High Wind in Alaska, February 13, 2010

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
538 AM AKST SAT FEB 13 2010

.SHORT TERM...FOCUS IN THE SHORT TERM IS 953 MB STORM FORCE LOW
CURRENTLY NEAR 48N 142W THAT CONTINUES TO MOVE NORTH INTO THE
SOUTH CENTRAL GULF THROUGH THE DAY. SATELLITE IMAGERY REVEALING
OCCLUDED FRONT WRAPPED AROUND THE LOW AND EXTENDS EASTWARD TOWARD
QUEEN CHARLOTTE ISLAND.

 WIND TO BE THE PRIMARY CONCERN WITH THIS SYSTEM. THE WIND FIELD
ENCOMPASSES THE ENTIRE GULF AND AS IT CONTINUES TO MOVE NORTHWARD
AND THEN RE CURVES TO THE NORTHWEST TONIGHT WILL IT RAKE THE
OUTER COAST WITH STRONG WINDS. HHW FOR ZONE 27 AS A 75 KT TO
80 KT 850 MB LLJ MOVES NORTHWESTWARD ALONG THE COAST. WIND
ADVISORIES HOISTED FOR ZONE 28 AS WELL AS ZONES 23 AND 22. CLOSE
MONITORING NEEDED AS SECOND WRAP APPROACHES THE COAST IN ZONES
23 AND 22 LATE TONIGHT AND WILL BE IN A MORE FAVORABLE
ORIENTATION FOR MAX ADVISORY LEVEL GUSTS. STORM LEVEL WINDS FOR
ALL OUTSIDE AND OFF SHORE MARINE ZONES. SEA STATE ALSO A CONCERN
WITH 30 FT SEAS MOVING INTO THE SOUTHERN OFF SHORE AND OUTSIDE
WATERS TONIGHT.

 QPF LIMITED TO AROUND ONE QUARTER OF AN INCH FOR MOST LOCATIONS
WITH EASTERLY TO SOUTHEASTERLY FLOW FROM SFC TO 700 MB. UPPER
LEVEL SUPPORT ALREADY OUT RUNNING SURFACE LOW AT THIS POINT. THE
LOW IS AT MAX DEPTH NOW OR WILL BE IN THE NEXT COUPLE OF HOURS
AND IS EXPECTED TO SLOWLY WEAKEN AS IT MOVES NORTHWEST THROUGH
THE GULF SATURDAY. PRECIP TYPE IS EXPECTED TO BE RAIN ACROSS THE
PANHANDLE WITH THE EXCEPTION OF HAINES AND SKAGWAY WHERE PRECIP
MAY START OUT AS SNOW. MINOR ACCUMULATIONS POSSIBLE NORTH OF
HAINES BEFORE PRECIP TRANSITIONS TO RAIN.

 GFS REMAINS THE MODEL OF CHOICE AS ITS INITIALIZATION WAS VERY
GOOD AND RUN TO TUN CONTINUITY REMAINS SOLID. GFS STORM TRACK AND
STRENGTH REMAIN A MIDDLE OF THE ROAD SOLUTION AND WAS BLENDED
WITH INHERITED GRIDS FOR THE SHORT TERM.

.LONG TERM...BIGGEST CONCERN IN LONGER RANGE IS RIGHT AT THE
START. STORM WILL BE TRACKING NW THRU THE CENTRAL GULF SUN WITH A
SECOND WRAP OF OCCLUDED FRONT AFFECTING AT LEAST PART OF SE AK SUN
INTO SUN NIGHT. MAIN ISSUE WILL BE HOW STRONG WINDS WILL BE WITH
THIS FEATURE. THERE IS A GOOD CHANCE OF ADVY LEVEL WINDS OVER MUCH
OF THE AREA AS THE SECOND WRAP MOVES THRU...BUT AT THIS POINT ONLY
KEPT ANY ADVYS GOING INTO THE LONGER TERM THAT STARTED IN THE
SHORT TERM...AND DID NOT ISSUE ANY POTENTIAL ADVYS THAT WOULD
START SUN. THERE IS A CHANCE THAT WINDS COULD HIT WARNING LEVELS
ALONG THE CENTRAL COAST AROUND MIDDAY SUN...BUT AT THIS POINT WILL
KEEP AN ADVY GOING FOR THEM. LATER SHIFTS CAN UPGRADE IF WARNING
LEVEL WINDS LOOK LIKELY.

 AFTER THAT STORM MOVES OUT...MODELS IN GOOD AGREEMENT WITH NEXT
SYSTEM MOVING IN TUE...BUT DIVERGE SOMEWHAT THEREAFTER. AFTER
COORDINATION WITH WFO PAFC...WENT WITH 00Z GFS THRU TUE DAY
PERIOD...BLENDED GFS WITH HPC FOR TUE NIGHT...THEN WENT WITH HPC
FOR WED ON OUT. MAIN THING IS RIDGE WILL BUILD OVER THE AREA LATE
IN THE WEEK AND WILL LIKELY STEER SYSTEMS FURTHER W WITH
TIME...AND BY FRI...AREA SHOULD BE DRY UNDER THE UPPER RIDGE.
THERE IS POTENTIAL FOR A MULTI-DAY FOG SCENARIO STARTING BY NEXT
WEEKEND BUT THIS WILL DEPEND ON EXACTLY WHERE UPPER RIDGE SETS UP
AND HOW MUCH LOW LEVEL FLOW THERE IS.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...HIGH WIND WARNING UNTIL 6 PM AKST THIS EVENING FOR AKZ027.
         WIND ADVISORY FROM NOON TODAY TO 4 PM AKST SUNDAY FOR AKZ022.
         WIND ADVISORY FROM 9 AM THIS MORNING TO 4 PM AKST SUNDAY FOR
     AKZ023.
         WIND ADVISORY UNTIL 9 PM AKST THIS EVENING FOR AKZ018.
         WIND ADVISORY UNTIL 9 AM AKST SUNDAY FOR AKZ028.
MARINE...STORM WARNING FOR PKZ041>043-051-052.
         GALE WARNING FOR PKZ012-013-021-022-031>036.
         SMALL CRAFT ADVISORY FOR PKZ011.

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CCC/RWT