FXUS66 KEKA 222152
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
152 PM PST TUE DEC 22 2009
.SYNOPSIS...ANY LINGERING SHOWERS WILL DISSIPATE EARLY THIS EVENING
AS HIGH PRESSURE MOVES INTO THE AREA. GENERALLY FAIR WEATHER WILL
PREVAIL OVER THE NEXT FEW DAYS WITH PATCHY VALLEY FOG POSSIBLE
OVERNIGHT AND INTO THE EARLY MORNING HOURS. THE NEXT SYSTEM WILL
ENTER THE REGION EARLY IN THE WEEKEND.
&&
.DISCUSSION...AN UPPER LEVEL LOW OVER NE CAL WILL CONTINUE TO SINK
TO THE SE OVERNIGHT. THE ASSOCIATED TROF THAT HAS PASSED THROUGH
THE AREA WILL FOLLOW THIS FEATURE. THIS WILL CLEAR THE WAY FOR
HIGH PRES TO SLIDE INTO POSITION OVER THE W COAST. HIGH PRES WILL
SETTLE IN BY WED AND REMAIN IN PLACE THRU FRI MORN. MODELS
CONTINUE TO REMAIN CONSISTANT WITH THIS SOLN. WHAT WILL NEED TO BE
WATCHED IS THE DEPARTURE TIME OF THE RIDGE. MODEL SPREAD IN
REAGRDS TO THE INCOMING SYSTEM FOR THE WEEKEND HAS BEEN SLIMMING
BUT REMAINS LARGE ENOUGH THAT CONFDC IS LOW TO MDT FOR TIMING.
THIS NEXT SYSTEM COULD MOVE OUT THE RIDGE A TOUCH FASTER THAN
FORECASTED...BUT WILL WAIT FOR MORE MODEL AGREEMENT BEFORE
ALTERING THE TIMING. THE CHIEF CHANGE TO THE FORECAST IS THE INTRO
OF POP/CHC RAIN TO SRN MENDO COUNTY SAT MORN AS THE SYSTEM
APPROACHES. OTHERWISE THERE ARE NO SIG CHANGES TO THE ONGOING
FORECAST. BFG
&&
.AVIATION...HIGH PRESSURE BUILDING INTO THE INTERIOR TONIGHT WILL
PRODUCE OFFSHORE WIND FLOW AND BRING AN END TO THE RAIN ACTIVITY.
LINGERING LOW LEVEL MOIST AIR WILL CREATE IDEAL CONDITIONS FOR FOG
AND LOW CLOUD DEVELOPMENT IN THE VALLEYS TONIGHT. THE COASTAL TAF
SITES SHOULD ONLY EXPERIENCE SHALLOW GROUND FOG AND MIST. THE FOG
AND LOW CLOUDS SHOULD MIX OUT MOST EVERYWHERE DURING THE DAY ON
WEDNESDAY. DJB
&&
.MARINE...SEAS WERE QUITE ROUGH TODAY...15 FEET WITH A DOMINANT
PERIOD OF 12 SECONDS. THIS IS ON THE HAZARDOUS SEAS WARNING SIDE
(RED) FOR SEAS BASED ON TOTAL WAVE HEIGHTS AND DOMINANT WAVE
PERIODS. LOOKING AT THE SWAN DECOMPOSITION OF THE SEA STATE REVEALS
TWO DISTINCT SWELL GROUPS...ONE CENTERED NEAR 10 SECONDS AND ANOTHER
NEAR 15 SECONDS FROM NEARLY THE SAME DIRECTION. 20-30 KTS OF WIND
WAVE CHOP ON-TOP OF THE 2 SWELL GROUPS HAS RESULTED IN A CHAOTIC
AND CONFUSED SEA STATE FORECAST. THERE IS GOOD NEWS...HOWEVER.
WINDS SHOULD DECREASE NEAR SHORE TONIGHT AS HIGH PRESSURE BUILDS
INLAND. IN ADDITION...THE SHORT-PERIOD SWELL SHOULD SUBSIDE
TONIGHT...WHILE THE LONG PERIOD SWELL GROWS SLIGHTLY. SEA HEIGHTS
WILL REMAIN MODERATELY LOW THU THROUGH FRI AND THEN RAMP UP ON SAT.
MODELS CONTINUE TO SHOW A NEW CENTRAL PACIFIC STORM DEVELOPING WED
THROUGH THU. WAVE FIELDS FROM THE ENP AND SWAN SEEM REASONABLE BASED
ON THE POSITION...DURATION AND INTENSITY OF THE STORM. THUS FOR NOW
WILL CONTINUE TO FORECAST SWELL BUILDING TO 16-18 FT SATURDAY
AFTERNOON AND EVENING. DJB
&&
.EKA WATCHES/WARNINGS...SMALL CRAFT ADVISORY UNTIL 2 AM PST
WEDNESDAY FOR PZZ450-455. SMALL CRAFT ADVISORY UNTIL 10 PM PST
WEDNESDAY FOR PZZ470-475.
&&
$$
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