Small Craft Advisory 154, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
252 PM AKST FRI FEB 24 2012

.SHORT TERM...GENERALLY A QUIET NIGHT TONIGHT AND START TO THE
WEEKEND. THE LOW MOVING ONSHORE BRITISH COLUMBIA TO THE EAST OF
HAIDA GWAII WILL CONTINUE TO MOVE AWAY FROM THE PANHANDLE. THE
INVERTED TROUGH OF LOW PRESSURE EXTENDS NORTH NORTHWEST ALONG THE
COAST TOWARDS THE PRINCE WILLIAM SOUND AREA. CLEAR TO MAINLY
CLEAR SKIES WITH SOME CIRRUS AS THE CLOUDS TO MAJORITY OF THE
PANHANDLE. THE CLOUD MASS ASSOCIATED WITH THE LOW EXTENDS FROM
ROUGHLY SOUTHERN PRINCE OF WALES ISLAND NORTHEAST TO SOUTH OF
WRANGELL EASTWARD. CLOUDS IN THAT REGION WILL PERSIST AND SLOWLY
DIMINISH FROM THE NORTH AND WEST THROUGH SATURDAY MORNING. OVER
THE CENTRAL GULF SOME LOW LEVEL CUMULUS CLOUDS THAT ARE FORMED BY
THE CLOUDS STREETS OVER THE SOUTH CENTRAL GULF COAST WILL
CONTINUE TO STREAM SOUTHEAST OVER NIGHT.

 A FAIRLY TIGHT PRESSURE GRADIENT OVERNIGHT AND INTO EARLY
SATURDAY WILL KEEP MAX SMALL CRAFT LEVEL WINDS OVER MUCH OF THE
INNER WATERS...ALTHOUGH NORTHERN LYNN CANAL WILL SEE GALE FORCE
FOR MUCH OF TONIGHT BEFORE BEGINNING TO DIMINISH. THOUGH THIS
SHOULD FALL APART BY AFTERNOON TIME FRAME. A BAND OF GALE FORCE
WINDS WEST OF PRINCE OF WALES ISLAND WILL HANG AROUND THROUGH THE
EVENING BEFORE WEAKENING TONIGHT.

 PRECIPITATION SEEMS TO BE LIMITED TO MAINLY THE MISTY FJORDS
REGION TONIGHT... BUT AM NOT EXPECTING MUCH MORE THAN FLURRIES OR
SPRINKLES.

 &&

 .LONG TERM...MID RANGE MODELS ARE DOING RATHER WELL TODAY.
EXCEPT FOR SOME SMALL DIFFERENCES IN FRONTAL SPEED ON SUN NIGHT
AND MONDAY MOST FEATURES ARE WELL REPRESENTED AND AGREED UPON.
MAIN CONCERN IN THE MID RANGE TODAY IS THE ONSET OF PRECIP OVER
THE PANHANDLE SUN INTO MON AND HOW MUCH WE WILL GET OUT OF IT.
YAKUTAT WILL BE THE FIRST IN LINE STARING SUN WITH SNOW STARTING
SOMETIME MIDDAY AND CONTINUING INTO THE NIGHT. THE WIND AT
YAKUTAT WILL START OUT EAST BUT THEN SWITCH TO THE SE THEN SOUTH
THROUGH SUN EVENING. THIS WILL CAUSE THE SNOW TO START TO MIX
WITH RAIN SUN NIGHT BUT THE AIR MASS MAY STILL BE COLD ENOUGH
THAT THE MAIN PRECIP WILL REMAIN SNOW UNTIL MON AFTERNOON WHEN
TEMPS WARM UP ENOUGH FOR RAIN TO BECOME DOMINATE.

 THE REST OF THE PANHANDLE WILL START TO SEE THE PRECIP SUN
NIGHT. MOST PLACES WILL SEE THE PRECIP START AS SNOW SINCE
1000 TO 850 MB THICKNESS VALUES WILL BE BELOW 1290 OVER MOST OF
THE PANHANDLE. BY MONDAY MORNING THE SOUTHERN PANHANDLE AND THE
CENTRAL OUTER COAST WILL HAVE CHANGED OVER OR AT LEAST MIXED WITH
RAIN AS THE SOUTHERLY FLOW AHEAD OF THE FRONT PUSHES WARMER AIR
INTO THE PANHANDLE. ALONG THE ICE STRAIT CORRIDOR AND NORTHWARD
MAY HAVE ENOUGH COLD AIR THAT THEY STAY AS SNOW OR AT LEAST A
SNOW/RAIN MIX FOR MOST OF THE EVENT. SNOW AMOUNTS LOOK LIKE THEY
WILL BE THE MOST SIGNIFICANT AROUND YAKUTAT AND HAINES.

 FOLLOWING THIS FRONT THE PARENT LOW WILL TAKE UP RESIDENCE IN
THE NORTHERN GULF THROUGH THE REST OF THE WEEK. IT WILL FINALLY
WEAKEN AWAY BY FRIDAY. THIS PATTERN WILL CONTINUE W TO SW FLOW
INTO THE PANHANDLE BUT WILL ALSO DRAW DOWN COLD AIR FROM WESTERN
ALASKA AND SEND IT OVER THE GULF INTO THE PANHANDLE KEEPING US ON
THE COOL SIDE THROUGH THE REST OF THE WEEK. ANOTHER FRONT
APPROACHING THE PANHANDLE FOR EARLY NEXT WEEKEND WILL START TO
WARM THINGS UP AGAIN ON FRIDAY.

 LONG RANGE MODELS WERE IN DECENT AGREEMENT THROUGH THE PERIOD.
DECIDED TO GO WITH A EC/NAM BLEND IN THE MID RANGE DUE TO GOOD
INITIALIZATION AND CONSISTENCY WITH THE FRONTAL SPEED. EXTENDED
RANGE FORECAST WAS UPDATED WITH THE CURRENT HPC.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ012-041-042.
         SMALL CRAFT ADVISORY FOR PKZ011-013-021-022-031>036-043-051-053.

&&

BEZENEK/EAL