GULF WILL LAST ROUGHLY 18 TO 24 HOURS OF
STRONG GALE TO MIN STORM STRENGTH WILL BUILD A LARGE FOLLOWING
SEA UP TO 25 FEET THAT WILL TRAVEL INTO THE EASTERN GULF WATERS
FOR SATURDAY AND CONTINUE INTO SATURDAY EVENING. THE GUSTY WINDS
COULD ALSO BRINGS WIND GUSTS UP TO 35 KT FOR EXPOSED CAPES OF
BRANIFF AND PRINCE OF WALES ISLAND.

 WILL BE ISSUING STORM WARNING FOR MARINE ZONE 310 BUT
ESSENTIALLY FOR THE EXTREME CENTRAL GULF PORTION REST OF THE AREA
WILL BE 40 TO 45 KT AND ONCE STORMS SUBSIDE EXPECT THE STRONG
GALES TO PERSIST.

 GUSTY WINDS IN THE CANAL OVER NIGHT WILL HAVE A WIND ADVISORY
LEVEL GUSTS IN THE SKAGWAY AREA.

&&

.LONG TERM...MEDIUM RANGE MODELS ARE IN GENERAL AGREEMENT THROUGH
OUT THE LONG TERM PERIODS. THE NAM IS A LITTLE SLOWER AND MORE
AMPLIFIED THAN THE OTHER MODELS THROUGH EARLY NEXT WEEK. IN
GENERAL...HOWEVER...MODELS KEPT PRETTY GOOD CONSISTENCY FROM THE
PREVIOUS RUN. A SHORTWAVE TROUGH MOVING INTO THE CENTRAL GULF
LATE SATURDAY NIGHT WILL KEEP ITS SOUTHERN TRACK TO SOUTH OF THE
QUEEN CHARLOTTES BY LATE SUNDAY NIGHT. A RIDGE WILL RAPIDLY BUILD
BEHIND THE TROUGH ACROSS THE WESTERN AND CENTRAL GULF THROUGH
MONDAY NIGHT AND MOVE INTO THE EASTERN GULF BY TUESDAY. THE NEXT
SHORTWAVE TROUGH IN UPSTREAM OVER THE WESTERN ALASKA WILL PUSH THE
RIDGE EASTWARD AND FLAT DOWN THE RIDGE TOP BY EARLY WEDNESDAY
MORNING. THE ECMWF IS ABOUT 6 TO 12 HOURS FASTER WITH THE
PROGRESSION OF THE TROUGH APPROACHING TO THE EASTERN GULF AND
PANHANDLE COAST. BEGINNING ON LATE THURSDAY...MODELS DIVERGE A
LITTLE MORE WITH THE INTENSITY OF THE PROGRESSIVE TROUGH MOVING
ACROSS THE EASTERN GULF AND SOUTHEAST ALASKA. THUS OPTED TO BLEND
THE EXISTING GRIDS WITH THE GFS AND NAM THROUGH MONDAY MORNING
TIME FRAME FOLLOWED BY THE GFS SOLUTION INTO THE INHERITED GRIDS
THROUGH THE END OF THE PERIOD.

 A FRONT ASSOCIATED WITH A LOW DRIFTING SOUTHEASTWARD ACROSS THE
CENTRAL AND SOUTHEASTERN GULF THROUGH SUNDAY WILL MOVE TO THE
BRITISH COLUMBIA COAST BY MONDAY MORNING THEN NORTHEASTWARD
FARTHER INLAND THROUGH TUESDAY. A RIDGE BEHIND THE TROUGH WILL DRY
OUT THE PANHANDLE FROM THE NORTHWEST BEGINNING LATE SUNDAY NIGHT.
RAIN FREE CONDITION WILL QUICKLY SPREAD SOUTHEASTWARD ALL THE WAY
TO THE QUEEN CHARLOTTES BY MONDAY MORNING THEN PERSIST THROUGH
MONDAY NIGHT...IN WHICH TIME THE NEXT FRONT APPROACHING THE
NORTHEAST GULF WITH INCREASING CLOUDINESS AND CHANCE POPS FROM THE
WEST, THE TRANSITION WILL ALSO BE A QUICK PROCESS BEGINNING ON
EARLY TUESDAY MORNING OVER THE YAKUTAT AREA IN THE NORTH AND
ACROSS THE KETCHIKAN AREA TO THE SOUTH...THEN SPREAD EAST TO COVER
ENTIRE PANHANDLE. THE FRONT WILL INTENSIFY A BIT ON WEDNESDAY
NIGHT AND THURSDAY FOLLOWED BY TYPICAL SOUTHEAST ALASKA WET
PATTERN THROUGH FRIDAY. LONG PERIOD SOUTHWEST TO WEST SWELLS WILL
MAINTAIN SMALL CRAFT SEAS ACROSS THE ENTIRE OUTSIDE WATERS THROUGH
THE MIDDLE OF NEXT WEEK ALONG WITH SMALL CRAFT WINDS ACROSS THE
SOUTHERN HALF OF THE OUTSIDE WATERS. THE FRONTAL BOUNDARY
APPROACHING THE PANHANDLE COAST LATE MONDAY NIGHT WILL GENERATE
SMALL CRAFT WINDS AS WELL ACROSS THE SOUTHERN INNER CHANNELS AND
OCEAN ENTRANCES.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...WIND ADVISORY FROM 9 PM THIS EVENING TO 6 AM AKDT SATURDAY FOR
     AKZ018.
MARINE...GALE WARNING FOR PKZ033-041>043-051-052.
         SMALL CRAFT ADVISORY FOR PKZ012-021-022-031-032-034>036-053.

&&

BEZENEK/AHN