Storm Warning 22, NWS Juneau, AK

542 
FZAK67 PAJK 210450 AAA
OFFAJK

OFFSHORE WATERS FORECAST...UPDATED
NATIONAL WEATHER SERVICE JUNEAU AK
750 PM AKST MON FEB 20 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.

PKZ398-211400-
400 PM AKST MON FEB 20 2012 
.SYNOPSIS FOR THE EASTERN GULF OF ALASKA...
A LOW IN THE WESTERN GULF WILL MOVE NE INTO THE NORTHERN GULF
THIS EVENING. THE ASSOCIATED FRONT WILL MOVE E ACROSS THE
PANHANDLE TONIGHT. A WEAK LOW WILL MOVE ACROSS THE SOUTHERN GULF
TUE AND INTO THE SOUTHERN PANHANDLE TUE EVENING. 

$$

PKZ310-211400-
GULF OF ALASKA NORTH OF 55 DEGREES NORTH AND EAST OF 144 DEGREES
WEST-
750 PM AKST MON FEB 20 2012 

UPDATED

...GALE WARNING TONIGHT...

.TONIGHT...SW WIND 40 KT DIMINISHING LATE. SEAS 24 FT. 
.TUE...SW WIND 30 KT DIMINISHING TO 20 KT IN THE AFTERNOON. SEAS 22
FT. SW SWELL IN THE AFTERNOON. 
.TUE NIGHT...W WIND 30 KT. SEAS 17 FT. 
.WED...W WIND 30 KT. SEAS 15 FT. 
.WED NIGHT...W WIND 25 KT. SEAS 16 FT. SW SWELL. 
.THU...NW WIND 20 KT. SEAS 12 FT. SW SWELL. 
.FRI...NW WIND 25 KT. SEAS 10 FT. 
.SAT...NW WIND 25 KT. SEAS 9 FT. 

$$

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
128 PM AKST MON FEB 20 2012

.SHORT TERM...CURRENT SATELLITE TODAY SHOWS A MODERATE STRENGTH
LOW IN THE WESTERN GULF JUST EAST OF KODIAK ISLAND. THE
ASSOCIATED FRONT EXTENDS OVER THE NORTHERN COAST AND INTO THE
EASTERN GULF. IT IS CURRENTLY BRINGING STRENGTHENING SOUTHERLY
WINDS AND SOME PRECIP TO THE AREA. FROZEN PRECIP IS OBSERVED
NORTH OF A LINE ROUGHLY FROM PELICAN TO TAKU INLET. THE SOUTHERLY
FLOW IS STARTING TO EAT AWAY AT THE COLD AIR IN THE PANHANDLE AS
TEMPERATURES ARE STARTING TO WARM ABOVE FREEZING IN JUNEAU,
GUSTAVUS, AND HOONAH. S TO SE WINDS ARE ALSO STARTING TO PICK UP
ALONG THE PANHANDLE.

 FOR TONIGHT THE FRONT WILL CONTINUE TO ADVANCE ACROSS THE GULF
AND MAKE ITS WAY ACROSS THE PANHANDLE THIS EVENING. WARM AIR
AHEAD OF IT WILL CONTINUE TO WORK ITS WAY UP THE PANHANDLE
CHANGING SNOW OVER TO RAIN AT MOST SEA LEVEL LOCATIONS INCLUDING
SKAGWAY AND HAINES. THE HIGHER ELEVATION LOCATIONS ALONG THE
HAINES AND KLONDIKE HIGHWAYS WILL REMAIN SNOW FOR MOST OF THIS
EVENT AS SUCH WINTER STORM WARNINGS REMAIN OUT UNTIL TOMORROW
MORNING FOR THESE LOCATIONS. WINDS WILL ALSO BECOME A BIT BREEZY
THIS EVENING AS THE FRONT MAKES ITS WAY THROUGH.

 BEHIND THE FRONT IS A 120 KT JET STREAK AT 500 MB TAKING AIM AT
THE CENTRAL OUTER COAST. I HAVE DECIDED TO PUT UP STRONG WIND
HEADLINES FOR SITKA AND ELFIN COVE AREAS FOR LATER TONIGHT.
BREEZY CONDITIONS WILL ALSO BE FELT FURTHER INLAND AS THE
SOUTHERLY PRESSURE GRADIENT INCREASES DUE TO AN APPROACHING WEAK
WAVE FROM THE SW. I HAVE PUT UP GALE WARNINGS FOR MOST OF THE
NORTH-SOUTH INNER CHANNELS FOR TOMORROW AS PRESSURE DIFFERENCES
REACH -4 MB BETWEEN JUNEAU AND SKAGWAY AND JUNEAU AND FIVE
FINGERS. SKAGWAY MAY ALSO SEE SOME STRONG WINDS FOR TOMORROW AS
WELL.

 SHORT RANGE MODELS WERE IN FAIR AGREEMENT FOR THE FIRST 12 HOURS
THEN START TO DEBATE ON HOW TO HANDLE THE NEXT SHORTWAVE COMING
UP FROM THE SW FOR TUES AFTERNOON. GFS AND EC SEEMED TO BE THE
ONLY TWO THAT COULD REACH SOME SORT OF AGREEMENT ON TRACK. THE UK
LOOKED TO BE TOO FAR NORTH AND THE NAM WAS TOO FAR SOUTH AND TOO
FAST. DECIDED ON USING A EC/UK BLEND FOR TONIGHT BASED ON HOW
WELL THEY INITIALIZED THE FEATURES TODAY. THEN USED A EC/GFS
BLEND FOR TOMORROW BASED ON THEIR AGREEMENT WITH EACH OTHER
THROUGH THAT PERIOD. FORECAST CONFIDENCE IS ABOUT AVERAGE.

.LONG TERM...MODEL AGREEMENT HAS DECREASED ON LARGE SCALE FLOW
CHANGE FOR UPCOMING LATE WEEK INTO EARLY NEXT WEEK TIME FRAME.
GFS DEVIATED FROM IDEA THAT LARGE SCALE RIDGE WOULD BUILD AND
REMAIN TO THE WEST OF THE AREA DURING THAT TIME. THE NEW ECMWF
DOES BRING THE RIDGE AXIS A BIT FURTHER EAST AROUND SUN BUT THEN
REDEVELOPS RIDGE BACK TO THE WEST EARLY NEXT WEEK. THINK MAIN
PROBLEM WITH GFS IS WAY IT HANDLES A CUT OFF LOW WELL TO THE SSW
OF THE AREA...SHOWING IT FURTHER N AND NOT ALLOWING AS MUCH
RIDGING TO REBUILD TO THE WEST EARLY NEXT WEEK. THIS LEADS TO
LARGE DIFFERENCE IN TEMPS AT THAT POINT...WITH GFS MUCH WARMER
THAN THE ECMWF. AT THIS POINT THINK BEST WAY TO GO IS TO KEEP THE
WEEKEND INTO EARLY NEXT WEEK PERIOD AS IS AND ALLOW THE MODELS TO
SORT THINGS OUT. DID USE A BLEND OF THE 12Z EC/GFS FOR TUE NIGHT
INTO FRI HOWEVER...MAINLY TO GET RID OF A LOW THAT WAS IN PREVIOUS
FORECAST AROUND THU THAT NO MODEL SHOWS AND FOR SMOOTH TRANSITION
FROM SHORT TERM.

A LOW WILL BE TRACKING ENE ACROSS THE SRN AREA TUE NIGHT. THIS
SYSTEM HAS COME IN WEAKER THAN PREVIOUSLY FORECASTED ON LATEST
MODEL RUNS. THE UPPER WAVE AND ASSOCIATED SFC LOW ARE FLAT AND
THIS WILL LIMIT NWD EXTENT OF PRECIP FROM THIS SYSTEM. WENT WITH
STEADY PRECIP OVER THE SERN HALF OF THE AREA AND SHOWERS OVER THE
NW HALF FOR TUE NIGHT. SHOWERS WILL DECREASE SOMEWHAT TUE NIGHT OVER
THE NORTH DUE TO SHORTWAVE RIDGING MOVING THRU THAT AREA. BY WED
MORE TROFFING SHOULD MOVE IN AND SHOWERS SHOULD INCREASE AGAIN.
TEMPS ALOFT WILL BE SLOWLY COOLING WED INTO WED NIGHT...AND PTYPE
WILL TRANSITION FROM RAIN SHOWERS TO SNOW SHOWERS DURING THAT TIME.
THU SHOULD BE MAINLY SNOW SHOWERS AS ONSHORE FLOW CONTINUES BUT
COVERAGE OF THE SHOWERS WILL LIKELY DECREASE AS FLOW ALOFT BECOMES
A BIT ANTICYCLONIC.

ANOTHER LOW WILL TRACK EWD WELL S OF THE AREA AND THIS WILL HELP
DEVELOP OFFSHORE FLOW THU NIGHT INTO FRI. ALSO...WILL START TO SEE
SOME COLDER AND DRIER AIR FILTER IN FROM THE N LATE FRI AND FRI
NIGHT.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...STRONG WIND FROM 9 PM AKST THIS EVENING THROUGH LATE TONIGHT FOR
     AKZ022-023.
         WINTER STORM WARNING UNTIL 9 AM AKST TUESDAY FOR AKZ018-019.
         WINTER WEATHER ADVISORY UNTIL 4 PM AKST THIS AFTERNOON FOR
     AKZ017.
MARINE...GALE WARNING FOR PKZ012-013-022-031-033-036-041>043-051-052.
         SMALL CRAFT ADVISORY FOR PKZ011-021-032-034-035-053.

&&

EAL/RWT