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000
FXAK67 PAJK 162145
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
145 PM AKDT WED APR 16 2014

.SHORT TERM...EARLY AFTERNOON SATELLITE IMAGERIES REVEAL A
DEVELOPING GALE FORCE LOW CONTINUING ITS NORTHEASTWARD PROGRESS
TOWARDS PRINCE OF WALES ISLAND. BY THURSDAY MORNING, THE LOW WILL
BE AT ITS PEAK INTENSITY, AND IT WILL MOVE POLEWARD PARALLEL TO
THE OUTER COAST AND GRADUALLY WEAKEN THROUGH THURSDAY AFTERNOON.

 WITH A FEW BREAKS IN THE CLOUD COVER, TEMPERATURES GENERALLY
ROSE TO THE UPPER 40S TO THE LOW 50S THIS AFTERNOON ACROSS THE
PANHANDLE. LOCAL SEA BREEZES DEVELOPED IN SKAGWAY, HAINES, AND
JUNEAU AREA. THESE SEA BREEZES WILL DIMINISH DURING THE EVENING
HOURS AS THE LAND COOLS OFF.

 WITH TIGHTENING PRESSURE GRADIENT, STRONG WINDS WILL DEVELOP IN
THE SOUTHERN PANHANDLE THIS EVENING. GUSTS TO 40 MPH ARE
EXPECTED. FOR BARANOF ISLAND, WIND GUSTS OF 30 TO 35 MPH
OVERNIGHT. EXPECT NORTHERLY WINDS OF 10 TO 15 MPH ACROSS THE
NORTHERN PANHANDLE TONIGHT. WITH A TIGHTER NORTHERLY PRESSURE
GRADIENT, DOWNTOWN JUNEAU AND DOUGLAS WILL SEE HIGHER
NORTHEASTERLY GUSTS COMING DOWN FROM SALISBURY RIDGE. AS THE LOW
PRESSURE SYSTEM WEAKENS ON THURSDAY, WINDS SHOULD DIMINISH ACROSS
THE PANHANDLE.

 CATEGORICAL PRECIPITATION WILL SPREAD INTO SOUTHERN PANHANDLE
TONIGHT. HOWEVER, PRECIPITATION WILL HAVE A TOUGH TIME SPREADING
NORTHWARD DUE TO THE PRESENCE OF DRIER OFFSHORE FLOW ACROSS THE
NORTHERN PANHANDLE. BY THURSDAY AFTERNOON, MEASURABLE
PRECIPITATION SHOULD SPREAD INTO THE REST OF THE PANHANDLE.
YAKUTAT AREA WILL REMAIN MOSTLY DRY, AS THEY ARE ON THE BACK SIDE
OF THE LOW PRESSURE SYSTEM THROUGH THURSDAY AFTERNOON.

 FORECAST CONFIDENCE IS ABOVE AVERAGE. NUMERICAL WEATHER MODELS
HAVE CONSENSUS ON THE TRACK OF THIS LOW PRESSURE SYSTEM. ECMWF
AND NAM ARE THE MODELS OF CHOICE. THE GFS SOLUTION PUTS THE
CENTER OF THE LOW A LITTLE BIT TOO FAR WEST. ALL MODELS AGREE
THAT PRECIPITATION SHOULD SPREAD ACROSS THE PANHANDLE BY THURSDAY
AFTERNOON.

&&

.LONG TERM...MODELS ARE IN GENERAL AGREEMENT THROUGH THE WEEKEND
WITH A WEAK UPPER LEVEL SHORTWAVE TROUGH ACROSS THE PANHANDLE
DRIFTS NORTHWARD ON FRIDAY AND AN UPPER LEVEL RIDGE BUILDS OVER
THE EASTERN GULF AND SOUTHEAST ALASKA FROM THE SOUTH. THE
ASSOCIATED SURFACE LOW IN THE NORTHEASTERN GULF ON THURSDAY NIGHT
WILL DISSIPATE AS A SURFACE RIDGE OF HIGH PRESSURE CONTINUES
BUILDS FROM THE SOUTH. THE UPPER RIDGE WILL DRIFT NORTHEASTWARD AS
AN UPPER LEVEL CUT-OFF LOW MOVES INTO SOUTHEASTERN GULF BY EARLY
SATURDAY MORNING. THE UPPER LOW WILL REMAIN OVER THE AREA THROUGH
THE WEEKEND. THE ASSOCIATED SURFACE LOW WILL MOVE INTO THE
SOUTHERN GULF BY FRIDAY NIGHT THEN BEGIN DOMINATING THE ENTIRE
GULF OF ALASKA THROUGH THE WEEKEND. REFRESHED THE INHERITED
FORECAST PACKAGE WITH THE ECMWF AND NAM THROUGH EARLY SUNDAY
MORNING AS THEIR GOOD CONSISTENCY AND CONSENSUS.

 THE UPPER LOW AND ASSOCIATED SURFACE FEATURE OVER THE ALASKA
GULF WILL BEGIN WEAKENING AND DRIFTING SOUTHEASTWARD...FOLLOWED BY
A RIDGE BUILDING OVER THE GULF THROUGH THE MID WEEK. MODEL
DIFFERENCES BECOME SIGNIFICANTLY LARGER AS THEY HANDLE THE RIDGE
FEATURE ACROSS THE GULF AND THE DEVELOPING LOW OVER THE FAR
WESTERN ALASKA PENINSULA. BLENDED THE REMAINING LONG TERM PERIODS
WITH THE WPC SOLUTIONS OF THE ECMWF ENSEMBLE APPROACH. SEVERAL
LOWS WILL DRIFT ACROSS THE GULF AND MOVE INTO THE EASTERN GULF.

 AS THE SURFACE LOW IN THE NORTHEASTERN GULF DISSIPATES...WINDS
WILL CONTINUE TO DECREASE ACROSS THE PANHANDLE THURSDAY NIGHT INTO
FRIDAY. POPS WILL DIMINISH AS WELL. WITH THE RIDGE BUILDING FROM
THE SOUTH...SOUTHERLY WINDS WILL BEGIN INCREASING THROUGH LATE
FRIDAY. BY EARLY SATURDAY MORNING...A SURFACE LOW MOVES INTO THE
SOUTHERN GULF AND PRODUCE GALE FORCE WINDS ACROSS THE SOUTHERN
OUTER WATERS AND THE PANHANDLE THROUGH THE WEEKEND. VERY ROUGH
SEAS UP TO 20 FEET ARE ALSO EXPECTED OVER THE SOUTHERN OUTER
WATERS. NORTHERLY WINDS WILL GRADUALLY INCREASE OVER THE
PANHANDLE. WITH INCREASING UNCERTAINTY...EXPECT A BRIEF RIDGE
BUILDS ACROSS THE GULF BEFORE ANOTHER DEVELOPING LOW OVER THE FAR
WESTERN ALEUTIANS DRIFTS EASTWARD AND PUSH SEVERAL WEAKER LOWS
INTO THE EASTERN GULF THROUGH THE MID WEEK.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...STRONG WIND FROM 7 PM AKDT THIS EVENING THROUGH THURSDAY MORNING
     FOR AKZ027.
         STRONG WIND FROM 7 PM AKDT THIS EVENING THROUGH THURSDAY MORNING
     FOR AKZ028.
MARINE...GALE WARNING FOR PKZ036-041>043.
         SMALL CRAFT ADVISORY FOR PKZ022-033-035-051-052.

&&

$$

RCL/AHN






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