Gale Warning 233, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
1208 PM AKDT TUE SEP 30 2008

.SHORT TERM...THE LATEST SATELLITE IMAGERY SHOWS THE WARM
FRONT/BAROCLINIC ZONE OVER THE EASTERN GULF AND MOVING OVER THE
PAYA AREA. THERE IS A WAVE RIDING NORTH OUT OF THE NORTH PACIFIC
ALONG THE BAROCLINIC ZONE THIS MORNING. THE NORTHERN PANHANDLE IS
SEEING SOME SPOTTY RAIN BUT SOUTH OF JUNEAU THERE IS PARTLY
CLOUDY SKIES. THERE IS SOME WINDY CONDITIONS OVER THE PAGY AREA
AND MIN GALES OVER NORTHERN LYNN CANAL.

THERE IS A UPPER TROF OVER THE WESTERN GULF THIS MORNING AS
INDICATED ON WV. THIS TROF WILL DRIFT EASTWARD THROUGH WED AND
PUSH THE UPPER RIDGE OVER THE PANHANDLE EAST OF THE AREA AND
INCREASE PVA OVER THE PANHANDLE. AS THE TROF DRIFT EAST IT WILL
SEND THE WAVE MOVING NORTH THIS MORNING OVER THE FAIRWEATHERS AND
PUSH THE BAROCLINIC ZONE BACK OVER THE NORTHERN INNER CHANNELS TO
HAVE RAIN DEVELOPING OVERNIGHT. SOME OF THIS RAIN WILL BE HEAVY AT
TIMES AND WITH ABOUT 1 INCH OF RAIN EXPECTED RIVER OVER THE
NORTHERN AREAS WILL RISE AGAIN BUT WILL REMAIN IN THEIR BANKS. THE
SOUTHERN AREAS WILL REMAIN TO BE MAINLY DRY BUT THE CENTRAL INNER
CHANNELS WILL SEE A CHANCE TO LIKELY POPS LATE TONIGHT AS THE
ONSHORE FLOW INCREASES.

AS THE UPPER TROF DRIFTS EAST THROUGH WED ANOTHER WAVE WILL FORM
ALONG THE FRONT AND MOVE INTO THE EASTERN GULF. THIS WAVE WILL
PUSH RAIN ACROSS THE ENTIRE PANHANDLE WITH THE EXCEPTION OF THE
HYDER AREA. THE BAROCLINIC ZONE WILL HAVE MOVES EAST OF PAYA THEY
TOO WILL REMAIN ON THE DRY SIDE ON WED.

AS FOR WINDS...THE STRONG WINDS NEAR PAGY SHOULD SLOWLY DIMINISH
THROUGH THE AFTERNOON. THE EASTERN GULF WILL SEE WINDS INCREASE
THROUGH TONIGHT FROM THE SOUTH WITH 25KT OVER THE FAR SE GULF TO
15KT NEAR CROSS SOUND. ALL OF THESE WINDS WILL CONTINUE TO
INCREASE INTO WED AS THE NEXT WAVE MOVES NORTH.

.LONG TERM...LARGE UNCERTAINTY CONTINUES IN THE LONG TERM AS
MODEL SOLUTIONS DIVERGE SIGNIFICANTLY BY 00Z FRIDAY WITH A MUCH
STRONGER LOW IN THE 00Z/12Z ECMWF MOVING INTO THE EASTERN GULF.
ATTM...WEAKER 12Z GFS SOLUTION WAS PREFERRED DUE TO BETTER
INITIALIZATION OF JET STREAM ENERGY AND MID LEVEL MOISTURE ACROSS
THE NORTHERN PACIFIC. AFTER CONSIDERABLE DISCUSSION WITH AFC AND
HPC A PREFERRED 00Z ECMWF ENSEMBLE SOLUTION WAS REACHED FOR THE WEEKEND
THROUGH EARLY NEXT WEEK. BOTH THE 00Z ECMWF ENSEMBLE SOLUTION AND
THE 12Z GFS 5-WAVE 500 MB PATTERN KEEP THE MEAN LONG WAVE TROUGH
IN THE GULF THROUGH THE WEEKEND INTO EARLY NEXT WEEK WHICH WILL
KEEP MOIST SOUTHWESTERLY ONSHORE FLOW ACROSS THE PANHANDLE. KEPT GRIDS
AS IS FOR THE MOST PART WITH A 50-50 BLEND TOWARD THE NEW HPC
FORECAST WITH LOW PRESSURE REMAINING IN THE GULF DAYS 4 THROUGH 8.

WITH THE SIGNIFICANT TIMING DIFFERENCES FOR THE INDIVIDUAL SURFACE
LOWS AND FRONTAL BANDS THIS WEEKEND INTO EARLY NEXT WEEK KEPT WIND
PATTERN RATHER GENERAL WITH POPS ABOVE NORMAL. THE CENTRAL AND
SOUTHERN PANHANDLE WILL CONTINUE TO SEE MODERATE TO HEAVY RAINFALL
EACH DAY THROUGH FRIDAY AFTER WHICH THE FRONTAL BAND AND MID
LEVEL VORTICITY PATTERN BECOME MUCH LESS ORGANIZED. BY EARLY NEXT
WEEK COLDER TEMPERATURES COULD ADVECT INTO THE PANHANDLE AS COLDER
AIR FROM NORTHERN ALASKA ROTATES AROUND THE UPPER LEVEL LOW AND
INTO THE PANHANDLE WITH 850 MB TEMPS IN THE -2 TO -3 C RANGE.
FORECAST CONFIDENCE REMAINS LOW AS SIGNIFICANT MODEL DIFFERENCES
CONTINUE IN THE LONG TERM AND EMERGE EVEN AS EARLY AS THURSDAY
AFTERNOON.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ012.
         SMALL CRAFT ADVISORY FOR PKZ033-035-036-041>043-051-052.

&&

ABJ/PSS