Gale Warning 248, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
1237 PM AKDT MON OCT 13 2008

.SHORT TERM...SFC/UPR TROF WILL MOVE ACROSS SE AK THIS AFTERNOON
AND EVENING. A WARM OCCLUDED FRONT WILL MOVE INTO THE EASTERN
GULF TONIGHT...THEN DRIFT SLOWLY INTO SE AK TUE...STALLING OVER
THE N-CENTRAL PANHANDLE BY LATE AFTERNOON. LOW PRESSURE WILL
DEVELOP OVER THE AKPEN TODAY AND MOVE TO JUST S OF THE KENAI
PENINSULA BY LATE TONIGHT...THEN DRIFT TO JUST S OF PRINCE
WILLIAM SOUND TUE.

MAIN FORECAST ISSUE WILL BE TIMING THE TRANSITION OF PRECIP FROM
SHOWERY TO STRATIFORM. THE TRANSITION WILL LIKELY BE SOMEWHAT
DIFFICULT TO HIT EXACTLY DUE TO LOWER LEVELS REMAINING UNSTABLE
THRU TONIGHT WHILE MODERATE TO STRONG WARM ADVECTION OCCURS ALOFT.
WILL LIKELY SEE THE MORE STRATIFORM PRECIP ELEMENTS MOVE IN OVER
THE TOP OF SHALLOW SHOWERS UNDERNEATH LATE THIS EVENING ALONG THE
NW COAST (WHICH SHOULD BE EASY TO NOTICE ON THE RADAR NEAR PASI
LATE THIS EVENING TONIGHT)...WITH THIS TRANSITION MOVING EWD LATE
TONIGHT AND EARLY TUE. WILL INDICATE A TRANSITION TO STRATIFORM
BASED ON THE ABOVE TIME TABLE.

BEFORE THE TRANSITION...SFC/UPR TROF WILL BRING SOME LOCALLY
HEAVY SHOWERS TO THE AREA THIS AFTERNOON INTO EARLY EVENING...THEN
THEY SHOULD DIMINISH IN COVERAGE AND INTENSITY AS THE TRANSITION
TO STRATIFORM COMMENCES. THERE COULD BE SOME LOCALLY HEAVY RAIN
OVER THE NE GULF COAST LATE TONIGHT AND TUE...WITH THIS REACHING
THE N-CENTRAL PANHANDLE DURING THE DAY TUE. DO NOT ANTICIPATE ANY
HYDRO ISSUES WITH THIS RAIN THROUGH TUE AS LOCAL STREAMS AND
RIVERS HAVE RECOVERED FROM PREVIOUS HEAVY RAINS THIS LAST WEEKEND.

FOR THE MARINE FORECAST...SHOULD BE GENERALLY SCA WINDS OVER THE
OUTER WATERS AND INNER CHANNELS AS THE FRONT MOVES IN LATE TONIGHT
AND TUE. WILL LIKELY HAVE A SMALL AREA OF GALE FORCE WINDS ALONG
THE N GULF COAST TONIGHT AS A WEAK BARRIER JET DEVELOPS. LYNN
CANAL WILL LIKELY REMAIN IN SCA LEVEL WINDS EVEN BEFORE THE FRONT
ARRIVES DUE TO CROSS BARRIER FLOW MAINTAINING A SFC TROF OVER THE
YUKON...KEEPING A MODERATE S PRESSURE GRADIENT THERE.

.LONG TERM...THIS MORNING MODEL RUN IN FAIR AGREEMENT TILL THE
MIDDLE TO THE END OF THE WEEK. DID HAVE A LITTLE DIFFERENCES ON
THE TRAILING WAVE DEVELOPING OF THE FRONTAL BOUNDARY MOVING ON
TUESDAY AND STALLING OVER THE SOUTH CENTRAL PANHANDLE. 12Z GFS HAD
A MUCH STRONGER AND FURTHER WEST LOW CURVING BACK INTO THE
NORTHERN GULF BY WEDNESDAY AFTERNOON. HAVE GONE WITH THE WEAKER/
FURTHER EAST SOLUTIONS OFFERED BY THE NAM/ECMWF. SO EXPECT THAT
THE FRONTAL BOUNDARY WILL DRIFT BACK NORTH ON WEDNESDAY TO THE
NORTHERN PANHANDLE. THE FRONT SHOULD PUSH EAST INTO CANADA
THURSDAY THEN. THE UPPER LEVEL LOW OVER THE NORTHERN GULF WILL
HANG ON WEAKENING INTO FRIDAY BEFORE THE NEXT LOW MOVES ACROSS THE
NORTH PACIFIC AND SOUTHERN GULF...THEN INTO THE EASTERN GULF BY
MONDAY MORNING.

THERE IS A FAIR AMOUNT OF SPREAD IN THE EXTENDED FORECAST MODELS.
AFTER COORDINATING WITH ANCHORAGE AGREED THAT SINCE ALL OF THE
MODELS WERE INDICATING SOME SORT OF A LOW INTO THE EASTERN HALF OF
THE GULF BY LATE SUNDAY/EARLY MONDAY THAT WE WOULD DO AN
ADJUSTMENT TO OUR CURRENT FORECAST PACKAGE. SO WE HAVE ADJUSTED
THE WEEKEND FORECAST TOWARDS THE HPC GUIDANCE. WILL HAVE TO KEEP
AN EYE ON THIS SYSTEM...AS MOST MODELS WAVERING ON STRONG GALE TO
AREAS OF STORMS OVER THE GULF...AND THE SOME DIFFERING POSITIONS
AS WELL.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ052.
         SMALL CRAFT ADVISORY FOR PKZ011>013-021-022-031>036-041>043-051.

&&

RWT/BEZENEK