Gale Watch 7, NWS Seattle, WA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
920 AM PST FRI JAN 27 2012

.SYNOPSIS...HIGH PRESSURE WILL KEEP WESTERN WASHINGTON DRY THROUGH
SATURDAY. PATCHY FREEZING FOG WILL DEVELOP AGAIN TONIGHT AND
SATURDAY MORNING. HIGH PRESSURE WILL MOVE EAST OF THE CASCADES
SATURDAY NIGHT...AND A FRONTAL SYSTEM WILL MOVE INLAND FOR WET
WEATHER ON SUNDAY. RAIN AT TIMES CAN BE EXPECTED MONDAY THROUGH
WEDNESDAY.

&&

.SHORT TERM...AN UPPER RIDGE WILL PROVIDE DRY WEATHER TODAY. PATCHY
MORNING FOG WILL GIVE WAY TO MOSTLY SUNNY SKIES TODAY ALTHOUGH SOME
HIGH CLOUDS WILL BE MOVING THROUGH THE RIDGE AT TIMES.

A WARM FRONT WILL BRUSH THE NORTHERN PART OF THE FORECAST AREA LATE
TONIGHT AND SATURDAY. BOTH THE GFS AND NAM SHOW SOME SPOTTY
PRECIPITATION OVER THE NORTHERN PART OF THE AREA AND OVER THE
MOUNTAINS WITH THIS FEATURE. CLOUDS SHOULD BE ON THE INCREASE
ELSEWHERE SATURDAY.

SATURDAY NIGHT AND SUNDAY LOOK WET AS A FRONTAL SYSTEM MOVES
THROUGH. IT LOOKS LIKE THERE WILL BE A SHOT OF RAIN SATURDAY NIGHT
WITH THE FRONT THEN A SECOND BATCH OF RAIN SUNDAY AS A TRAILING
UPPER SHORT WAVE AND SECONDARY COLD FRONT MOVES THROUGH. THIS SYSTEM
WILL BRING SOME BREEZY TO LOCALLY WINDY CONDITIONS...ESPECIALLY
COAST AND NORTH INTERIOR. SNOW LEVELS WILL BE HIGH ENOUGH THAT SNOW
IN THE PASSES SHOULD NOT BE AN ISSUE BUT THE HIGHER VOLCANOES MAY
GET QUITE A BIT...ESPECIALLY MOUNT BAKER.  SCHNEIDER

.LONG TERM...PREVIOUS DISCUSSION...MODELS AGREE THAT THE PROGRESSIVE
ZONAL FLOW WILL CONTINUE THROUGH TUESDAY...WITH THE NEXT FRONTAL
SYSTEM MOVING THROUGH MONDAY NIGHT AND TUESDAY. THE GFS AND EUROPEAN
MODELS BOTH SHOW THE PATTERN BEGINNING TO AMPLIFY WEDNESDAY AND
THURSDAY...WITH A RATHER SHARP RIDGE BUILDING OVER THE PACIFIC
NORTHWEST COAST AND THEN SHIFTING INLAND. THE GFS IS FASTER WITH
THIS DEVELOPMENT...AND FOR BOTH MODELS THIS SOLUTION IS A DEPARTURE
FROM MOST PREVIOUS RUNS. A GENERALLY WET FORECAST STILL LOOKS
OKAY...BECAUSE IF THE RIDGE SOLUTION IS CORRECT IT WOULD STILL ALLOW
A WARM FRONT TO BRUSH THE AREA.   MCDONNAL

&&

.HYDROLOGY...THERE IS NO THREAT OF FLOODING FOR THE 7 DAYS. SCHNEIDER

&&

.AVIATION...MODERATE TO STRONG WNW FLOW ALOFT WILL CONTINUE THROUGH
TONIGHT. AN UPPER LEVEL RIDGE AXIS WILL PASS OVER WRN WA ON SAT. THE
AIR MASS WILL REMAIN DRY AND STABLE THROUGH THIS EVENING...THEN
MID-LEVEL MOISTURE WILL INCREASE EARLY SAT MORNING. SFC HIGH PRES
CENTER OVER WRN WA WILL WEAKEN TONIGHT. LIGHT AND VARIABLE SFC WINDS
WILL BECOME SLY AND OFFSHORE TONIGHT.

PATCHY FOG THIS MORNING OVER THE INTERIOR FROM THE SEATTLE METRO
AREA ON SOUTH THIS MORNING...THEN OUT THE CHEHALIS VALLEY TO KHQM.
FOG IS SHALLOW AND WILL BURN OFF QUICKLY SOON. OTHERWISE...VFR CONDS
THROUGH THIS EVENING AREAWIDE. SOME HIGH-BASED STRATO-CU CLOUDS ARND
040-060 ALONG AND NORTH OF A LINE FROM UIL-BLI SHOULD THIN OUT SOME
THIS AFTN.

KSEA...A LITTLE CONCERNED ABOUT THE FOG BANK WITHIN SIGHT SOUTHWEST
OF THE AIRFIELD AS OF 1710Z. ANY IMPACT FROM FOG ON THE AIRFIELD
SHOULD BE BRIEF...AS THE FOG IS SHALLOW AND IS EXPECTED TO QUICKLY
BURN OFF IN THE NEXT HOUR OR SO. OTHERWISE...LIGHT WINDS AND JUST A
FEW HIGH CLOUDS THROUGH THIS EVENING. A MID-LEVEL DECK MAY DROP
BELOW 050 AFT 15Z ON SAT MORNING.   HANER

&&

.MARINE...WINDS SHOULD REMAIN BELOW 20 KT ALL AREAS THROUGH SATURDAY
UNDER LIGHT NORTHERLY AND OFFSHORE GRADIENTS. WESTERLY SWELL OF
10-12 FEET WILL CONTINUE ON THE COAST UNTIL SOMETIME TONIGHT...SO
HAVE KEPT THE ADVISORY FOR HAZARDOUS SEAS GOING ALONG THE COASTAL
WATERS AND AT THE WEST ENTRANCE.

NEXT SYSTEM ARRIVES SATURDAY NIGHT...SATURDAY AFTERNOON IN THE
OFFSHORE WATERS. THIS LOOKS LIKELY TO BRING GALE FORCE SOUTHERLY
WINDS TO MOST WATERS. WILL BE CONSIDERING GALE WATCHES IN THE AFTN
FORECAST PACKAGE. COULD BE A SURGE OF WESTERLIES BEHIND THE FRONT
SUNDAY NIGHT OR MONDAY BUT GRADIENTS DO NOT LOOK STRONG NOW. SHORT
WAVE RIDGE BUILDS MONDAY FOLLOWED BY ANOTHER FRONT MONDAY NIGHT.
HANER/CHB

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS COAST AND WEST ENTRANCE.
     SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR.

YOU CAN SEE AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML.