FXAK67 PAJK 201503
AFDAJK
SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
603 AM AKST TUE JAN 20 2009
.SHORT TERM...THE STRONG RIDGE ACROSS WESTERN CANADA IS NOW
WEAKENING AND MOVING OFF THE THE EAST. AN UPPER LEVEL TROUGH
ACROSS THE WESTERN GULF IS PUSHING EASTWARD AND GAINING SUPPORT
FROM A SHORT WAVE MOVING ACROSS ALASKAN INTERIOR IN NORTHERN
BRANCH OF JET STREAM. THIS TROUGH EXPECTED TO MOVE ACROSS
SOUTHEAST ALASKA TONIGHT. THE FRONTAL BOUNDARY OVER THE EASTERN
GULF WILL MOVE ONSHORE THE NORTHERN PANHANDLE BY THIS EVENING AND
MOVE THROUGH CENTRAL AND SOUTHERN ZONES BY LATE TONIGHT. HIGH
PRESSURE WILL BUILD INTO THE YUKON LATE TONIGHT AND WILL START TO
BRING IN COLDER AIR TO FAR NORTHERN PANHANDLE. USED THE 00Z NAM12
FOR GRIDS.
RAIN HAS ALREADY SPREAD ACROSS NORTHERN HALF OF SOUTHEAST ALASKA
THIS MORNING WITH RADAR SHOWING SOME ECHOS STARTING TO MOVE INTO
SOUTH CENTRAL AREA. THE LONG SOUTHERLY FETCH OF MOISTURES WITH THE
FRONT IS STARTING TO WEAKEN AND EXPECT IN GENERAL LIGHT RAIN UNTIL
THE FRONT MOVES THROUGH WHEN WILL LIKELY SEE A BURST OF MODERATE
RAIN. CLOUDS INCREASING ACROSS SOUTHERN ZONES TODAY WITH RAIN
LIKELY TONIGHT.
HAVE EXTENDED WINTER WEATHER ADVISORY FOR THE KLONDIKE HIGH UNTIL
MIDNIGHT WHEN FRONT MOVES THROUGH. EXPECT AN ADDITION 4 TO 7
INCHES ABOVE 2000 FOOT LEVEL WITH LIGHTER AMOUNTS AT LOWER
ELEVATION LATE TONIGHT WHEN SNOW LEVELS FALL TO AS LOW AS 500 FEET
IN HAINES AREA TO 1000 FEET NEAR JUNEAU.
OVERALL GRADIENTS EXPECTED TO REMAIN LIGHT THROUGH INNER CHANNELS
WITH WINDS LESS THAN SMCR. SE SMCR IN COASTAL AREAS TODAY SHIFTING
THE WEST TONIGHT.
.LONG TERM...MAJOR CHANGE SINCE LAST NIGHT IN THAT GFS NOW LOOKS A
LOT LIKE ECMWF DID 24 HRS AGO AND THE CURRENT ECMWF IS OFFERING
A COMPLETELY NEW AND UNIQUE SOLUTION. THEREFORE OPTED TO MAKE NO
CHANGES TO THE EXISTING PRESSURE OR WIND GRIDS AND FORECAST
CONFIDENCE BEYOND THURSDAY IS BELOW AVERAGE. 
UPDATED OTHER GRIDS USING GFS AS PRIMARY GUIDANCE. MINOR CHANGES
TO POP FIELDS. STILL MAKING SIGNIFICANT CHANGES TO DAILY MAX AND
MIN TEMP GRIDS WITH MINIMUM TEMPERATURES AROUND THE PANHANDLE NOW
EXPECTED TO BE OVERNIGHT THURSDAY INTO FRIDAY MORNING. THE
STRENGTH OF THE HIGH DEVELOPING OVER THE NORTHERN INTERIOR REMAINS
FAIRLY CONSISTENT FROM MODEL RUN TO RUN AND IS THE SOURCE OF THE
COLD AIR WHICH WILL BEGIN PENETRATING THE PANHANDLE WEDNESDAY
NIGHT. THE HIGH WILL ALSO BRING WITH IT STRONG NORTHEASTERLY
PRESSURE GRADIENT THAT LOOKS LIKE WILL PRODUCE WIND ADVISORIES FOR
THE PUBLIC ZONES NORTH OF ICY STRAIT WEDNESDAY NIGHT THROUGH
THURSDAY. DURING THIS TIME...AM ALSO EXPECTING NORTHERLY GALES
OVER THE THE NORTHERN INNER CHANNELS. MAX CONDITIONS FOR THE
CENTRAL AND SOUTHERN INNER CHANNELS WILL LAG BY ABOUT ONE DAY AND
ARE EXPECTED TO BE MAX SMALL CRAFT TO MARGINAL GALE FORCE. BY NEXT
WEEKEND...THE HIGH WILL STILL BE CENTERED OVER CENTRAL BRITISH
COLUMBIA...BUT WILL BEGIN WEAKENING AND DRIFTING SOUTHEAST.
IN TERMS OF PRECIPITATION...THE LONG TERM FORECAST BEGINS WITH THE
TAIL END OF FRONT AND ASSOCIATED PRECIPITATION MOVING ACROSS THE
COAST MOUNTAINS AND INTO CANADA WEDNESDAY MORNING. AFTER THAT...THINGS
SHOULD BE COLD AND DRY OVER A MAJORITY OF THE PANHANDLE THROUGH
FRIDAY AFTERNOON WHEN THE NEXT FRONT IS EXPECTED TO MAKE LANDFALL
ALONG THE OUTER COAST. RIGHT NOW...HAVE VERY LITTLE CLOUD COVER
WEDNESDAY NIGHT AND THURSDAY. SO OVERNIGHT LOWS MAY NEED TO BE
ADJUSTED DOWN ACCORDINGLY AND MOST LOCATIONS SHOULD GET A HEALTHY
DOSE OF SUNSHINE ON THURSDAY.
&&
.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...WINTER WEATHER ADVISORY UNTIL MIDNIGHT AKST TONIGHT FOR AKZ018.
MARINE...SMALL CRAFT ADVISORY FOR PKZ041>043-051-052. 
&&
$$
MM/FRITSCH