Gale Warning 166, NWS Juneau, AK

239 
FZAK67 PAJK 011240
OFFAJK

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE JUNEAU AK
400 AM AKST THU MAR 1 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.

PKZ398-020100-
400 AM AKST THU MAR 1 2012 
.SYNOPSIS FOR THE EASTERN GULF OF ALASKA...
A WEATHER FRONT WILL MOVE INTO THE EASTERN GULF BY THURSDAY
AFTERNOON AND THEN OVER THE PANHANDLE THURSDAY NIGHT. 

$$

PKZ310-020100-
GULF OF ALASKA NORTH OF 55 DEGREES NORTH AND EAST OF 144 DEGREES
WEST-
400 AM AKST THU MAR 1 2012 

...GALE WARNING TODAY THROUGH TONIGHT...

.TODAY...S WIND 20 KT IN THE MORNING...INCREASING TO 40 KT. SEAS 10
FT. RAIN.
.TONIGHT...SW WIND 35 KT. SEAS 13 FT. 
.FRI...SW WIND 30 KT. SEAS 19 FT. 
.FRI NIGHT...SW WIND 25 KT. SEAS 20 FT. W SWELL. 
.SAT...SW WIND 20 KT. SEAS 15 FT. W SWELL. 
.SUN...W WIND 15 KT. SEAS 10 FT. 
.MON...W WIND 25 KT. SEAS 8 FT. 

$$

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
340 PM AKST WED FEB 29 2012

.SHORT TERM...BROAD AREA OF LOW PRESSURE OVER THE EASTERN GULF
AND PANHANDLE WITH HIGH PRESSURE RIDGE MOVING OVER THE CENTRAL AK
GULF. SATELLITE IMAGERY THIS AFTERNOON SHOWING MOSTLY SUNNY SKIES
OVER THE AK PANHANDLE WITH A FEW LINGERING SHOWERS OVER THE
NORTHWEST COAST. CLOUDS WILL INCREASE TONIGHT WITH APPROACHING
FRONT. WINDS HAVE BEEN GENERALLY LIGHT EXCEPT FOR THE NORTHERN
INNER CHANNELS WHERE NORTH-SOUTH PRESSURE GRADIENT PRODUCING
NORTHERLY SMALL CRAFT WINDS IN N LYNN CANAL AND BREEZY CONDITIONS
IN HAINES AND SKAGWAY IN THE MORNING. THESE WINDS HAVE DIMINISHED
THROUGH THE DAY AS THE GRADIENT WEAKENS. MAY SEE WINDS PICK UP
AGAIN TONIGHT TO SMALL CRAFT OVER N LYNN CANAL BUT THE GRADIENT
ORIENTATION MAY NOT BE AS CONDUCIVE. FOR THIS EVENING COASTAL
AREAS MAY SEE SOME SHOWER ACTIVITY AS MID LEVEL VORT MAX MOVES
OVER THE COAST. SHOWERS WILL BE MAINLY SNOW WITH DECREASING
TEMPERATURES BUT NOT EXPECTING ANY SIGNIFICANT ACCUMULATION AS
SHOWERS WILL BE SCATTERED TO ISOLATED. BIG CHANGE OCCURS THURSDAY
AFTERNOON INTO THURSDAY EVENING AS WEATHER FRONT ASSOCIATED WITH
LOW PRESSURE SYSTEM OVER KODIAK MOVES ACROSS THE EASTERN GULF
REACHING THE PANHANDLE COAST THURSDAY EVENING. SOME TIMING ISSUES
WITH RESPECT TO THE FRONT AS ECMWF MOVES IN THE FRONT THE
FASTEST, NAM THE SLOWEST AND GFS AS A MIDDLE GROUND. AS MODEL
DIFFERENCES WERE MINOR FOR TONIGHT USED THE 12Z GFS FOR THE
TIMING OF THE FRONT WITH SOME BLEND OF THE SREF FOR POP TO COVER
SPEED VARIABILITY. PRECIP THAT DOES REACH THE COAST IN THE
AFTERNOON SHOULD BE MAINLY RAIN AS AFTERNOON TEMPERATURES WARM TO
THE MID TO UPPER 30S. SIGNIFICANT PRECIP SHOULD NOT START UNTIL
TOMORROW EVENING. WINDS ALONG THE COASTAL WATERS WILL QUICKLY
PICKUP TO GALE FORCE TOMORROW WITH SMALL CRAFT WINDS ALONG THE
COASTAL CHANNELS. WINDS ALONG THE COASTAL ZONES WILL ALSO
INCREASE TO 25 MPH IN THE AFTERNOON WITH THE APPROACHING FRONT.

 CHANGES TO THE GRIDS WERE MINOR WITH RESPECT TO PRESSURE AND
WINDS A MODEL DIFFERENCES WERE MINOR. OVERNIGHT TEMPERATURES WERE
LOWERED USING SREF BC HOWEVER INCREASING CLOUDS MAY KEEP TEMPS A
BIT WARMER. FORECAST CONFIDENCE IS ABOVE AVERAGE BUT STILL
QUESTIONS ON THE TIMING OF THE FRONT FOR THURSDAY AFTERNOON.

 &&

 .LONG TERM...MEDIUM RANGE MODELS ARE IN DECENT AGREEMENT TODAY.
SOME SMALL DIFFERENCES STILL EXIST BETWEEN THEM FOR THE FRONT
COMING INTO THE PANHANDLE FOR THURS NIGHT MAINLY IN THE TIMING
AREA. GFS TURNED OUT TO BE A GOOD MIDDLE GROUND WITH THE EC A BIT
FAST AND THE NAM JUST A BIT SLOW. ALSO SOME DIFFERENCES IN HOW
COLD THE MODELS WERE GOING DURING FRONTAL PASSAGE. NAM WAS THE
COLDEST KEEPING MOST PLACES IN THE NORTHERN HALF OF THE AREA SNOW
THURS NIGHT. GFS AND EC ARE A BIT WARMER AND FEATURED SNOW MIXING
WITH RAIN IN MOST PLACES EXCEPT HAINES AND SKAGWAY THURS NIGHT.
THE LATTER TWO ALSO DISPLAYED A SLIGHT WARMING TREND OVER THE
PAST DAY OR TWO FOR THURS NIGHT.

 IN LIGHT OF THIS THE FRONTAL PASSAGE ON THURS NIGHT WILL BE A
BIT TRICKY FORECASTING SNOWFALL AMOUNTS. OVERNIGHT TEMPS IN MOST
PLACES WILL BE STEADY TO SLIGHTLY FALLING AS THE USUAL OVERNIGHT
COOLING WILL BE OFFSET BY THE WARM ADVECTION OF THE FRONT.
CURRENT THINKING IS THAT THE WARM ADVECTION WILL BE ENOUGH TO AT
LEAST HAVE A MIX OF RAIN AND SNOW FOR THE ICE STRAIT CORRIDOR
THURS NIGHT AS WELL AS A MIX FOR YAKUTAT. SNOW WILL MOSTLY BE
NORTH OF THAT AREA AND RAIN WILL FALL SOUTH OF THAT AREA. SNOW
AMOUNTS ARE AROUND ADVISORY FOR YAKUTAT AND HAINES (PARTICULARLY
UP THE HAINES HIGHWAY) AND JUST BELOW ADVISORY ELSEWHERE. WINDS
WILL ALSO BE UP ACROSS THE PANHANDLE AS THE FRONT COMES THROUGH
BUT I AM NOT EXPECTING ANY STRONG WIND HEADLINES TO BE NEEDED AT
THIS TIME.

 BEHIND THIS FRONT, THE PARENT LOW REMAINS PERSISTENT IN THE
NORTHERN GULF THROUGH THE WEEKEND SENDING SHOWERS ACROSS THE
AREA. THE ATMOSPHERE SHOULD BE COLD ENOUGH THAT MOST OF THE
SHOWERS WILL BE SNOW. AREAS IN THE SOUTHERN PANHANDLE WILL SEE
MORE OF A MIX, PARTICULARLY DURING THE DAY, AS TEMPS ALOFT WILL
BE COLD BUT SURFACE TEMPS MAY BE WARMED UP ENOUGH BY THE SUN THAT
ANY SNOW WILL MELT BY THE TIME IT REACHES THE GROUND.

 BEYOND SUNDAY MODEL AGREEMENT FALLS APART AS WE HAVE A PATTERN
SHIFT ALOFT FROM A TROUGH/RIDGE PATTERN TO MORE ZONAL FLOW. AT
THIS POINT THE MODELS ARE THEN TRYING TO PINPOINT THE NEXT FAST
MOVING SYSTEM FOR EARLY NEXT WEEK, BUT ARE NOT DOING WELL AT
AGREEING. AT THIS POINT WENT MAINLY FOR HPC DATA TO GET A GOOD
MIDDLE GROUND FOR THE EXTENDED FORECAST. FORECAST CONFIDENCE IS
ABOUT AVERAGE.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ042-043-051-052.
         SMALL CRAFT ADVISORY FOR PKZ021-022-033-035-036-041.

&&

PRB/EAL