Gale Warning 1, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
341 PM AKST THU DEC 31 2009

.SHORT TERM...SATELLITE LOOP SHOWS MOSTLY CLOUD FREE SKIES
ACROSS THE FORECAST DOMAIN EXCEPT A FEW LINGERING MIDDLE TO HIGH
CLOUDS ALONG THE IMMEDIATE CENTRAL AND SOUTHERN COASTAL AREAS. A
DEVELOPING LOW IN THE NORTHEAST PACIFIC PUSHES EXTENSIVE HIGH
CLOUDS OVER THE QUEEN CHARLOTTES INTO DIXON ENTRANCE. UNDER
PERSISTING SUBSIDENCE AND OFFSHORE FLOW...TEMPERATURES REMAIN ON
THE COLD SIDE RANGING IN THE MID TO UPPER TEENS NORTHERN AREAS TO
THE LOWER 30S COASTAL AND SOUTHERN AREAS. PERSISTING HIGH
PRESSURE OVER BRITISH COLUMBIA KEEPS TIGHT EASTERLY PRESSURE
GRADIENT AND GENERATES STRONG OUTFLOW WINDS ALONG THE COAST
MOUNTAINS WITH ADVISORY LEVEL WIND GUSTS OVER LYNN
CANAL...INTERIOR PASSES OF JUNEAU AND HYDER AREAS.

MODELS ARE IN FAIR AGREEMENT WITH THE HIGH PRESSURE OVER THE
NORTHWESTERN CANADA WEAKENS AS A DEVELOPING LOW IN THE NORTHEAST
PACIFIC MOVING TOWARDS BRITISH COLUMBIA COAST AND PUSHING A
FRONTAL BOUNDARY NORTHWESTWARD ACROSS THE EASTERN GULF THROUGH
TONIGHT. LINGERING CLOUDS ACROSS THE SOUTHERN MOST AREAS WILL MOVE
EAST AWAY FROM THE AREA TONIGHT. SKIES WILL REMAIN MOSTLY CLEAR
TONIGHT AND NEW YEARS DAY WITH STRONG RADIATION COOLING FOR
NOTICEABLE WIND CHILL ISSUES...ESPECIALLY ACROSS THE NORTHERN
PANHANDLE WITH EXPECTED SINGLE DIGIT OVERNIGHT LOWS.

WINDS ALONG LYNN CANAL IN HAINES AREA WILL DECREASE A BIT THIS
AFTERNOON BUT WILL PICK UP AGAIN EARLY THIS EVENING THEN CONTINUE
THROUGH EARLY TOMORROW MORNING...THUS EXTENDED THE WIND ADVISORY
ACCORDINGLY. AS THE HIGH PRESSURE WEAKENS A LITTLE TONIGHT AND
SLIGHTLY DRIFT NORTH...EXPECT DECREASING OUTFLOW OVER HYDER ZONE
TOMORROW MORNING...THUS KEPT THE WIND ADVISORY THROUGH MID MORNING
TOMORROW. RATHER THAN THAT...THE WIND ADVISORY FOR SKAGWAY AND
JUNEAU REMAINS AS IS THROUGH TOMORROW AFTERNOON.

.LONG TERM...CHANGES TO THE FORECAST PACKAGE ARE SMALL: THE
PATTERN IS GEN DRY, WITH WARMING NEXT WEEK DUE TO A LARGE-SCALE
CHANGE TO FLOW PATTERN TO OCCUR NEXT WEEK.

THE CONFIDENCE IN A WEEKEND SNOW EVENT IS LOW, AND IF IT DOES
OCCUR WILL HAVE MINIMAL AMOUNTS. THE SURFACE WINDS FOR 84 HRS AND
BEYOND HAVE BEEN MADE BY USING THE HPC PRESSURE FIELDS FROM THIS
MORNING. THE OVERALL MODEL CONSENSUS HAS BEEN IMPROVING FOR NEXT
WEEK, ALBEIT ABOUT 12Z THU THE CONSENSUS STILL BREAKS DOWN.

THE SHORT RANGE SECTION ABOVE DESCRIBES THE DEVELOPING LOW IN
THE NORTHEAST PACIFIC MOVING TOWARDS BRITISH COLUMBIA COAST.
SHORTLY AFTER 00Z SAT THE LANDFALLING LOW WILL ALLOW A WEAK
ZONAL FLOW FROM A RIDGE ALOFT OVER THE CENTRAL GULF OF ALASKA.
THE RESULT WILL BE AN ONSHORE LIFT THAT WILL AT LEAST GENERATE
A CLOUDMASS FOR THE WEEKEND. THE MODELS HAVE A VARIETY OF
SOLUTIONS TO THE WEAK OVERRUNNING SNOW EVENT THAT IS POSSIBLE
FOR THIS WEEKEND. THE POP FIELDS HAVE NOT BEEN CHANGED FOR THIS
WEEKEND AS THE EVENT WOULD BE AT THE LOWER LIMITS OF WHAT THE
MODELS COULD DETECT.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...WIND ADVISORY UNTIL 4 PM AKST FRIDAY FOR AKZ018-025.
         WIND ADVISORY UNTIL 6 AM AKST FRIDAY FOR AKZ019.
         WIND ADVISORY UNTIL 9 AM AKST FRIDAY FOR AKZ029.
MARINE...GALE WARNING FOR PKZ011>013.
         SMALL CRAFT ADVISORY FOR PKZ021-022-031>036-041-043-051-052.
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ042.

&&

AHN/JBT