Gale Warning 440, NWS Juneau, AK

961 
FZAK67 PAJK 291219
OFFAJK

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE JUNEAU AK
400 AM AKST SAT DEC 29 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.

PKZ398-300100-
400 AM AKST SAT DEC 29 2012 
.SYNOPSIS FOR THE EASTERN GULF OF ALASKA...
A 967 MB STORM FORCE LOW WILL ENTER THE SOUTHWEST GULF SATURDAY
MORNING AND DEEPEN TO 955 MB AS IT APPROACHES KODIAK ISLAND ON
SUNDAY. THE ASSOCIATED WEATHER FRONT WILL APPROACH THE OUTER
COAST LATE SUNDAY NIGHT.   

$$

PKZ310-300100-
GULF OF ALASKA NORTH OF 55 DEGREES NORTH AND EAST OF 144 DEGREES
WEST-
400 AM AKST SAT DEC 29 2012 

...GALE WARNING TODAY THROUGH TONIGHT...

.TODAY...SE WIND 30 KT INCREASING TO 35 KT IN THE AFTERNOON. SEAS
12 FT. RAIN IN THE AFTERNOON.
.TONIGHT...SE WIND 45 KT. SEAS 18 FT. RAIN.
.SUN...SE GALE TO 45 KT. SEAS 23 FT. 
.SUN NIGHT...S WIND 25 KT. SEAS 20 FT. SW SWELL. 
.MON...SE WIND 30 KT. SEAS 16 FT. 
.TUE...SE WIND 30 KT. SEAS 19 FT. 
.WED...SE WIND 20 KT. SEAS 16 FT. 

$$

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
330 PM AKST FRI DEC 28 2012

.SHORT RANGE...QUIETER DAY ACROSS THE PANHANDLE TODAY AS YESTERDAYS
FRONT IS WELL INTO CANADA AT THIS POINT. A POST FRONTAL SURFACE
TROUGH IS WHAT IS PRODUCING THE CURRENT BATCH OF SNOW AND RAIN.
SNOW FALL RATES ARE RATHER LIGHT WITH THIS TROUGH AS THERE IS NOT
MUCH MOISTURE ASSOCIATED WITH IT AT THE MOMENT. THERE ISN'T MUCH
WARM AIR ADVECTION EITHER AS TEMPERATURES HAVE WARMED UP SLOWLY
OVER NIGHT ACROSS THE AREA BUT SOME INNER CHANNEL AREAS
(PETERSBURG, WRANGELL, JUNEAU, GUSTAVUS, HAINES, AND SKAGWAY) ARE
STILL COLD ENOUGH FOR SNOW.

THE LACK OF MOISTURE AND WEAK WARM AIR ADVECTION WILL CONTINUE WITH
THE NEXT WEAKER TROUGH THAT IS CURRENTLY VISIBLE ON SATELLITE OVER
THE CENTRAL GULF. THIS ONE IS DRIVEN MORE BY UPPER LEVEL VORTICITY
RATHER THEN THE SURFACE LOW PRESSURE TROUGH. IT WILL BRING MORE
PRECIP TO THE AREA FOR LATE TONIGHT INTO TOMORROW BUT PRECIP
AMOUNTS WILL BE LESS THEN WHAT WE ARE GETTING FROM THE CURRENT
TROUGH OVER THE PANHANDLE. THE SLOW WARMING WILL ALSO CONTINUE
WITH THE AREAS AROUND JUNEAU, GUSTAVUS, AND POSSIBLY PETERSBURG
AND WRANGELL FINALLY GETTING WARM ENOUGH FOR A MIX WITH RAIN LATER
THIS AFTERNOON AND TONIGHT. A STRONGER WARM UP BEGINS ONCE THAT
VORTICITY MAX WITH ITS ASSOCIATED UPPER TROUGH MOVE OFF TO THE
EAST AND AN UPPER RIDGE MOVES IN FOR SAT. THIS WILL ALLOW A
SURFACE RIDGE TO FINALLY GET A GRIP AND BUILD NORTHWARD INTO THE
NORTHERN HALF OF THE PANHANDLE BRINGING STRONGER SOUTHERLY WINDS
WITH IT. BY SAT AFTERNOON MOST PLACES WILL BE WARM ENOUGH FOR RAIN
INSTEAD OF SNOW. THE EXCEPTION WILL BE THE HAINES AND KLONDIKE
HIGHWAY.

THINGS START GETTING FRISKY OUT IN THE GULF AS A WEAKENING FRONT,
FROM A LOW THAT IS CURRENTLY OVER THE EASTERN ALEUTIANS, STALLS
OVER THE CENTRAL GULF. THIS FEATURE WILL BRING SMALL CRAFT WINDS
TO THE COASTAL GULF ZONES AND GALES TO THE CENTRAL GULF AND
EXTREME NORTHERN GULF LATE TONIGHT. WINDS WILL THEN SLACK OFF A
BIT ONLY TO INCREASE YET AGAIN IN THE CENTRAL GULF AS ANOTHER
STRONGER FRONT COMES NORTHWARD SWALLOWING THE STALLED FRONT AS IT
COMES SAT AFTERNOON.

SHORT RANGE MODELS ARE IN DECENT AGREEMENT FOR THE TONIGHT AND SAT
MORNING PERIOD BUT THEN START DIVERGING ON HOW TO HANDLE THE NEXT
NORTHWARD MOVING LOW ON SAT AFTERNOON. MODELS WERE IN TWO CAMPS
THIS MORNING WITH THE ECMWF/NAM FAVORING A WEAKER, TWO CENTER LOW
WITH A FARTHER EAST TRACK WHILE THE GFS/UK/GEM/SREF WENT FOR A
STRONGER SINGLE LOW WITH A TRACK FARTHER WEST. FAVORED THE SECOND
CAMP ESPECIALLY WHEN THE LATER RUNS OF THE ECMWF AND THE NAM
SWITCHED SIDES. DECIDED ON A BLEND TO THE NAM THROUGH SAT MORNING
THEN SWITCHED TO GFS FOR SAT AFTERNOON AS THE INFLUENCE FROM THE
NEXT FRONT INCREASES. FORECAST CONFIDENCE IS ABOUT AVERAGE.
&&

.LONG TERM...
PATTERN HAS BECOME SOMEWHAT STABLE IN THAT A SOUTH COMPONENT OF THE
UPPER LEVEL WIND OVER THE PANHANDLE WILL PERSIST FOR A WEEK. THIS
IS DUE TO THE MEAN POSITION OF THE MAJOR UPPER LOW PERSISTING OVER
THE BERING SEA. NATURALLY THE DETAILS OF SYSTEMS IN THE SOUTHERLY
FLOW ALOFT ARE MESSY DUE TO THE UNCERTAINTY IN THE TIMING. OVERALL
THEME IS TO FORECAST RAIN AT LOWER LEVELS INSTEAD OF SNOW...WARMER
TEMPERATURES...AND SOME STRONG WIND AT TIMES PARTICULARLY ALONG THE
OUTER COAST AND OFFSHORE.

NOW FOR THOSE MESSY DETAILS: 1)CERTAIN OF A LONG FETCH TO BUILD BIG
SEAS IN THE EASTERN GULF FOR A WEEK. EXPECT A MONDO-BIG SW SWELL IN
THE 20S AND WOULDNT BE TOO SURPRISED TO SEE 30 FT. 2) PRECIP WATER
AMOUNTS WILL BE HIGH PARTICULARLY SUN THRU TUE. AGAIN CERTAIN OF A
LONG SOUTH FETCH AIMED AT CORDOVA SUN THROUGH MON NIGHT CALLED AN
ATMOSPHERIC RIVER. SOME WOULD CALL IT A PINEAPPLE EXPRESS. MODELS
SHOW A COUPLE OF INCHES OF WATER HEADED FOR PAYA. TIMING IFFY. 3)
COORDINATED WITH ANCHORAGE ON A BARRIER JET ALONG THE GULF COAST
ROUGHLY CAPE YAKATAGA EARLY SUN FOR STORM FORCE. 4) KEEP AN EYE ON
FREEZING LEVELS FOR A POSSIBLE SNOW DUMP NORTHERN HIGHWAYS. NOTHING
AT ALL CERTAIN YET. BEST GUESS WOULD BE WED NITE OR THU. 5)MELTING
WILL NOT IN ANY WAY BE EXTREME THOUGH ONE MAY SEE SOME BIG PUDDLES
FOR SNOW-FILLED DRAINS.

USED 28/12Z AK-GFS-40 FOR THE OPERATIONAL MODEL TODAY. LIKED HPC
GUIDANCE TODAY FOR THE PERSISTENT SOUTHERLY FLOW DAYS 4 THRU 8.
CONFIDENCE HIGH IN GENERAL PATTERN BUT AT BEST MODERATE IN THE
DETAILS PARTICULARLY TIMING. WARMER AND WETFOOT.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ052.
         SMALL CRAFT ADVISORY FOR PKZ041>043-051.
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ022-053.
&&

EAL/JC