Small Craft Advisory 474, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
242 PM AKDT FRI AUG 19 2011

.SHORT TERM...980 MB LOW NEAR KODIAK WILL SEND A STRONG AND VERY
MOIST OCCLUDED FRONT INTO THE NORTHWEST POTION OF THE PANHANDLE
LATE TONIGHT THEN SLOWLY MOVING ACROSS SOUTHEAST ALASKA
SATURDAY...AND EXITING THE SOUTHEAST PORTION LATE SATURDAY NIGHT.
A WAVE ALONG THE TRAILING FRONT MOVES NE ACROSS SOUTH CENTRAL
SOUTHEAST ALASKA SATURDAY AFTERNOON AND EVENING.

 GALE FORCE BARRIER ENHANCED WINDS OVER THE NORTHERN GULF
DIMINISH THIS EVENING BUT GALE FORCE WINDS DEVELOP OVER THE
SOUTHERN COASTAL WATERS IN ADVANCE OF STRENGTHENING FRONT LATER
TONIGHT THAT SPREAD ACROSS SOUTHERN INNER CHANNELS ON SATURDAY.
SMCR WINDS FOR REMAINDER OF INNER CHANNELS SOUTH OF PAJN-CSP
LINE. LIGHT NORTH WINDS IN LYNN CANAL/GLACIER BAY TURN SOUTHERLY
SATURDAY AFTERNOON. WIND ADVISORY EXPECTED FOR PUBLIC ZONES SOUTH
OF SUMNER ST SAT.

 A LONG FETCH AND VERY MOIST 1.5 TO 1.7 PRECIPITABLE WATER
ASSOCIATED WITH A 100+ KT JET STREAM/140KT JET CORE THAT
TERMINATES ACROSS SOUTHEAST ALASKA ON SATURDAY. RAINFALL RATES
ARE EXPECTED TO APPROACH 1 INCH IN 6 HRS OVER MUCH OF THE
PANHANDLE FOR 12 TO 18 HRS AND COULD EXCEED 2 INCHES IN 6 HRS FOR
WETTEST CENTRAL AND SOUTHERN LOCATION. AN AREAL FLOOD ADVISORY
WILL BE ISSUED FOR ALL SOUTHEAST ALASKA XCP PAYA ZONE.

 USED NAM EARLY ON BLENDING TO THE 12Z ECMWF BY SATURDAY
AFTERNOON.

.LONG TERM...MAINLY FOCUSED ON THE 00Z SUN TO 00Z MON PERIOD FOR
THIS FORECAST ISSUANCE DUE TO HYDRO AND WIND HAZARDS. ENDED UP
USING THE 12Z ECMWF FOR THAT PERIOD AS IT WAS HANDLING THE KEY
SHORTWAVE THAT WILL TRIGGER SFC LOW PRES WAVE DEVELOPMENT ALONG
THE FRONT THE BEST. HOWEVER THE MODELS HAVE STRUGGLED WITH THIS
DEVELOPMENT AS THEY HAVE NOT BEEN VERY CONSISTENT WITH IT. SO
CONFIDENCE IN TIMING THE ENDING OF SPECIFIC HAZARDS IS NOT HIGH AT
THIS POINT. LEFT FORECAST AFTER 00Z MON AS IS.

BY 00Z SUN...HEAVY RAIN SHOULD BE FALLING GENERALLY SE OF A
PAJN-PASI LINE. EXPECT THIS HEAVY RAIN TO SHIFT SLOWLY EWD THROUGH
SAT NIGHT AS FRONT MOVES INLAND...AND THE HEAVY RAIN SHOULD BE
OUT OF THE SRN AREA BY DAYBREAK SUN. WINDS SHOULD DROP OFF A BIT
BEFORE THAT TIME FRAME SO THE WIND ADVY WILL BE ENDING SOONER THAN
THE FLOOD ADVY FOR THE SRN AREAS.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...AREAL FLOOD ADVISORY FROM NOON SATURDAY TO 6 AM AKDT SUNDAY FOR
     AKZ026>029.
         WIND ADVISORY FROM 10 AM TO 10 PM AKDT SATURDAY FOR AKZ026.
         WIND ADVISORY FROM 12 AM SATURDAY TO MIDNIGHT AKDT SATURDAY NIGHT
     FOR AKZ027-028.
         AREAL FLOOD ADVISORY FROM 4 AM TO 4 PM AKDT SATURDAY FOR
     AKZ018>025.
MARINE...GALE WARNING FOR PKZ033-035-036-041>043-051-052.
         SMALL CRAFT ADVISORY FOR PKZ021-022-031-032-034-053.

&&

MM/RWT