High Wind in Alaska, January 27 to 28, 2010

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
609 AM AKST WED JAN 27 2010

.SHORT TERM...SATELLITE IMAGERY THIS MORNING SHOWING 967 MB
STORM FORCE LOW 730 MI SOUTH OF PACD WITH SECONDARY CIRCULATION
MOVING OVER KODIAK AND LARGE DRY SLOT SHOWN IN WATER VAPOR
IMAGERY. HIGH PRESSURE OVER THE YUKON MOVING INTO N BRITISH
COLUMBIA. REMNANTS OF GULF LOW DISSIPATING NEAR PAYA WITH PRECIP
FROM FRONTAL REMNANTS DISSIPATING OVER THE N PANHANDLE. FRONTAL
BAND ASSOCIATED WITH THE STORM FORCE LOW MOVING INTO THE W GULF
WILL MOVE OVER THE PANHANDLE THIS AFTERNOON THROUGH TONIGHT.
PRECIPITATION ASSOCIATED WITH THIS FRONT WILL BE RAIN FREDERICK
SOUND SOUTH AND ALONG THE OUTSIDE COASTAL AREAS...A MIX OF SNOW
AND RAIN UP TO ICY STRAIT AND ALL SNOW NORTH. QPF VALUES A BIT
HIGHER WITH NEW MODEL RUNS BUT KEPT SNOW AMOUNTS ON THE 1 TO
3 INCH SIDE AS MIX OF RAIN MAY KEEP AMOUNTS DOWN. SOUTHEAST FLOW
A BIT MORE FAVORABLE FOR SNOW IN HAINES BUT KEPT SNOW AMOUNTS
BELOW ADV LVLS...WILL NEED TO KEEP AN EYE ON THIS.

 WINDS WILL BE THE MAIN ISSUE FOR THE SHORT TERM. STRONG 850 LLV
JET MOVING ALONG THE OUTER COAST WITH STORM FORCE WINDS IN
SOUTHERN MARINE ZONES. UPPER LVL GALE FOR THE REST OF THE OUTSIDE
WATER. ZONE52 NEARING STORM FORCE WITH BARRIER JET FORMATION AS
THE FRONT MOVES NORTH. START TIMES FOR WIND ADVY MAY BE A BIT
DELAYED BUT NOT ENOUGH TO DELAY START TIMES. ZONE27 WINDS GUST
WILL NEAR WARNING LEVELS BUT MAIN JET LOOKS TO STAY OFF SHORE
ENOUGH TO KEEP GUSTS JUST BELOW. SOUTHERN INSIDE WATERS WILL PICK
UP TO GALE FORCE WITH NORTHERN WATERS PICKING UP TO SMCR TO UPPER
SMCR. INCREASING E/W GRADIENT WILL PRODUCE OUT FLOW WINDS.

 MODELS WERE IN FAIR AGREEMENT TODAY WITH SOME VARIATION IN SPEED
OF SHORT WAVES AROUND THE MAIN LOW. USED A BLEND OF NAM12 WITH
INHERITED GRIDS. NAM SFC WINDS WERE A BIT LOW WITH BOUNDARY LAYER
NAM WINDS FOR THE OUTSIDE WATERS A BIT HIGH SO PICKED MIDDLE
GROUND. FORECAST CONFIDENCE IS AVERAGE WITH SOME QUESTIONS ON
SNOW AMOUNTS NEAR PAHN AND WINDS NEAR PAKW.

&&

.LONG TERM...FOCUS ON BEGINNING OF LONG TERM PERIOD WITH STORM
FORCE LOW MOVING NORTH INTO THE EAST CENTRAL GULF. STORM WARNINGS
DROP TO MAX GALES FOR OUTSIDE WATERS AND ALL OFF SHORE ZONES.
GALES ALSO ON TAP FOR CLARENCE STRAIT FREDERICK SOUND SUMNER
STRAIT NORTH AND SOUTH CHATHAM STRAITS ICY STRAIT AND CROSS SOUND.
SMALL CRAFT FOR THE REST OF THE INNER CHANNELS. WIND ADVISORIES
FOR PKZ 23 27 AND 28 AT TAIL END OF SHORT TERM MAY NEED TO BE
EXTENDED INTO EARLY LONG TERM PERIOD AS GRADIENT WILL REMAIN
STRONG.

 LIKELY POPS FOR MOST OF THE PANHANDLE WITH QPF AMOUNTS GENERALLY
LESS THAN ONE QUARTER OF AN INCH FOR THE TOMORROW AND TOMORROW
NIGHT PERIODS. THICKNESS VALUES SUPPORT ALL RAIN IN SOUTHERN
ZONES WITH A RAIN AND SNOW MIX THURSDAY NIGHT AND FRIDAY FROM
JUNEAU SOUTH TO FREDERICK SOUND. SNOW WITH OCCASIONAL MIX WITH
RAIN NEAR HAINES AND SKAGWAY. ALL SNOW FOR AREAS NORTH OF HAINES.
AREAS NORTH OF HAINES HAVE THE POTENTIAL FOR ADVISORY LEVEL SNOW
ACCUMULATIONS OR MORE IF ENOUGH QPF CAN BE FUNNELED INTO THE
REGION. AT THIS POINT AS THE FRONT SHEARS APART AS IT MOVES
INLAND THROUGH THE AREA AND WITH 850 AND 700MB FLOW FROM
SOUTHEAST VS SOUTH OR SOUTHWEST BELIEVE EASTERLY LOW LEVEL
COMPONENT WILL LIMIT QPF.

 SYSTEM SLOWLY WEAKENS IN THE GULF FRIDAY AND SATURDAY AS WEAK ON
SHORE FLOW CONTINUES ACROSS THE PANHANDLE THROUGH FRIDAY. A WEAK
LOW MOVES NORTH INTO THE EASTERN GULF SATURDAY AND SUNDAY WILL
PROVIDE LOW LEVEL OFF SHORE FLOW HOWEVER SIGNIFICANT DIFFERENCES
IN MODEL SOLUTIONS EXIST ON TRACK AND INTENSITY OF SMALLER SCALE
FEATURES BY THIS POINT. FORECAST CONFIDENCE IS AVERAGE THROUGH
THE WEEKEND AND THEN DECREASES TO BELOW AVERAGE PAST THAT POINT.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...WIND ADVISORY UNTIL 5 AM AKST THURSDAY FOR AKZ027.
         WIND ADVISORY FROM NOON TODAY TO 5 AM AKST THURSDAY FOR AKZ023-
     028.
MARINE...STORM WARNING FOR PKZ041-042.
         GALE WARNING FOR PKZ021-022-032>036-043-051-052.
         SMALL CRAFT ADVISORY FOR PKZ011>013-031.

&&

PRB/CCC