Gale Warning 4, NWS Juneau, AK

448 
FZAK67 PAJK 051230
OFFAJK

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE JUNEAU AK
400 AM AKST WED JAN 5 2011 

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.

PKZ398-060100-
400 AM AKST WED JAN 5 2011 
.SYNOPSIS FOR THE EASTERN GULF OF ALASKA...
A DEVELOPING LOW W OF THE CHARLOTTES WILL MOVE N TO NEAR CAPE
DECISION BY EARLY THIS AFTERNOON...THEN CONTINUE INLAND THROUGH
CENTRAL SE ALASKA AND WEAKEN THROUGH THIS EVENING. 

$$

PKZ310-060100-
GULF OF ALASKA NORTH OF 55 DEGREES NORTH AND EAST OF 144 DEGREES
WEST-
400 AM AKST WED JAN 5 2011 

.TODAY...S WIND 20 KT. SEAS 24 FT. W SWELL. 
.TONIGHT...SW WIND 25 KT. SEAS 22 FT SUBSIDING TO 18 FT
OVERNIGHT. W SWELL. RAIN.
.THU...SW WIND 20 KT. SEAS 15 FT. W SWELL. 
.THU NIGHT...N WIND 20 KT. SEAS 11 FT. W SWELL. 
.FRI...NW WIND 25 KT. SEAS 8 FT. W SWELL. 
.SAT...NW WIND 25 KT. SEAS 7 FT. 
.SUN...N WIND 20 KT. SEAS 8 FT. 

$$

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
137 PM AKST TUE JAN 4 2011

.SHORT TERM...A RATHER COMPLICATED SHORT TERM FORECAST TODAY AS
THE 12Z MODEL RUNS ARE HAVING A VERY DIFFICULT TIME COMING INTO
AGREEMENT ON A DEVELOPING GALE FORCE LOW MOVING OUT OF THE
NORTHEASTERN PACIFIC TO JUST WEST OF BARANOF ISLAND BY TOMORROW
AFTERNOON. THE 00Z/12Z ECMWF ALONG WITH THE GEM ARE THE ONLY
MODELS TO DEVELOP THIS GALE FORCE LOW AND HAVE BEEN VERY
CONSISTENT WITH THEIR SOLUTIONS OVER THE PAST DAY WHILE THE
NAM/GFS SOLUTIONS KEEP THE MID LEVEL TROUGH AS AN OPEN WAVE
MOVING SOUTH OF THE PANHANDLE. GIVEN THE AMOUNT OF CAA MOVING
INTO THE DEVELOPING BAROCLINIC WAVE SEEN ON THE EARLY AFTERNOON
SATELLITE IN THE NORTHERN PACIFIC AND THAT THE ECMWF INITIALIZED
THE MID LEVEL ENVIRONMENT THE BEST...PREFERRED THE 12Z ECMWF FOR
THE SHORT TERM PERIOD TODAY WHICH GIVES RISE TO A COMPLICATED
WIND PATTERN AND THE RAIN/SNOW LINE MOVING SOUTHWARD TO THE ICY
STRAIT CORRIDOR BY TOMORROW. FORECAST CONFIDENCE IS BELOW AVERAGE
THROUGH THE SHORT TERM PERIOD GIVEN THE POOR MODEL CONSENSUS
TODAY.

 FOR TONIGHT SOUTHWESTERLY MID LEVEL FLOW WILL CONTINUE ACROSS
THE PANHANDLE WITH CAA AT MID LEVELS AND THIS WILL ALLOW FOR THE
PRECIP TO BECOME MORE CONVECTIVE IN NATURE. A MID LEVEL RIDGE
WILL QUICKLY ADVECT ACROSS THE SOUTHERN PANHANDLE THIS EVENING
AND THAT WILL ALSO ACT TO LIMIT THE SHOWER ACTIVITY. WINDS WILL
BE THE MAIN CONCERN FOR TONIGHT AS THE SURFACE PRESSURE GRADIENT
WILL REMAIN SOUTHERLY WITH WIND ADVY GUSTS NEAR SKAGWAY INTO THE
EVENING HOURS AND GALE FORCE WINDS IN LYNN CANAL. ELSEWHERE WINDS
WILL BE LOCALLY BREEZY DURING THE EVENING HOURS BEFORE BECOMING
NORTHERLY EARLY WEDNESDAY MORNING AS A SURFACE LOW DEVELOPS IN
THE NORTHEASTERN PACIFIC AND MOVES INTO THE SOUTHEASTERN GULF.
WITH THE MID LEVEL CAA WILL SEE 850 MB TEMPERATURES DROP TO -5 C
NORTH OF FREDERICK SOUND AND THIS WILL ALLOW SNOW TO MIX TO THE
SURFACE IN THE STRONGER SHOWERS...HOWEVER LIGHTER PRECIP AMOUNTS
AND WARMER GROUND TEMPERATURES WILL LIMIT ANY SNOW ACCUMULATIONS
TONIGHT.

 FOR WEDNESDAY WILL SEE A GALE FORCE LOW CONTINUE TO DEVELOP AS
IT MOVES TO JUST WEST OF SITKA BY THE EARLY AFTERNOON. THIS WILL
LEAD TO A STRONG AND RAPIDLY CHANGING SURFACE PRESSURE GRADIENT
WITH WINDS BECOMING NORTHEASTERLY DURING THE EARLY MORNING HOURS
ONLY TO QUICKLY BECOME SOUTHERLY DURING THE AFTERNOON HOURS AS
THE SURFACE LOW AND ASSOCIATED FRONTAL BOUNDARY MOVE THROUGH THE
SOUTHERN PANHANDLE. AM CONCERNED THAT PRINCE OF WALES ISLAND AND
CLARENCE STRAIT WILL AGAIN SEE WIND ADVY GUSTS TOMORROW GIVEN THE
850 MB LLJ WINDS NEAR 50 KNOTS AND WILL SEE GALE FORCE WINDS IN
ASSOCIATED MARINE AREAS. PRECIP FROM THE ASSOCIATED FRONTAL BAND
WILL MOVE NORTHWARD ACROSS THE PANHANDLE TOMORROW AND WILL SEE A
DEFORMATION BAND DEVELOP ALONG THE ICY STRAIT CORRIDOR AND THIS
COULD LEAD TO SOME MODERATE TO HEAVY PRECIP RATES. GIVEN THE
COOLING MID LEVELS AND NORTHERLY SURFACE FLOW DO EXPECT SNOW
ACCUMULATION TOMORROW ACROSS THE CENTRAL AND NORTHERN PANHANDLE
WITH THE HIGHEST AMOUNTS NEAR HOONAH AS THE UPSLOPE SURFACE
EASTERLIES WILL INCREASE PRECIP AMOUNTS. ATTM BELIEVE SNOW TOTALS
WILL REMAIN BELOW ADVY GIVEN THE 850 MB TEMPS NEAR -5 C...HOWEVER
IF THE PRECIP RATES INCREASE ENOUGH WITH ISENTROPIC GLIDE ACROSS
THE DEFORMATION ZONE COULD SEE HIGHER SNOWFALL AMOUNTS. WITH THE
NORTHERLY SURFACE PRESSURE GRADIENT INCREASING THROUGH WEDNESDAY
NEAR HAINES AND SKAGWAY...PRECIP AMOUNTS WILL BE MORE LIMITED BUT
VISIBILITIES WILL CONTINUE TO BE REDUCED AT TIMES DUE TO BREEZY
CONDITIONS AND LIGHT SNOW. THIS GALE FORCE LOW TOMORROW BEARS
WATCHING AS ITS EXACT TRACK WILL DETERMINE THE LOCATION OF THE
HIGHEST SNOWFALL AMOUNTS, ACROSS THE CENTRAL AND NORTHERN
PANHANDLE, AND THE STRONGEST WINDS, ACROSS THE SOUTHERN PANHANDLE
AND DIXON ENTRANCE.

&&

 .LONG TERM...LONG RANGE MODELS ARE STILL HAVING SOME
DISAGREEMENTS THROUGH THE PERIOD. THE MID RANGE FORECAST STARTS
OUT WITH THE REMAINS OF THE CURRENT SYSTEM MOVING THROUGH THE
PANHANDLE. EC AND UK AND EVEN THE GEM ARE STILL RATHER PERSISTENT
ON A TRIPLE POINT LOW/TROUGH MOVING INTO THE CENTRAL OUTER COAST
WED NIGHT WHILE THE GFS AND NAM WHICH JUST STARTED SHOWING THE
FEATURE HAVE IT WEAKER AND FARTHER SE. GIVEN THE RUN TO RUN
CONSISTENCY OF THE EC AND UK WITH THIS FEATURE AND THE GOOD
INITIALIZATION OF THE 12Z EC DECIDED TO GO WITH THE 12Z EC FOR
UPDATES IN THE MID RANGE. THE POSITION OF THE TRIPLE POINT
FEATURE WILL MAKE THE PTYPE OVER THE NORTHERN AREA SOMEWHAT
TRICKY. NORTHERLY FLOW AHEAD OF THE FEATURE WILL CAUSE SOME
MIXING WITH SNOW AS FAR SOUTH AS HOONAH AND JUNEAU, BUT AS THE
TROUGH GOES BY THE WINDS WILL SWITCH AROUND TO THE SOUTH AND
BRING WARMER AIR INTO THE AREA FOR WED AFTERNOON. FINALLY A
CHANGE TO ALL SNOW WILL OCCUR BY THURSDAY AS COLDER AIR THAT HAS
BEEN TRAVELING AROUND THE MAIN PARENT LOW INFILTRATES THE
PANHANDLE FROM THE SW WITH 850 MB TEMPS DROPPING INTO THE . WITH
THE SHOWERS STILL COMING INTO THE PANHANDLE THURS INTO FRIDAY
SOME AREAS MAY RECEIVE A DECENT AMOUNT OF SNOW BEFORE THE OUTFLOW
FROM THE CANADIAN INTERIOR SHUTS IT DOWN.

 BY THE WEEKEND, UPPER RIDGE WILL BE BUILDING OVER WESTERN ALASKA
CAUSING A COLD SURFACE HIGH TO BEGIN BUILDING IN THE INTERIOR OF
CANADA. OUTFLOW WINDS WILL BE STARTING TO BLOW OUT OF INTERIOR
PASSES AND DOWN LYNN CANAL. LYNN CANAL WILL BE BLOWING AT LEAST
SCA LEVEL FROM THE WEEKEND ONWARD. TEMPERATURES WILL ALSO BE COLD
AS WELL. HIGH TEMPS WILL STRUGGLE TO GET OUT OF THE 20S IN THE
NORTHERN PANHANDLE BY EARLY NEXT WEEK. MODEL AGREEMENT IS STILL A
BIT OFF. EC HAS NOW ADOPTED THE MORE WESTWARD POSITION OF THE
UPPER RIDGE THAT THE GFS WAS DISPLAYING YESTERDAY. IT HAS ALSO
ADOPTED THE SCENARIO THAT THE RIDGE WILL TURN INTO A CUT OFF HIGH
NEAR NW ALASKA BY MID WEEK NEXT WEEK. DECIDED TO GO WITH THE HPC
SOLUTION OF THE POSITION MORE TO THE WEST BUT STILL FAVORING THE
EC AND THE ENSEMBLES ON MOST COUNTS FOR THE EXTEND PERIOD.
FORECAST CONFIDENCE IS FAIR FOR THE PERIOD.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...WIND ADVISORY UNTIL 9 PM AKST THIS EVENING FOR AKZ018.
MARINE...GALE WARNING FOR PKZ012-036-041-042.
         SMALL CRAFT ADVISORY FOR PKZ013-021-022-031>035-043-051>053.

&&

PSS/EAL