Gale Warning 360, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
257 PM AKST FRI NOV 13 2009

.SHORT TERM...VERY ACTIVE WEATHER PATTERN TODAY. A 978MB LOW
CONTINUES TO DEEPEN JUST SOUTH OF PWS AS ANOTHER 987MB LOW
DEEPENS FASTER JUST TO THE SOUTH OF KODIAK ISLAND. THE PAIR OF
LOWS CONTINUE TO DEEPEN AND MOVE NORTHEAST AND WILL COMBINE INTO
A 948 MB STORM FORCE LOW THIS EVENING. TRACK TAKES STORM ON SHORE
JUST WEST OF YAKUTAT AROUND 18Z TOMORROW.

HIGH WIND WARNINGS POSTED ALONG THE OUTER COAST FROM PAYA TO PAHY
AND FOR ZONES 28 AND 29 AS WELL. WRING LEVEL GUSTS EXPECTED TO
DEVELOP THIS EVENING ALONG THE NORTHERN COAST AND MOVE SOUTHWARD
OVERNIGHT. WIND ADVISORIES HOISTED FOR REST OF THE ZONES.

WSW HOISTED FOR THE NORTHERN PORTIONS OF THE HAINES HIGHWAY AND
ALONG THE KLONDIKE HIGHWAY ABOVE 500 FEET FOR THIS AFTERNOON
THROUGH TOMORROW MORNING FOR HEAVY SNOW. SNOW IS EXPECTED TO MIX
OUT LATE TONIGHT ALONG THE HAINES HIGHWAY BUT NOT BEFORE DUMPING 6
TO 8 INCHES OF SNOW. WHITE PASS SHOULD REMAIN SNOW ALL NIGHT AS
SNOW LEVEL RISES TO 1200 FEET. 6 TO 8 INCHES OF SNOW EXPECTED
THERE.

USED 12Z NAM12 FOR MINIMAL EDITS TO WIND...PRESSURE AND QPF
FIELDS. 12Z NAM12 INITIALIZED WELL AND IS DEPICTING THE PRESSURE
GRADIENT WELL. FORECAST CONFIDENCE IS ABOVE AVERAGE THROUGH THE
SHORT TERM.

.LONG TERM...STRONG AND LONG COLD ADJECTION WILL OCCCUR AFTER FROPA.

CONFIDENCE IS GOOD THAT A CHANGE FROM RAIN TO SNOW SHOWERS WILL
OCCUR IN A NW TO SE SEQUENCE SAT THROUGH SUN, ALBIET THE SHOWERS
SHOULD BE BOTH RAIN AND SNOW FOR ZONES 27 AND 28 ON SUN. THE MODEL
CONSENSUS INCLUDES THE 850 MB TEMPERATURE FIELD FOR SUN 00Z AMOUNG
THE UKMET, NAM, GFS, AND ECMWF. VALUES OF -8C REACH THE SRN PNHDL
HALF OF THE PNHDL ON ALL THESE MODELS AT 12Z SUN. THIS CONVECTION
WILL BE LARGELY DRIVEN BY THE CONVECTIVE AVAIALBLE POTENTIAL ENERGY
ASSOCIATED WITH THE COLD AMS OVER THE STILL WARM BNDRY LAYER, AND
THE MODIFICATION OF BOTH IS REASON THAT THE NEW ZONES MIX RAIN
BACK IN NORTH OF FREDERICK SOUND.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...WIND ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM AKST SATURDAY FOR
     AKZ026.
         HIGH WIND WARNING FROM 9 PM THIS EVENING TO 9 AM AKST SATURDAY
     FOR AKZ027-028.
         WIND ADVISORY UNTIL NOON AKST SATURDAY FOR AKZ024.
         WIND ADVISORY UNTIL 3 PM AKST SATURDAY FOR AKZ020-021-025.
         HIGH WIND WARNING FROM 9 PM THIS EVENING TO NOON AKST SATURDAY
     FOR AKZ022-023.
         HIGH WIND WARNING FROM MIDNIGHT TONIGHT TO 9 AM AKST SATURDAY
     FOR AKZ017-029.
         WIND ADVISORY UNTIL 9 PM AKST SATURDAY FOR AKZ019.
         WINTER STORM WARNING UNTIL MIDNIGHT AKST TONIGHT FOR AKZ019.
         WIND ADVISORY UNTIL MIDNIGHT AKST SATURDAY NIGHT FOR AKZ018.
         WINTER STORM WARNING UNTIL 9 AM AKST SATURDAY FOR AKZ018.
MARINE...STORM WARNING FOR PKZ012-022-036-041>043-051-052.
         GALE WARNING FOR PKZ011-013-021-031>035.

&&

CCC/JBT