Gale Warning 434, NWS Juneau, AK

441 
FZAK67 PAJK 181234
OFFAJK

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE JUNEAU AK
400 AM AKST TUE DEC 18 2012 

OFFSHORE WATERS FORECAST FOR GULF OF ALASKA EAST OF 144W

WIND FORECASTS REFLECT THE PREDOMINANT SPEED AND DIRECTION
EXPECTED. SEA FORECASTS REPRESENT THE AVERAGE OF THE HIGHEST
ONE-THIRD OF THE COMBINED WINDWAVE AND SWELL HEIGHT.

PKZ398-190100-
400 AM AKST TUE DEC 18 2012 
.SYNOPSIS FOR THE EASTERN GULF OF ALASKA...
A GALE FORCE LOW WILL MOVE INTO THE CENTRAL GULF TUE WITH THE
ASSOCIATED FRONT REACHING THE SOUTHERN PANHANDLE TUE EVENING.
HIGH PRESSURE IN THE YUKON TERRITORY WILL CONTINUE TO SEND
ARCTIC AIR INTO THE PANHANDLE THROUGH WED. 

$$

PKZ310-190100-
GULF OF ALASKA NORTH OF 55 DEGREES NORTH AND EAST OF 144 DEGREES
WEST-
400 AM AKST TUE DEC 18 2012 

...GALE WARNING THROUGH TONIGHT...

.TODAY...SE WIND 35 KT INCREASING TO 40 KT IN THE AFTERNOON. SEAS 9
FT BUILDING TO 15 KT. RAIN AND SNOW. 
.TONIGHT...SE WIND 40 KT. SEAS 16 FT BUILDING TO 22 FT. RAIN.
.WED...E GALE TO 40 KT DIMINISHING IN THE AFTERNOON. SEAS 20 FT.
RAIN.
.WED NIGHT...NE WIND 30 KT. SEAS 17 FT SUBSIDING TO 13 FT. RAIN.
.THU...NE WIND 25 KT. SEAS 10 FT. W SWELL. 
.FRI...NE WIND 20 KT. SEAS 6 FT. 
.SAT...WIND VARIABLE LESS THAN 15 KT. SEAS 6 FT. 

$$

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
400 PM AKST MON DEC 17 2012

.SHORT TERM....SHORT TERM...988 MB LOW ABOUT 120 SW OF SITKA WILL BE MOVING SE
ALONG HAIDA GWAII ABOUT 06Z-09Z. THIS TRACK IS PARTIALLY DUE TO
INTERACTION WITH THE MAJOR SYSTEM THAT MADE LANDFALL NEAR SEATTLE
TODAY.

THE ARCTIC OUTBREAK ALREADY OVER THE NORTHERN TWO THIRDS OF THE
PANHANDLE WILL CONTINUE TO SPREAD S. THE NORTHERLY PRESSURE
GRADIENT ALONG THE PANHANDLE IS SUPPORTED BY A COMBINATION OF
THE ARCTIC HIGH IN YUKON TERRITORY AND THE LOW TO THE SOUTH.

CONFIDENCE IS AVERAGE. PLEASE NOTE THE ARCTIC OUTBREAK IS ALSO
PROVIDING FREEZING SPRAY IN THE NORTHERN INNER CHANNELS AS WELL
AS STEPHENS PASSAGE AND OUT OF INTERIOR PASSES.

THE TRACK AND DEPTH OF THE LOW AS WELL AS THE ARCTIC OUTFLOW
SOURCE IN YUKON TERRITORY HAVE BEEN THE PRIMARY ISSUES. FOR
THE LOW TO THE SOUTH, THE CONVECTION IS STILL IMPORTANT TO
SOUTHERN SOUTHEAST ALASKA, ALBEIT THE LOW ITSELF IS PROVIDING
THE NORTHERLY FLOW ENHANCEMENT FARTHER S.

GOES VISIBLE IMAGES SHOW AS AND AC DECKS OVER NW BRITISH COLUMBIA
AND THE NORTHERN PANHANDLE. WEB CAMERA POINTED TO THE NE OF
SKAGWAY SHOWS THE AC FROM UNDERNEATH. THE ECMWF, GFS, AND NAM ALL
SHOW THE 700 LAYER RH DRYING OUT FROM THE NW BY ABOUT 06Z.

THE GOES IR SHOWS THE BANDS OF CONVECTION ASSOCIATED WITH THE LOW.
EMBEDDED CYCLONIC FEATURES SHOW UP WELL, ALBEIT THESE ARE WITHIN
AN AIR MASS AND NONE SHOULD BE CYCLOGENETIC.

.LONG TERM...MODELS STILL STRUGGLING WITH SOME OF THE DETAILS LATE
WEEK INTO THE WEEKEND...BUT THE PATTERN SUGGESTS IT WILL REMAIN
COLD THROUGH THE PERIOD ESPECIALLY OVER THE NRN AND CENTRAL AREAS.
LOOKS LIKE THE MODELS ARE BEGINNING TO COME INTO BETTER AGREEMENT
ON HOW THE UPPER RIDGE OVER THE WRN PART OF THE STATE WILL
EVOLVE...WITH A GOOD CONSENSUS ON THE RIDGE PINCHING OFF TO AN
UPPER HIGH OVER THE NW OR N-CENTRAL PART OF AK BY THE FRI/SAT TIME
FRAME. THIS TENDS TO MAINTAIN VERY COLD AIR OVER THIS AREA UNTIL
AN UPPER LOW OR TROF CAN DEVELOP TO THE S OF THE UPPER HIGH...OVER
THE GULF OR SRN PART OF AK...WHICH MODELS HINT AT LATER IN THE
WEEKEND AND EARLY NEXT WEEK. CURRENT FORECAST AS FAR AS WINDS AND
PRESSURES STILL LOOKED GOOD SO DECIDED TO LIMIT CHANGES TO OTHER
ELEMENTS...MAINLY TEMPS AND POPS.

FOR TUE NIGHT INTO WED NIGHT...A LOW OVER THE S-CENTRAL GULF WILL
DRIFT SE AS LARGE SCALE FLOW AMPLIFIES...DIGGING UPPER TROF OVER
THE GULF AND FAR ERN PAC. LOOKS LIKE PRECIP FROM THE LOW AND THE
ASSOCIATED OCCLUDED FRONT WILL BE GENERALLY LIMITED TO THE SRN
AREA...ALTHOUGH A FEW FLURRIES OR A PERIOD OF LIGHT SNOW IS
POSSIBLE IN THE CENTRAL AREA WED INTO WED NIGHT ESPECIALLY WHERE
ELY FLOW IS UPSLOPE. DID NOSE SOME HIGHER POPS NWD INTO THE PAOH
AREA FOR THIS REASON...BUT KEPT THEM AT CHANCE LEVELS. THE E SIDE
OF BARANOF ISLAND MAY END UP GETTING THE MOST PRECIP OUT OF THIS
SYSTEM AS THE FLOW WILL REMAIN UPSLOPE THERE INTO WED...AND WITH
JUST COLD ENOUGH AIR IN AT THE LOWER LEVELS...COULD SEE A DECENT
SNOW EVENT. WILL NOT ISSUE ANY STATEMENTS YET AS THERE REMAIN
ENOUGH DIFFERENCES BETWEEN THE MODELS ON HOW FAST THE FRONT LIFTS
NWD AND WEAKENS...THUS HOW LONG THE STRONGER ELY FLOW PERSISTS IN
THE PRE-FRONTAL ENVIRONMENT...AND HOW MUCH PRECIP FALLS. ANOTHER
ISSUE DURING THIS TIME IS POTENTIAL FOR MOUNTAIN WAVE DEVELOPMENT
IN THE JUNEAU AREA. BOTH GFS AND NAM SHOW AT LEAST MARGINAL
CONDITIONS WITH A FEW PERIODS OF FAVORABLE...WHICH COULD LEAD TO
LOW END WARNING LEVEL WINDS. THE CRITICAL LEVEL DOES JUMP UP
FAIRLY HIGH HOWEVER SO NOT ENOUGH CONFIDENCE TO ISSUE ANYTHING
ATTM.

FOR THU INTO THE WEEKEND...LOW PULLS AWAY FROM THE AREA ALTHOUGH
FRONT ALOFT DRIFTS NWD OVER THE NRN AND CENTRAL AREA INTO FRI
BEFORE IT SLOWLY DISSIPATES. THINK THIS WILL MAINLY MAINTAIN SOME
MID-LEVEL CLOUDS OVER THE AREA ALTHOUGH A FEW FLURRIES CANNOT BE
RULED OUT. COLDER AIR WILL MOVE BACK IN THU-SAT AND HAVE LOWERED
TEMPS IN RESPONSE. MOS GUIDANCE IS COLDER THAN THE FORECAST WILL
HAVE AT THIS POINT BUT WANTED TO JUST TREND TEMPS DOWNWARD AND NOT
JUMP ALL THE WAY TO THE MOS NUMBERS YET. TEMPS WILL BE WELL BELOW
AVERAGE DURING THIS TIME IN ANY CASE.

EARLY NEXT WEEK...WITH UPPER HIGH ESTABLISHED OVER THE FAR NRN
PART OF THE STATE...MAY HAVE TO WATCH FOR ENERGY MOVING AROUND
THE HIGH FROM THE N-NE AND DIGGING INTO THE GULF OR SRN PART OF
AK. MODELS HINT AT THIS BUT DIFFER GREATLY ON TIMING AND POSITION
OF THE UPPER LOW THAT DEVELOPS. WILL ALSO HAVE TO WATCH FOR
INTERACTIONS WITH SRN STREAM SYSTEMS AS WELL THAT COULD BRING
PRECIP INTO THE AREA. FORECAST CONFIDENCE IS LOW DURING THIS TIME
EXCEPT THAT IT WILL LIKELY REMAIN COLDER THAN AVERAGE.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...STRONG WIND UNTIL MIDNIGHT AKST TONIGHT FOR AKZ018-019.
         WIND CHILL ADVISORY UNTIL 9 PM AKST THIS EVENING FOR AKZ018.
         STRONG WIND UNTIL 6 PM AKST THIS EVENING FOR AKZ017.
         WINTER WEATHER ADVISORY UNTIL 6 PM AKST THIS EVENING FOR AKZ028.
MARINE...HEAVY FREEZING SPRAY WARNING FOR PKZ011.
         HEAVY FREEZING SPRAY WARNING FOR PKZ012.
         STORM WARNING FOR PKZ012.
         GALE WARNING FOR PKZ011-013-022-041>043-051-052.
         SMALL CRAFT ADVISORY FOR PKZ021-031>036-053.

&&

JBT/RWT