Gale Warning 384, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
1100 AM AST SUN DEC 30 2007

.SYNOPSIS...
.SHORT RANGE...AT 1900 UTC A WEAK UPPER LEVEL TROUGH OVER THE SE
AK COASTAL WATERS IS MOVING ONSHORE ACROSS THE PANHANDLE AS A
RIDGE BUILDS IN THE EASTERN GULF.  CONVECTION HAS INTENSIFIED
OFFSHORE AND THE SHOWERS ARE BECOMING MORE ORGANIZED IN BANDS AS
THE TROUGH NEARS THE COAST.  RADAR AND SURFACE OBSERVATIONS
INDICATE ISOLATED CELLS WITH HEAVY PRECIPITATION...MAINLY AS
SNOW.  SHOWERS WILL INCREASE ACROSS THE SOUTHERN TWO THIRDS OF SE
AK THIS AFTERNOON AS THE TROUGH PASSES THEN TAPER OFF TONIGHT.

DEVELOPMENT IS UNDERWAY FOR THE INTENSE STORM IN THE PACIFIC THAT
IS EXPECTED TO DEEPEN TO 960 MB AROUND 650 NM SOUTHWEST OF SITKA
BY MONDAY AFTERNOON.  THE STORM WILL CONTINUE MOVING SLOWLY
NORTHEASTWARD TOWARD THE EASTERN GULF OF AK THROUGH THE REMAINDER
OF MONDAY SETTING UP A STRONG NORTHEASTLY OFFSHORE GRADIENT
ACROSS THE PANHANDLE.  EASTERLY WINDS IN THE SOUTHERN OUTSIDE
WATERS ARE EXPECTED TO REACH STORM FORCE BY LATE MONDAY.
DOWNSLOPE DRYING OVER THE INSIDE WATERS AND THE EASTERN GULF
COAST WILL LIMIT PRECIPITATION THROUGHOUT THE DAY. CFD

.LONG RANGE...MODELS ARE GENERALLY GOOD IN AGREEMENT.  12Z MODEL
RUN SHOWS A BETTER BEHAVIOR ESPECIALLY FOR THE SECOND HALF OF THE
LONG TERM FORECAST PERIODS.  THE GFS FAMILY WILL BE SELECTED ONCE
AGAIN TO MAINTAIN RUN TO RUN CONSISTENCY.  AN AMPLIFIED UPPER
RIDGE OVER THE PANHANDLE DRIFTS EAST AWAY FROM THE AREA ON NEW
YEARS EVE AS A STRONG CUT-OFF LOW MOVES IN SOUTH CENTRAL GULF.

THE LEADING EDGE OF THE FRONTAL BOUNDARY ARRIVES THE AREA AS
EARLY AS NEW YEARS EVE.  THUS CLOUDINESS AND POPS INCREASE FROM
THE SOUTH ACCORDINGLY THROUGH TUESDAY NIGHT.  SUFFICIENT MOISTURE
WILL CONTINUE TO FEED OVER HYDER ZONE THROUGH THURSDAY MORNING.
THIS IMPRESSIVE UPPER LOW SLOWLY FILLS AND MOVES INTO EASTERN
GULF WEDNESDAY THEN BECOMES A TROUGH THURSDAY OVER THE OUTSIDE
WATERS.

A STRONG SURFACE LOW AND FRONT ASSOCIATED WITH THE PROGRESSIVE
UPPER LOW WILL GENERATE STORM FORCE WINDS OVER OUTSIDE WATERS AND
VERY WINDY CONDITIONS ACROSS THE COASTAL ZONES ON NEW YEARS EVE
AND NEW YEARS DAY.  PRESSURE GRADIENT SHOULD BE TIGHT ENOUGH TO
PRODUCE GALE FORCE WINDS FOR THE INSIDE WATERS AS WELL.  12Z RUN
MTNWV EVEN HINTS A POSSIBLE SHORT DURATION OF TAKU WIND ON NEW
YEARS DAY.  WILL KEEP THE INHERITED WIND GRIDS FOR THE EARLY
PORTIONS OF THE LONG TERM FORECAST PERIODS.

ONSHORE FLOW WILL RETURN SATURDAY AND SUNDAY AS THE LOW BECOMES A
RESIDUAL OVER NORTH EASTERN GULF.  AK-GFS 850 MB TEMPERATURE
SHOWS A LITTLE WARMING TREND THROUGH THURSDAY THEN SUBSTANTIAL
COOLING OVER THE WEEKEND.  THE NEXT SHORTWAVE TROUGH IN THE
UPSTREAM MOVES INTO EASTERN GULF SATURDAY THEN DRIFTS EAST ACROSS
THE PANHANDLE THROUGH SUNDAY NIGHT. AHN

.AJK...WATCHES/WARNINGS/ADVISORIES
PUBLIC...NONE.
MARINE...STORM...PKZ310 LATE MON.
      ...GALE...PKZ034-035-036-041>043-051-052 LATE MON.
      ...SCA...RMNDR AREA.