Gale Warning 334, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
156 PM AKST TUE NOV 3 2009

.SHORT TERM...SATELLITE IMAGERY THIS MORNING IS REVEALING TWO
SIGNIFICANT LOW PRESSURE CENTERS WHICH WILL CONSTITUTE THE NEXT
MAJOR WIND EVENT FOR THE PANHANDLE. TO THE SOUTH...A RAPIDLY
DEVELOPING LOW IS TRACKING NORTH JUST WEST OF 140W AND IS BEING
SUPPORTED BY A 180KT DESCENDING JET MAX TO THE WEST AND A 120KT
ASCENDING JET MAX TO THE EAST. FARTHER WEST...A FULLY OCCLUDED
LOW OVER BRISTOL BAY WILL TRACK SOUTHEAST OVER THE ALASKA
PENINSULA LATER TODAY. THIS LOW IS BEING MAINTAINED BY THE SAME
DESCENDING JET MAX SUPPORTING THE FIRST LOW. A VERY COMPLICATED
SURFACE PICTURE ENSUES AS THIS PAIR OF LOWS BEGINS TO MERGE AND
THEN ARE JOINED BY A THIRD WHICH ALSO ARRIVES FROM THE SOUTH
ALONG 140W LATE WEDNESDAY.

SOUTHEASTERLY WINDS STEADILY RAMP UP THROUGH THE DURATION OF THE
SHORT RANGE FORECAST BEGINNING TONIGHT OVER THE MARINE ZONES AND
HAVE WIND ADVISORIES SPREADING UP THE OUTER COAST BEGINNING
TOMORROW MORNING. AT THIS POINT...IT LOOKS LIKE ADVISORIES FOR THE
INNER ZONES WILL BE LIMITED TO ZONES 26 AND 28 WITH GALES OVER THE
SOUTHERN INNER CHANNELS AND NORTHERN LYNN CANAL. ELSEWHERE BREEZY
TO WINDY CONDITIONS WITH NORTHERLY/EASTERLY LOW LEVEL WIND FLOW.

WENT WITH CATEGORICAL POP FOR ALL LOCATIONS AS THE FRONT LIFTS
NORTH THROUGH THE DAY TOMORROW. AMSU DATA INDICATING THAT BOTH OF
THE LOWS DISCUSSED CURRENTLY HAVE TROPICAL MID LEVEL MOISTURE
CONNECTIONS. BUT THIS LINK LOOKS LIKE IT IS BEGINNING TO WEAKEN
AND CORRESPONDING 6-HOURLY QPF VALUES OVER LAND GENERALLY LIMITED
TO LESS THAN ONE QUARTER OF AN INCH THROUGH TOMORROW. LOCALLY
HIGHER AMOUNTS NEAR HIGHER TERRAIN.

THE ASSOCIATED FRONT WILL USHER IN WARMER LOW LEVEL AIR AND SNOW
AT LOWER LEVELS NOT TOO MUCH OF A CONCERN AT THIS TIME. DO HAVE A
LITTLE SNOW IN THE FORECAST FOR THE NORTHERN INNER CHANNELS AS
WELL AS YAKUTAT...BUT OVERNIGHT ACCUMULATION LIMITED TO LESS THAN
1 INCH.

OFFSHORE SEAS WILL BE BUILDING STEADILY THROUGH THE PERIOD WITH
AS MUCH AS 19 FEET IN THE SEAWARD HALF OF THE COASTAL MARINE ZONES
BY TOMORROW AFTERNOON. SWELL DIRECTION THROUGH TOMORROW GENERALLY
WILL REMAIN OUT OF THE SOUTHEAST...SO STORM SURGE IN CONJUNCTION
WITH DAILY HIGH TIDES FOR LOCATIONS SUCH AS SITKA AND YAKUTAT ONLY
RUNNING ABOUT A FOOT ABOVE THE ASTRONOMICAL HIGH TIDES. POTENTIAL
EXISTS FOR STORM SURGE TO INCREASE SIGNIFICANTLY WHEN THE SWELL
TRAIN BECOMES MORE SOUTHWESTERLY LATER THIS WEEK.

USED NAM AS PRIMARY GUIDANCE FOR PRESSURE...WIND...AND POP. USED
GFS FOR TEMPERATURE GUIDANCE. FORECAST CONFIDENCE ABOVE AVERAGE
THROUGH THE SHIRT TERM PERIOD.

.LONG TERM...THE UNSETTLED WEATHER PATTERN CONTINUES INTO THIS
WEEKEND AND THE 12Z OPERATIONAL AND ENSEMBLE MODELS OFFER NO
CONSENSUS SOLUTION TO THE MID RANGE WEATHER PATTERN. NEAR HAND OFF
WITH SHORT TERM THE LONG WAVE UPPER LEVEL TROUGH WILL AGAIN DIG
INTO THE GULF AND REMAIN THERE THROUGH FRIDAY AND THIS WILL LEAD
TO A GOOD CHANCE OF RAIN THROUGH THE WEEKEND. THE MAIN FORECAST
PROBLEM REMAINS THE WINDS ASSOCIATED WITH THE STORM TO GALE FORCE
949 MB LOW THAT WILL STRENGTHEN AS IT MOVES INTO THE CENTRAL GULF
BY THURSDAY AFTERNOON. BLENDED INHERITED GRIDS TOWARD A 12Z
NAM/ECMWF SOLUTION WITH THIS STRONG LOW THROUGH FRIDAY AS THE 12Z
GFS WAS AN OUTLIER SOLUTION BOTH IN POSITION AND STRENGTH. THE 12Z
GFS OVER PHASES ALL THE MID LEVEL ENERGY INTO ONE SURFACE LOW IN
THE GULF BY THURSDAY AFTERNOON. HOWEVER...THE SURFACE LOW NOW NEAR
40N 138W WILL MOVE NORTHWARD THROUGH THE SHORT TERM PERIOD THEN
DUMBBELL AROUND THE STRONGER 949 MB SURFACE LOW AND MOVE INTO THE
WESTERN GULF. WITH THE LONGWAVE TROUGH REMAINING ANCHORED IN THE
GULF THROUGH FRIDAY PREFERRED THE MODEL SOLUTIONS WITH MULTIPLE
SURFACE LOWS ROTATING CLOCKWISE AROUND IN THE GULF. AFTER DAY 4
MADE NO CHANGES TO MOST OF THE GRIDS AS THE 12Z GFS, NAEFS AND
ECMWF OPERATIONAL AND ENSEMBLE MODELS GAVE NO CONSENSUS SOLUTION
AND WERE ALSO NOT CONSISTENT WITH THEIR 00Z RUNS. THE 12Z HPC
SOLUTION WAS VERY SIMILAR TO INHERITED GRIDS THEREFORE SPENT MOST
OF THE TIME COORDINATING WITH SHORT TERM ON THE WINDY CONDITIONS
ACROSS THE PANHANDLE WEDNESDAY INTO THURSDAY.

NEAR HAND OFF WITH SHORT TERM THE SURFACE LOW IN THE SOUTH CENTRAL
GULF WILL CONTINUE TO SLOWLY MOVE NORTHWARD AND DEEPEN TO 949 MB.
THERE WILL BE AT LEAST TWO ADDITIONAL 850 MB LLJ WIND MAXIMA THAT
WILL ROTATE THROUGH THE EASTERN GULF AND NORTHWARD ACROSS THE
PANHANDLE THROUGH THURSDAY AFTERNOON. WITH THE ALREADY VERY STRONG
EAST-WEST ORIENTED SURFACE PRESSURE GRADIENT ACROSS THE PANHANDLE
CONTINUED THE WIND ADVY FROM THE SHORT TERM THROUGH THURSDAY. WILL
SEE WINDS BRIEFLY DROP BELOW ADVY GUSTS FOR 3 HOURS ON THURSDAY
BEFORE INCREASING AGAIN AS A SECOND WRAP ADVECTS ONSHORE ACROSS
THE SOUTHERN PANHANDLE. COULD SEE WIND ADVY GUSTS NORTH OF
FREDERICK SOUND WEDNESDAY NIGHT AND THURSDAY BUT WITH THE SURFACE
LOW REMAINING WEST OF 140W WILL WAIT FOR FUTURE MODEL RUNS TO
BETTER DEPICT THE LLJ BEFORE INCLUDING WIND ADVY GUSTS. WITH THIS
STRONG OF A SURFACE LOW DEEPENING IN THE GULF WILL ALSO SEE LARGE
WEST TO SOUTHWESTERLY SWELLS DEVELOP WITH SEAS TO NEAR 35 FEET ON
THURSDAY ACROSS THE EASTERN GULF. THE HEAVIEST RAINFALL AMOUNTS
THROUGH THURSDAY WILL REMAIN ALONG THE OUTER COAST AND SOUTHERN
PANHANDLE WHERE THE BEST UPPER LEVEL DYNAMICS REMAIN.

WHILE THE 949 MB SURFACE LOW WEAKENS AND FILLS FRIDAY AND EARLY
SATURDAY WILL CONTINUE TO SEE ONSHORE FLOW AND PERIODS OF RAIN
ACROSS THE PANHANDLE WITH LOCALLY BREEZY CONDITIONS. BY THE LATE
WEEKEND THE 12Z MODELS ARE DEVELOPING ANOTHER GALE FORCE LOW IN
THE NORTHEASTERN PACIFIC BUT THE EXACT TRACK OF THIS LOW COULD BE
TOWARD YAKUTAT OR INTO DIXON ENTRANCE AND THE ENSEMBLE SPREAD IS
QUITE LARGE. ATTM...WILL WAIT FOR BETTER MODEL CONSISTENCY BEFORE
MAKING ANY CHANGES.

FORECAST CONFIDENCE IS BELOW AVERAGE AFTER FRIDAY AS MODEL RUN TO
RUN CONSISTENCY IS VERY POOR. EXPECT TEMPERATURES TO BE ABOVE
NORMAL THROUGH THE WEEKEND WITH THE RAIN/SNOW LINE RETREATING INTO
CANADA WITH PRECIP AMOUNTS ABOVE NORMAL AS WELL.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...WIND ADVISORY FROM 3 PM WEDNESDAY TO 3 PM AKST THURSDAY FOR
     AKZ026-028.
         WIND ADVISORY FROM 6 AM WEDNESDAY TO 3 PM AKST THURSDAY FOR
     AKZ027.
         WIND ADVISORY FROM NOON WEDNESDAY TO 3 PM AKST THURSDAY FOR
     AKZ022.
         WIND ADVISORY FROM 9 AM WEDNESDAY TO 3 PM AKST THURSDAY FOR
     AKZ023.
MARINE...GALE WARNING FOR PKZ012-033-035-036-041>043-051-052.
         SMALL CRAFT ADVISORY FOR PKZ011-013-021-022-031-032-034.

&&

FRITSCH/PSS

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE JUNEAU AK
333 PM AKST TUE NOV 3 2009

AKZ017>029-041415-
CAPE FAIRWEATHER TO CAPE SUCKLING COASTAL AREA-
TAIYA INLET AND KLONDIKE HIGHWAY-HAINES BOROUGH AND LYNN CANAL-
GLACIER BAY-EASTERN CHICHAGOF ISLAND-
SALISBURY SOUND TO CAPE FAIRWEATHER COASTAL AREA-
CAPE DECISION TO SALISBURY SOUND COASTAL AREA-
EASTERN BARANOF ISLAND AND SOUTHERN ADMIRALTY ISLAND-
JUNEAU BOROUGH AND NORTHERN ADMIRALTY ISLAND-
INNER CHANNELS FROM KUPREANOF ISLAND TO ETOLIN ISLAND-
DIXON ENTRANCE TO CAPE DECISION COASTAL AREA-
SOUTHERN INNER CHANNELS-MISTY FJORDS-
INCLUDING THE CITIES OF...YAKUTAT...SKAGWAY...HAINES...GUSTAVUS...
HOONAH...ELFIN COVE...PELICAN...SITKA...PORT ALEXANDER...ANGOON...
JUNEAU...PETERSBURG...WRANGELL...KAKE...CRAIG...KLAWOCK...
KETCHIKAN...METLAKATLA...HYDER
333 PM AKST TUE NOV 3 2009

...STRONG STORM TO IMPACT SOUTHEAST ALASKA WEDNESDAY AND
THURSDAY...

A POWERFUL STORM CONTINUES TO DEVELOP IN THE NORTHERN PACIFIC AND
WILL MOVE INTO THE EASTERN AND CENTRAL GULF WEDNESDAY AND
THURSDAY. THE PANHANDLE CAN EXPECT GUSTY WINDS, HIGH SEAS, AND
ABOVE NORMAL TIDES.

THE TRACK OF THE LOW ALONG WITH A LONG WIND FETCH WILL PRODUCE
LARGE SWELLS AND SEA STATES GREATER THAN 25 FT IN THE GULF.

VERY HIGH ASTRONOMICAL TIDES ARE FORECAST FOR BOTH WEDNESDAY AND
THURSDAY FOR MANY LOCATIONS IN THE PANHANDLE. SURGE MODELS
CONTINUE TO INDICATE THAT A SURGE OF 1 TO 2 FEET IS POSSIBLE WITH
THIS STORM ON TOP OF THE ALREADY VERY HIGH TIDES. THE MOVEMENT OF
THE STORM TRACK HAS BEEN FURTHER SOUTH IN TODAYS MODEL RUNS AND
THEREFORE EXPECT THE HIGHEST SURGE TO REMAIN SOUTH OF SITKA AND
INTO DIXON ENTRANCE. NEAR YAKUTAT THE SURGE WILL REMAIN BELOW 1
FOOT. THE BEST CHANCE FOR A COASTAL FLOOD SITUATION WILL REMAIN
SOUTH OF BARANOF ISLAND ON THE 5TH AND 6TH OF NOVEMBER AT HIGH TIDE.

THE ADVISORY LEVEL WIND GUSTS ARE COVERED IN MORE DETAIL IN THE
CURRENT WIND ADVISORY STATEMENT.

PSS