Gale Warning 159, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
1151 AM ADT SUN MAY 11 2008

.SHORT TERM...THE LATEST SATELLITE IMAGERY SHOWS MOSTLY CLOUDY
SKIES OVER THE PANHANDLE WITH A FEW BREAK OF SUN. THERE ARE SOME
SCATTERED SHOWERS LINGERING AROUND THE AREA WITH A WEAKENING
UPPER TROF OVER THE AREA. THESE SHOWERS WILL DIMINISH THROUGH THE
EARLY EVENING AS THE UPPER AND MILD LEVEL DYNAMICS PASSES EAST
INTO CANADA. THE WINDS ARE RELATIVELY LESS THAN 20KT BUT THERE
WILL BE SOME HIGHER WIND SPEEDS NEAR STRONG SHOWERS.

 THERE IS A LOW SOUTH OF THE AK PENINSULA ATTM THAT WILL DRIFT NE
TONIGHT AND BE OVER THE BRISTOL BAY AREA BY MON AFTERNOON. THE
MODELS HAVE BEEN FAIRLY CONSTANT WITH THIS SYSTEM SO THERE IS
GOOD FORECASTER CONFIDENCE. THE 12Z GFS40 INITIALIZE FAIRLY WELL
WITH THE LOW CENTER AND TRACK OF THE ASSOCIATED WEATHER FRONT SO
WILL BASE TONIGHTS AND TOMORROWS FORECAST WITH THE GFS.

 THE WEATHER FRONT ASSOCIATED WITH THE LOW IN THE WESTERN GULF
WILL TRACK ACROSS THE GULF TONIGHT AND BE OVER THE EASTERN GULF
BY MORNING AND LIFT OVER THE PANHANDLE THROUGH THE AFTERNOON
HOURS. THE WINDS WILL INCREASE OVER THE OFFSHORE WATERS AND
EASTERN GULF TO GALES TONIGHT ALONG WITH A DEVELOPMENT A WEAK
BARRIER JET NEAR MARINE AREA 52. THE FRONT IS FAST MOVING SO THE
WINDS WILL DRASTICALLY DIMINISH FROM NORTH TO SOUTH BY THE
AFTERNOON BUT THERE WILL REMAIN SOME SMALL CRAFT WINDS OVER THE
SOUTHEAST GULF. THE SEAS WILL BUILD TO 17 FT BY MON AFTERNOON
OVER THE EASTERN GULF. FOR THE INSIDE WATERS...THE WINDS WILL BE
STRONGEST OVER EAST/WEST ORIENTED CHANNELS OVER THE NORTHERN HALF
WITH OTHER CHANNELS LESS THAN 20 KT. THE SOUTHERN HALF WILL SEE
THE STRONGEST WINDS WITH SMALL CRAFTS OVER THE CENTRAL INNER
CHANNELS AND MIN GALES OVER CLARENCE STRAIGHT. AS THE FRONT LIFTS
OVER THE AREA THESE WINDS WILL DIMINISH TO BELOW 25 KT.

 AS FOR THE LAND AREAS...STEADY RAIN WILL DEVELOP OVER THE
COASTAL AREAS LATE TONIGHT ALONG WITH INCREASES IN SUSTAINED
WINDS AND GUSTS. RAIN WILL MAY BE HEAVY AT TIMES OVER THE COASTAL
AREAS AND OVER THE FAR SOUTHERN AREAS AS THE STRONG FLOW ALOFT
WILL BE OUT OF THE SW AND ENHANCE OROGRAPHIC LIFT IN FAVORABLE
AREAS. RAIN WILL DEVELOP THROUGH THE MORNING HOURS OVER THE REST
OF THE PANHANDLE AS THE FRONT DRIFTS EAST AND PERSIST THROUGH THE
DAY. WILL ISSUE A WIND ADVISORY FOR ZONES 23-27 LATE TONIGHT
THROUGH MID MON AFTERNOON AND ZONE 28 EARLY MON MORNING INTO THE
EARLY EVENING HOURS. THE REASON FOR THIS IS THERE IS A VERY
STRONG (55KT) LOW LEVEL JET ASSOCIATED WITH THE FRONT ALONG WITH
A TIGHT PRESSURE GRADIENT AT THE SURFACE. THE REST OF THE
SOUTHERN HALF AND COASTAL AREAS WILL SEE BREEZY TO WINDY
CONDITIONS THROUGH THE DAY. THE NORTHERN HALF WILL SEE SOME GUSTY
WINDS AS THE FRONT LIFTS OVER THE AREAS BUT THINK IT WILL REMAIN
BELOW 25 MPH.

 &&

.LONG TERM...18Z WED A 965 MB LOW 400 NM S OF KODIAK WILL HAVE AN
OCLN WITH ARC ABT 200 NM S OF A YAKUTAT TO JUNEAU LN.  THIS SXN OF
THE OCLN WILL MOVE ONSHORE THE ERN GLFALSK BY 06Z. THE TRAILING
CDFNT WILL CONTINUE TO EXTEND SW FM DIXON ENTRANCE HWVR.  NMRS
WVS ON CDFNT WILL RESULT IN IT BCMG QSTNRY THRU DIXON ENTRANCE.
LARGE SCALE SW FLOW ASSOCD WITH AN ENHANCED POLAR FRONT ZONE WILL
PROVIDE PERIODIC HEAVY RAIN SPCLY TO THE SRN PNHDL WED AND THU.

MODELS...THE WED NIGHT TO THU LOW TRACKING N INTO THE GLFALSK HAS
BEEN GIVEN A NARROWER RANGE OF SOLUTIONS WITH THE 12Z RUN.
THE 12Z GFS WAS EASY FOR PAFC AND PAJN TO AGREE ON, ALBIET THE
ECMWF SOLUTION OF THE LOW ON A TRACK FARTHER TO THE FARTHER TO
THE EAST MIGHT STILL HAPPEN AND WE WILL HAVE TO WATCH FOR THIS.

ARCTIC AMS DVLPG OVR CHUKCHI SEA AND ADJACENT ARCTIC OCEAN
AND EXPANDING COVERAGE, AND WILL PROVIDE THE ENHANCED THERMAL
CONTRAST AND THEREFORE STRONGER POLAR FRONT ZONE POINTED TO
US FM THE SW BGNG WED.  LARGE SCALE PATN HAS LITTLE PROGRESSION
AND INCLUDES A DIGGING TROUGH, I.E. GAINING AMPLITUDE TOWARD
THE SOUTH, AND THIS WILL PROVIDE THE CONNECTION TO THE SUBTROPICS
THAT WILL HELP THE HEAVIER RAINFALL AS MENTIONED ABV.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ042-043-051-052.
         SMALL CRAFT ADVISORY FOR PKZ021-022-033>036-041.

&&

ABJ /