Gale Warning 383, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
1230 PM AST WED DEC 26 2007

.SYNOPSIS...
.SHORT RANGE...STRONG SURFACE LOW IN THE VICINITY OF DUTCH
HARBOR/COLD BAY AND ITS ASSOCIATED WEATHER FRONT STRETCHING
ACROSS THE GULF OF ALASKA WILL BE MAIN WEATHER FACTOR FOR OUR
AREA THROUGH THE SHORT TERM.  THE SURFACE LOW EXPECTED TO STAY
WEST OF 155 OR EVEN SHIFT TO THE BRISTOL BAY AREA IT WILL BE JUST
THE FRONTAL BAND STRETCHING AND SHEARING OVER THE GULF.

A WEAK CIRCULATION NEAR SITKA ON WEDNESDAY WILL BE DISSIPATING AS
THE UPPER LEVEL TROUGH IT IS IN MOVES EAST INTO WESTERN CANADA BY
WEDNESDAY EVENING. THE UPPER LEVEL RIDGE AHEAD OF THE INCOMING
SYSTEM LOOKS TO MOVE THROUGH SOUTHEAST ALASKA BY THURSDAY
MORNING.

BY THURSDAY MORNING THE FRONT SHOULD BE REACHING THE QUEEN
CHARLOTTE ISLANDS/PRINCE OF WALES ISLAND REGION. MODELS TRYING TO
INDICATE A TRIPLE POINT FEATURE ON THE FRONT BUT BUT THIS LOOKS
TO BE MOVING TOWARDS NORTHERN VANCOUVER ISLAND.  SHOULD SEE SOME
PRECIPITATION (MAINLY RAIN) SPREAD INTO THE CENTRAL/SOUTHERN
COASTAL AND SOUTHERN PANHANDLE THURSDAY... OTHERWISE I THINK
CHANCE POPS AT BEST FOR REMAINDER OF LAND ZONES.

WIND SHOULD BE THE BIG FORECAST THING THROUGH THURSDAY. ADVISORY
ON THE SOUTHERN COAST LOOK OKAY...A BIT CONCERNED ABOUT THE ZONE
28 ONE BUT WILL LEAVE IT FOR NOW.  GALES INTO THE OUTSIDE WATERS
AND SMALL CRAFT THE REST OF THE AREA.  OUT FLOW WINDS FROM THE
INTERIOR DUE TO THE PRESSURE GRADIENT WILL ALSO BE BLOWING
TOO...ALONG WITH ANY OF THE EAST-WEST MARINE PASSAGES.

.LONG RANGE...
GLOBAL MODELS HINTING AT A PATTERN CHANGE DURING THE EXTENDED
FORECAST PERIOD. LONG WAVE TROUGH ANCHORED NEAR DATELINE IS FCST
TO SHIFT EAST TO GULF AK BY END OF NEXT WEEK. RESULT FOR SE AK
WOULD BE COOLING TREND AND SEVERAL SNOW EPISODES DURING THE
TRANSITION. ALREADY SEEING SOME RUN TO RUN MODEL INCONSISTENCY
WITH THE PATTERN CHNAGE WHICH IS ALSO NOTED IN HPC DISCUSSIONS.
LEFT MOST OF EXISTING GRID FCSTS UNCHANGED BUT I DID MODIFY SAT
SFC PRESSURE FCST A BIT...ALONG THE LINES OF THE PREFERED 12Z
ECMWF ...WHICH REDUCES WIND SPEEDS OVER THE GULF MARINE ZONES AND
KEEPS POPS IN THE CHC-LIKELY CATAGORY OVER PANHANDLE.

NEXT SEVERAL FRONTAL SYSTEMS WILL SWEEP OVER EASTERN GULF
NEGATIVELY TILTED AS PARENT LOWS STAY OUT NR AK PENN. THUS DO NOT
EXPECT A LOT OF PRECIPITATION FOR INNER CHANNELS FRI-SAT WITH
SOME MODERATE RAIN POSSIBLE FOR SOUTHERN. PRECIPITATION ACROSS
THE NORTHERN TWO THIRDS EXPECTED TO STAY ALL SNOW WHILE COASTAL
AREAS MIX WITH RAIN. WITH THE UPPER TROUGH STAYING OFFSHORE...
W-SW FLOW ALOFT WILL MAINTAIN COOL ONSHORE FLOW AND KEEP THE AREA
MOSTLY CLOUDY. A POSSIBLE OVER RUNNING SNOW EVENT MAY DEVELOP
ABOUT NEW YEARS DAY. DEPENDING ON HOW MUCH COLD AIR SETTLES IN
OVER THE WEEKEND A BOUNDARY MAY FORM OVER NORTHERN-CENTRAL
PANHANDLE AND COULD BE FOCUS FOR SIGNIFICANT SNOW EVENT. HOWEVER
WILL NOT JUMP ON THIS POTENTIAL JUST YET DUE TO PREVIOUSLY
MENTIONED MODEL UNCERTAINTY AFTER THE WEEKEND.  TA

.AJK...WATCHES/WARNINGS/ADVISORIES
PUBLIC...WIND ADVISORY AKZ023-027-028
MARINE...GALE WARNING PKZ041>043-051-052-310
      ...SMALL CRAFT ADVISORY PKZ011-013-021-022-031>036