Small Craft Advisory 546, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
408 PM AKDT MON SEP 24 2012

.SHORT TERM...SOMEWHAT ACTIVE DAY ACROSS THE PANHANDLE WITH A
WEAK UPPER LEVEL TROUGH CURRENTLY MOVING THROUGH THE PANHANDLE.
FEATURE IS RATHER EASY TO ID IN SATELLITE IMAGES WITH ITS AXIS
EXTENDING FROM ABOUT MT. FAIRWEATHER SOUTH TO JUST OFFSHORE OF
BARANOF ISLAND. THIS FEATURE IS GENERATING SCATTERED SHOWERS
MAINLY IN THE NORTHERN PANHANDLE AND SOME BRIEF BREEZY CONDITIONS
IN A FEW PLACES AS IT MOVES THROUGH. FARTHER SOUTH SKIES HAVE
MORE BREAKS WHICH RESULTED IN AREAS OF DENSE FOG IN THE SOUTHERN
INNER CHANNELS THIS MORNING. THAT FOG HAS SINCE BURNED OFF.

INTO TONIGHT, SHOWERS WILL BE DIMINISHING AS THE UPPER TROUGH AND
ASSOCIATED VORTICITY MAX MOVE INTO CANADA THIS EVENING. SOME
LINGERING SHOWERS WILL STILL BE PRESENT IN THE NORTHERN PANHANDLE
INTO TOMORROW DUE TO THE CONTINUED ONSHORE FLOW ON THE NORTH SIDE
OF THE SURFACE RIDGE THAT IS BUILDING OVER THE AREA. FARTHER SOUTH
THE RIDGE WILL CONTINUE TO SUPPORT THE BREAKS IN THE CLOUDS AND
LIGHT WINDS SO THE POSSIBILITY OF FOG AGAIN TONIGHT IS RATHER
GOOD. AS SUCH I HAVE PUT AREAS OF FOG INTO THE FORECAST FOR LATE
TONIGHT AND EARLY TOMORROW FOR MOST SOUTHERN AREAS.

THINGS START GETTING INTERESTING TOMORROW, ESPECIALLY IN THE
GULF. OUR NEXT FRONT WILL BE TRACKING ITS WAY EAST SPREADING GALE
AND EVEN STORM FORCE WINDS AS IT COMES. THE STORM FORCE WINDS WILL
MAINLY BE ALONG THE NORTHERN GULF COAST TUE AFTERNOON DUE TO THE
USUAL BARRIER JET THAT WILL FORM THERE. WINDY CONDITIONS WILL ALSO
BE FORMING WEST OF YAKUTAT BAY BY TUE AFTERNOON AS WELL. RAIN WILL
ALSO BE STARTING TO SPREAD OVER THE AREA TUE AFTERNOON. YAKUTAT
WILL START GETTING THE RAIN AS SOON AS TUE MORNING. THE REST OF
THE OUTER COAST WILL BEGIN SEEING IT TUE AFTERNOON WITH THE REST
OF THE NORTHERN INNER CHANNELS BEGINNING TO GET RAIN BY TUE
EVENING.

SHORT RANGE MODELS ARE IN DECENT AGREEMENT THROUGH THE PERIOD.
WITH ONLY A FEW DIFFERENCES NOTED HERE AND THERE. DID NOT DO TOO
MANY CHANGES TO THE FORECAST OVERALL AS PREVIOUS FORECAST LOOK
QUITE LIKE THE CURRENT GUIDANCE. FORECAST CONFIDENCE IS ABOVE
AVERAGE.

.LONG TERM...STORM FORCE WINDS FOR THE NORTH GULF COAST ARE
DESCRIBED IN THE SHORT RANGE SECTION ABOVE. THIS FRONTAL SYSTEM
WILL MOVE ONSHORE THE NORTH AND EAST GULF COAST TUESDAY EVENING,
WITH A RELATIVE BREAK IN WINDS UNTIL WEDNESDAY AFTERNOON WHEN
AN EXPLOSIVELY CYCLOGENETIC SYSTEM IN THE WEST GULF SENDS A
MAX GALE FORCE INTO THE EAST GULF.

THE CONFIDENCE FOR THE LONG RANGE IS ABOVE AVERAGE. THE MODELS
HAVE A CONSENSUS FOR THE EXPLOSIVE CYCLOGENESIS REACHING ABOUT
954 MB ABOUT 120 NM SSE OF KODIAK OOZ THU. ALSO, THIS SYSTEM
THAT THE MODELS DEPICT FOR MIDWEEK IS ASSOCIATED WITH A POLAR
FRONT ZONE WAVE WE CAN ALREADY SEE ON THE GOES SIM IN THE VICINITY
OF 41N/156E. AGAIN, THE CONSENSUS IS GOOD WITH THE ECMWF TO GFS
FIELDS.

.AJK WATCHES/WARNINGS/ADVISORIES... PUBLIC...NONE.
MARINE...STORM WARNING FOR PKZ051-052. GALE WARNING FOR
PKZ022-041>043. SMALL CRAFT ADVISORY FOR PKZ021-033-036-053.

&&

EAL/JBT