Gale Warning 15, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
1100 AM AST FRI JAN 4 2008

.SYNOPSIS...
.SHORT RANGE...LOCAL OBSERVATIONS THIS MORNING ARE INDICATING
SOME VERY ISOLATED SHOWER ACTIVITY IN A FEW PANHANDLE LOCATIONS.
THE MOST CONSISTENT PRECIP HAS BEEN IN THE KETCHIKAN AND HYDER
AREAS WITH RAIN AND SNOW RESPECTIVELY. MORE PERVASIVE HAVE BEEN
POCKETS OF LOW CLOUDS AND FOG WHICH HAVE CONTINUED THROUGH LATE
MORNING IN HOONAH AND YAKUTAT. THE THREAT OF FOG WILL CONTINUE
THROUGHOUT THE DAY OVER THE INNER CHANNELS AND RELATED COASTAL
LOCATIONS AS WELL AS YAKUTAT. LESS LOW CLOUDS AND FOG IN THE
FORECAST FOR TOMORROW MORNING DUE PRIMARILY TO LEES RADIATIONAL
COOLING AS CLOUD COVER MOVES BACK INTO THE AREA FROM THE WEST AND
SOUTH.

THERE WILL BE LARGE BREAKS IN THE CLOUD COVER OVER THE CENTRAL
AND NORTHERN ZONES TODAY AWAY FROM COASTAL AREAS BUT THESE BREAKS
WILL FEWER AS THE DAY GOES BY. A VERY STRONG LOW SOUTHWEST OF
VANCOUVER ISLAND IS PUSHING AN OCCLUDED FRONT AND ASSOCIATED
CLOUD MASS TOWARDS THE SOUTHERN PANHANDLE TODAY. LOW AND MID
LEVEL OVERCAST CONDITIONS ARE ALREADY OVER THE SOUTHERN ZONES.
PRECIPITATION FROM THIS FRONT WILL CLIP THE SOUTHEASTERN PORTION
OF THE PANHANDLE WITH RAIN NEAR THE COAST AND SNOW INLAND. AM
EXPECTING LIGHT SNOW OVER HYDER TO START TONIGHT AND ACCUMULATE 2
TO 3 INCHES THROUGH THE DAY TOMORROW. ELSEWHERE...VERY LITTLE
PRECIP THROUGH TOMORROW.

A FAIRLY STRONG NORTHERLY PRESSURE GRADIENT WILL DEVELOP TONIGHT
AND SMALL CRAFT WINDS OVER LYNN CANAL...STEPHENS PASSAGE AND
CLARENCE STRAIT ARE EXPECTED. SMALL CRAFT CONDITIONS WILL DEVELOP
FROM SOUTH TO NORTH AS FAR AS CAPE FAIRWEATHER IN THE COASTAL
MARINE ZONES TONIGHT THROUGH TOMORROW DUE TO SWELL INSTEAD OF
WINDS.

.LONG RANGE...MODELS ARE SHOWING A GOOD CONSENSUS THIS MORNING
THROUGH THE MEDIUM RANGE.  BEYOND MONDAY SOME INCONSISTENCIES
APPEAR BETWEEN THE OPERATIONAL MODELS AND THE
ENSEMBLES...ESPECIALLY IN THE SOUTH WHERE ENSEMBLE MEMBERS HAVE
MAXIMUM SPREAD.  WILL FOCUS ON THE 12Z GFS THROUGH 00Z
TUESDAY...THEN BLEND PARTS OF THE ECM AND GFS INTO THE CURRENT
GRIDS THROUGH EARLY DAY 6.

JET REMAINS SOUTH OF THE FORECAST AREA THROUGH THE BULK OF THE
LONG RANGE. MEANWHILE...A QUASI-STATIONARY UPPER LOW WILL SIT
OVER WESTERN ALASKA...OCCASIONALLY DROPPING SOUTHEASTWARD INTO
THE NORTHERN GULF/SOUTHEAST ALASKA. THE RESULT WILL BE THAT MANY
OF THE FAST MOVING SYSTEMS RIDING ALONG THE JET WILL REMAIN SOUTH
OF THE FORECAST AREA.  WE DO SEE SOME BUCKLING ON SUNDAY
NIGHT/MONDAY WHICH WILL DIRECT A FAIRLY POTENT LOW TOWARDS THE
SOUTHERN PANHANDLE.  AS MENTIONED EARLIER...OPERATIONAL MODELS
SHOW SIMILAR SOLUTIONS...HOWEVER THERE IS WIDE SPREAD AMONGST
ENSEMBLE MEMBERS DURING THIS TIME.

SYNOPTICALLY...AN ELONGATED RESIDUAL LOW IN THE SOUTHEASTERN GULF
WILL SPLIT ON SUNDAY WITH A LOBE MOVING INTO THE SOUTHERN
PANHANDLE WHILE THE MAIN LOW MOVES INTO THE NORTHERN GULF. THE
LOBE DISSIPATES SUNDAY NIGHT AS A FAIRLY POTENT LOW DEEPENS ALONG
THE JET NEAR 45N 150W.  THE BUCKLING JET SWINGS THIS LOW
NORTHEASTWARD ACROSS THE QUEEN CHARLOTTES MONDAY NIGHT AND
TUESDAY WHERE IT WEAKENS NEAR HECATE STRAIT.  EXPECT STRONG WINDS
AND THE BULK OF THE PRECIPITATION ACROSS THE SOUTHERN COASTAL
ZONES AND SOUTHERN INNER CHANNELS.  BEYOND WEDNESDAY...MODELS
HINT A TRAILING LOW MOVING INTO THE EASTERN GULF THURSDAY
NIGHT...HOWEVER THE STRENGTH AND POSITION OF THIS LOW IS QUITE
UNCERTAIN.

TEMPERATURES ARE EXPECTED TO BE NEAR SEASONAL OR SLIGHTLY BELOW
THROUGH THE PERIOD.  THE COLDEST TEMPERATURES WILL ADVECT INTO
THE NORTHERN PANHANDLE SATURDAY NIGHT AND GRADUALLY MODIFY.
ANOTHER SHOT OF COLD AIR WILL SINK SOUTHWARD TUESDAY AND TUESDAY
NIGHT. OVERALL...EXPECT TEMPS TO BE COLD ENOUGH FOR SNOW IN THE
NORTH WHILE THE SOUTHERN COAST WILL SEE A GOOD MIX OF RAIN AND
SNOW.

.AJK...WATCHES/WARNINGS/ADVISORIES
PUBLIC...NONE

MARINE...SCA PKZ011>013-021>022-031>032-036

FCF/KJH