Small Craft Advisory 778, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
342 PM AKST MON NOV 28 2011

.SHORT TERM...SHORT RANGE FORECAST IS LOOKING RATHER QUIET FOR
THE NEXT 24 HOURS. LAST NIGHTS SYSTEM IS ON ITS WAY INTO CANADA
AT THE MOMENT BUT THE VERY SOUTHERN PART OF THE PANHANDLE HAS YET
TO EXPERIENCE FRONTAL PASSAGE. WARM ADVECTION AHEAD OF THE FRONT
WAS RELATIVELY STRONG AS MOST AREAS CHANGED OVER TO RAIN EARLY
THIS MORNING AFTER A PERIOD OF SNOW OVERNIGHT. THE EXCEPTION WAS
HAINES AND SKAGWAY WHERE COLD TEMPS AND NORTHERLY WINDS KEPT THE
PRECIP AS SNOW WELL INTO THE MORNING. BY LATE MORNING THE
SOUTHERLY PUSH FINALLY GOT TO HAINES AND SKAGWAY AS THEIR WIND
SWITCHED AROUND TO THE S OR SE AND THEIR TEMPERATURES WARMED UP
ABOVE FREEZING. THE BIG WINNER FOR SNOWFALL WAS HAINES WHERE
21 INCHES FELL OVERNIGHT. WINDS WERE ACTING UP TOO OVER NIGHT.
GUSTS UP TO 43 KT WERE RECORDED IN THE SOUTHERN PANHANDLE EARLIER
TODAY, JUNEAU HAD GUSTS UP TO 45 KT, AND ELDRED ROCK AND SKAGWAY
ARE CURRENTLY GUSTING TO 47 AND 39 KT RESPECTIVELY.

FOR TONIGHT AND TOMORROW, SHOWERS ARE EXPECTED TO CONTINUE WITH
SOME PERIODS OF MORE FREQUENT AND HEAVIER SHOWERS AS VARIOUS WEAK
WAVES MOVE THROUGH THE PANHANDLE. PRECIP TYPE IS EXPECTED TO
REMAIN MOSTLY RAIN THIS EVENING AS SOUTHERLY WINDS CONTINUE
THROUGHOUT THE PANHANDLE. THESE SHOWERS WILL START MIXING WITH
SNOW LATER TONIGHT AS TEMPERATURES COOL DOWN. THEN FOR TOMORROW
WINDS WILL DIMINISH AND WITH THE SLIGHTLY COLDER AIR ALOFT THAT
WILL COME IN TOMORROW THE SHOWERS WILL STILL BE A MIX OF RAIN AND
SNOW PARTICULARLY IN THE NORTHERN PANHANDLE. ANY SNOW
ACCUMULATIONS SHOULD BE LIGHT BUT HEAVIER SNOW SHOWERS MAY DROP A
FEW INCHES IN LOCALIZED AREAS.

WINDS WILL ALSO BE CALMING DOWN. ACROSS THE SOUTH GUSTY WINDS IN
ADVANCE OF THE FRONT WILL DIMINISH THROUGH THE AFTERNOON TODAY AS
THE FRONT PUSHES FARTHER TO THE EAST. IN THE NORTH, WINDY
CONDITIONS ARE EXPECTED IN THE N-S CHANNELS THIS AFTERNOON AND
TONIGHT. ELDRED ROCK IS ALREADY BLOWING GALE FORCE AND SKAGWAY HAS
SOUTHERLY GUSTS TO 45 MPH. THOSE WINDS WILL DIE DOWN BY TOMORROW
MORNING AS THE REMAINS OF THE NORTHERN GULF LOW MOVES FARTHER INTO
THE YUKON.

SHORT RANGE MODELS WERE NOT DOING TOO BADLY THIS MORNING. MOST OF
THEM DID INITIALIZE RATHER WELL. THE EXCEPTION WAS THE NAM WHICH
DID NOT REPRESENT SOME OF THE UPPER LEVEL FEATURES THAT WELL.
DECIDED TO STICK WITH THE EC AND UK WITH SOME GFS FOR WINDS FOR
FORECAST UPDATES. FORECAST CONFIDENCE IS ABOUT AVERAGE.

.LONG TERM...A STRONG AND MODERATELY WARM UPPER LEVEL RIDGE AND
ASSOCIATED SURFACE HIGH WILL BUILD FROM THE NORTHEAST PACIFIC AND
ACROSS SOUTHEAST ALASKA TUESDAY NIGHT AND WEDNESDAY AND TILT EAST
OF THE AREA THURSDAY. A 160 KT SW JET WITH A LONG FETCH OF
MOISTURE ORIGINATING FROM THE SUB TROPICS WILL RIDE NE ALONG BACK
SIDE OF THE RIDGE WED AND THURSDAY. THIS WILL BRING A SERIES OF
MILD AND WET WEATHER SYSTEMS OVER THE PANHANDLE. A SECOND AND THIRD
WAVE ARE ADVERTISED TO REACH THE AREA SATURDAY AND AGAIN NEXT MONDAY.

WITH HIGH PRESSURE OVER THE PANHANDLE TUESDAY NIGHT AND WEDNESDAY
WILL HAVE SOME PARTIAL CLEARING WHICH SHOULD ALLOW TEMPS TO DIP BELOW
FREEZING. STABILITY WILL LIMIT SHOWER ACTIVITY AND WILL ONLY KEEP
ISOLATED TO SCATTERED SHOWERS FOR NORTHERN HALF WITH NO POPS FOR
SOUTHERN. FOG WILL ALSO BE AN ISSUE.

FIRST WAVE WILL BRING WARMER TEMPS AND HEAVY RAIN TO PAYA ON
WEDNESDAY POSSIBLY TOTALING 4 INCHES IN 48 HRS. FREEZING LEVELS
ARE FORECAST TO CLIMB TO AROUND 3K NORTH TO 6 K SOUTH. THE FRONT
SLIDES EAST OVER SOUTHEAST ALASKA THURSDAY WHERE 1-2 INCHES OF
RAIN IS LIKELY. WILL HAVE A STRONG S TO SE PRESSURE GRADIENT
ACROSS COASTAL AREAS WEDNESDAY AND CONTINUING OVER THE INNER CHANNELS ON
THURSDAY. HAVE SOLID GALES FOR MOST MARINE AREAS AS FRONT MOVES
THROUGH AND WILL LIKELY NEED STRONG WIND HEADLINES FOR PUBLICS.

A BRIEF SHOT OF COLD AIR IN THE UPPER LEVELS MOVES OVER THE AREA
FROM THE WEST LATE THURSDAY WITH SCATTERED RAIN AND SNOW SHOWERS.
RIDGE REBUILDS QUICKLY BEHIND THE UPPER TROUGH BY EARLY FRIDAY
WITH NEXT SYSTEM OF SIMILAR STRENGTH MOVING THROUGH THE PANHANDLE
LATE FRIDAY INTO SATURDAY. A THIRD WAVE IS ADVERTISED TO MOVE INTO
THE NORTHEAST GULF ON MONDAY.

FAIRLY GOOD SYNOPTIC AGREEMENT BETWEEN MODELS WITH TYPICAL
DIFFERENCES IN TIMING, INTENSITY, AND POSITION OF INDIVIDUAL
WAVES. USED AN EC/GFS BLEND FOR WED-THU SYSTEM GOING TO HPC GRIDS
FOR REMAINDER OF LONG TERM.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...STRONG WIND UNTIL 9 PM AKST THIS EVENING FOR AKZ018.
MARINE...GALE WARNING FOR PKZ012-022.
         SMALL CRAFT ADVISORY FOR PKZ011-013-031-032-042-043-051-052.
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ041.

&&

EAL/MM