Gale Warning 12, NWS Juneau, AK

482 
FZAK67 PAJK 260606 AAA
OFFAJK

OFFSHORE WATERS FORECAST...UPDATED
NATIONAL WEATHER SERVICE JUNEAU AK
906 PM AKST TUE JAN 25 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.

PKZ398-261400-
906 PM AKST TUE JAN 25 2011
.SYNOPSIS FOR THE EASTERN GULF OF ALASKA...
A GALE FORCE LOW WILL MOVE NE INTO THE EASTERN GULF TONIGHT AND
INTO THE YUKON TOMORROW. THE ASSOCIATED WEATHER FRONT WILL MOVE
ACROSS SE ALASKA THROUGH TOMORROW. 

$$

PKZ310-261400-
GULF OF ALASKA NORTH OF 55 DEGREES NORTH AND EAST OF 144 DEGREES
WEST-
906 PM AKST TUE JAN 25 2011

UPDATED

.TONIGHT...SW WIND 30 KT. SEAS 17 FT.
.WED...SW WIND 25 KT. SEAS 16 FT. SW SWELL.
.WED NIGHT...W WIND 25 KT. SEAS 14 FT. SW SWELL. 
.THU...W WIND 25 KT. SEAS 12 FT. SW SWELL. 
.THU NIGHT...E WIND 20 KT. SEAS 10 FT. SW SWELL. 
.FRI...E WIND 25 KT. SEAS 10 FT. SW SWELL. 
.SAT...E WIND 20 KT. SEAS 14 FT. 
.SUN...SE WIND 20 KT. SEAS 11 FT. 

$$

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
1211 PM AKST TUE JAN 25 2011

.SHORT TERM...EARLY AFTERNOON SATELLITE REVEALS ANOTHER
STRENGTHENING GALE FORCE LOW IN THE NORTHEASTERN PACIFIC HEADED
NORTHWARD TOWARD THE PANHANDLE WITH ITS ASSOCIATED FRONTAL
BOUNDARY POISED TO MOVE ACROSS THE PANHANDLE TONIGHT. RAIN
CONTINUES TO OCCUR THROUGHOUT THE PANHANDLE ASSOCIATED WITH
ANOTHER DISSIPATING FRONTAL BOUNDARY FROM THE DEPARTING LOW NOW
NORTH OF PRINCE WILLIAM SOUND. THE MAIN FORECAST PROBLEM THROUGH
THE SHORT TERM PERIOD WILL BE THE LOCALLY STRONG WINDS ACROSS THE
OUTER COAST AND SOUTHERN PANHANDLE TONIGHT WITH THE SECOND WRAP
OF STRONG WINDS MOVING NORTHWARD ACROSS THE PANHANDLE TOMORROW
MORNING. THE 12Z GFS AND UKMET WERE DOING THE BEST JOB
INITIALIZING THE GALE FORCE LOW NOW IN THE NORTHEAST
PACIFIC...WITH THE 12Z NAM/ECMWF SOLUTIONS BEING TOO SLOW AND
WEAK GIVEN THE SATELLITE REPRESENTATION AND SO USED THE 12Z
GFS/UKMET FOR THE BASES OF THE SHORT TERM FORECAST. FORECAST
CONFIDENCE IS ABOVE AVERAGE THROUGH THE SHORT TERM PERIOD.

 FOR TONIGHT WILL SEE ANOTHER BAND OF STRONG WINDS MOVE ACROSS
THE SOUTHERN PANHANDLE AND OUTER COAST WITH THE 850 MB LLJ NEAR
55 KNOTS. AM CONCERNED FOR WIND ADVY GUSTS FOR KETCHIKAN AND
SOUTHERN BARANOF ISLAND AND WILL WATCH THE TRENDS IN OBSERVATIONS
AND THE 18Z MODEL RUNS...BUT ATTM WILL KEEP WINDS WITH GUSTS TO
35 MPH FOR AKZ028 AND AKZ023. WITH THE 850 MB WINDS BECOMING MORE
SOUTHERLY INTO TONIGHT AND THE UPPER LEVEL JET MOVING OVER THE
SOUTHERN PANHANDLE WILL HAVE LOCALLY HEAVY RAINFALL...ESPECIALLY
NEAR KETCHIKAN WITH 2 TO 3 INCHES IN 12 HOURS. WITH NO REAL
CHANGE IN THE AIRMASS ACROSS THE PANHANDLE INTO TONIGHT...THE
SNOW LEVELS WILL REMAIN CONSTANT NEAR 1000 TO 1500 FEET ACROSS
THE NORTHERN PANHANDLE WITH THE ONLY PLACES RECEIVING SNOWFALL
REMAINING ALONG THE NORTHERN ROADWAYS. WITH THE STRONG SOUTHERLY
WINDS RETURNING BY EARLY WEDNESDAY MORNING ACROSS THE NORTHERN
PANHANDLE AND THE BEST MID LEVEL PVA ACROSS THE SOUTHERN
PANHANDLE DID KEPT SNOW AMOUNTS BELOW ADVY FOR THE NORTHERN
ROADWAYS.

 FOR TOMORROW WILL SEE PERIODS OF RAINFALL CONTINUE THROUGHOUT
THE PANHANDLE WITH THE HIGHEST RAINFALL AMOUNTS ACROSS THE
EASTERN INNER CHANNELS AND ALONG CLARENCE STRAIT. WILL SEE CAA AT
MID LEVELS ADVECT INTO THE EASTERN GULF AND ALONG THE OUTER COAST
BY TOMORROW AFTERNOON AND THAT WILL LEAD TO THE ENVIRONMENT
BECOMING MORE CONVECTIVE WITH PRECIP BECOMING SHOWERY IN NATURE.
COULD SEE SOME ICE PELLETS MIX WITH RAINFALL NEAR THE STRONG
SHOWERS TOMORROW BUT INSTABILITY PARAMETERS CONTINUE TO REMAIN
RELATIVELY LOW AND SO AM NOT EXPECTING THUNDERSTORM ACTIVITY.
STRONG WINDS WILL CONTINUE TO MOVE NORTHWARD ACROSS THE PANHANDLE
THROUGH TOMORROW AFTERNOON WITH A STRONG SOUTHERLY PRESSURE
GRADIENT DEVELOPING BEHIND THE SURFACE LOW AS IT MOVES INTO THE
YUKON. WILL HAVE AT LEAST SMCR WINDS IN CROSS SOUND AND POINTS
NORTHWARD WITH WIND ADVY GUSTS POSSIBLE NEAR SKAGWAY. THE 850 MB
LLJ WINDS WILL BECOME SOUTHWESTERLY TOMORROW ACROSS THE CENTRAL
AND NORTHERN PANHANDLE AND THAT WILL AID IN THE STRONG WINDS
REACHING SKAGWAY ALONG WITH POSSIBLE LOW LEVEL TURBULENCE FROM
JUNEAU NORTHWARD.

&&

 .LONG TERM...EXTENDED FORECAST IS A BIT COMPLICATED TODAY AS
MODEL VARIABILITY IS VERY LARGE PAST SATURDAY. IN THE MID RANGE
HOWEVER, MODEL AGREEMENT IS STILL REASONABLE. LINGERING SHOWERS
FROM WEDNESDAY'S SYSTEM WILL STILL BE OVER THE MOST OF THE AREA
ON THURS, BUT INCREASING OFFSHORE FLOW AS A 500 MB RIDGE SET UP
IN THE EASTERN GULF WILL BE STARTING TO DRY US OUT BY THURS
NIGHT. FRIDAY IS LOOKING DRY AS OFFSHORE FLOW INCREASES IN
INTENSITY. IN ADDITION TO THE DRYER WEATHER A BRIEF PERIOD OF
MINOR OUTFLOW WINDS ACROSS THE AREAS IS POSSIBLE. HOWEVER, THE
COLD AIR IN THE INTERIOR OF CANADA WILL NOT BE VERY STRONG NOR
WILL IT BE VERY DEEP SO MOST OF THE WIND WILL BE CAUSED BY THE
PRESSURE GRADIENT RATHER THEN COLD AIR SPILLING OVER THE
MOUNTAINS. AREAS NEAR DOWNTOWN JUNEAU MAY ALSO BE IN LINE FOR A
MINOR MOUNTAIN WAVE EVENT ON FRIDAY. CRITICAL LEVEL LOOKS TO BE
RISING TO AROUND 600 MB WITH A CROSS BARRIER FLOW OF 10 TO 20 KT.
A SLIGHT TEMPERATURE INVERSION MAY ALSO BE PRESENT WITH THE WINDS
BLOWING OUT OF THE CANADIAN INTERIOR. IN EITHER CASE IT DOES NOT
APPEAR THAT WINDS WILL GET UP TO ADVISORY CRITERIA.

 BY SATURDAY, MODEL AGREEMENT BEGINS TO FALL APART AS THEY START
TO DEBATE ON WHERE A 500 MB RIDGE AXIS WILL SET UP. THE
DIFFERENCES ARE MOSTLY FOCUSED ON WHETHER THE AXIS WILL BE EAST
OR WEST OF THE PANHANDLE, BUT THAT RESULTS IN TWO VERY DIFFERENT
WEATHER SCENARIOS FOR THE AREA. THE GFS IS FAVORING A MORE
EASTWARD POSITION WHICH IS THE WETTER OF THE TWO SCENARIOS. THIS
POSITIONING KEEPS US IN LINE TO KEEP RECEIVING WEAK SHORT WAVES
AS THEY COME ACROSS THE GULF AND DUMP THEIR PRECIP ON THE
PANHANDLE. THE EC ON THE OTHER HAND KEEPS THE RIDGE AXIS OVER THE
EASTERN GULF. THIS RESULTS IN A BLOCKING PATTERN THAT SENDS THE
WEAK WAVES INTO SW AND SOUTH CENTRAL ALASKA AND KEEPS THE
PANHANDLE DRY INTO MID WEEK NEXT WEEK. OF THE TWO SCENARIOS THE
EC WAS THE MORE BELIEVABLE AS IT HAD BETTER RUN TO RUN
CONSISTENCY WHILE THE GFS WAS WILDLY VARIABLE WITH WHERE IT WAS
PLACING ITS VARIOUS SHORT WAVES BETWEEN RUNS.

 FOR THE FORECAST DECIDED TO USE GFS/UK FOR THE MID RANGE UPDATES
UP TO FRIDAY WHERE THE EC AND HPC TOOK OVER. FORECAST CONFIDENCE
IS GOOD TO FRIDAY NIGHT THEN DROPS TO POOR FROM SATURDAY ONWARD.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...WIND ADVISORY UNTIL 9 PM AKST THIS EVENING FOR AKZ027.
MARINE...GALE WARNING FOR PKZ036-041-042.
         SMALL CRAFT ADVISORY FOR PKZ021-022-033>035-043-051-052.

&&

PSS/EAL