Hazardous Seas Warning 12, NWS Eureka, CA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
451 AM PDT SAT MAR 28 2009

.SYNOPSIS...HIGH PRESSURE OVER THE EASTERN PACIFIC WILL BRING
ANOTHER DRY AND WARM DAY TO NORTHWEST CALIFORNIA TODAY. A COLD FRONT
WILL PASS OVER THE AREA TONIGHT BRINGING LIGHT RAIN TO AREAS NORTH
OF CAPE MENDOCINO. HIGH PRESSURE WILL RETURN ON SUNDAY WITH CLEAR
SKIES AND GUSTY WINDS.

&&

.SHORT TERM...TODAY THROUGH TUESDAY...HIGH PRESSURE IS IN PLACE OVER
THE EASTERN PACIFIC WHICH WILL IMPOSE ANOTHER DRY AND WARM DAY ON NW
CA. A WEAK S/WV WILL MOVE INTO WA/OR LATER THIS AFTERNOON DRAGGING
WITH IT A WEAK COLD FRONT THAT WILL PASS OVER THE AREA TONIGHT.
NOTHING SIG EXPECTED WITH THIS SYSTEM...JUST SOME LIGHT RAIN NORTH
OF THE CAPE INTO EARLY SUNDAY MORNING. RAIN TOTALS SHOULD BE LESS
THAN 0.2 INCHES ACROSS THE AREA. EXPECT GUSTY NORTH WINDS COME LATE
SUNDAY MORNING/AFTERNOON AS THE GRADIENT TIGHTENS BEHIND THE FRONT.
NAM IS SUGGESTING SUSTAINED WINDS OF NEAR 20 KT WHILE GFS IS LOOKING
FOR SUSTAINED WINDS OF 20-25KT. WIND SPEEDS OF THIS MAGNITUDE SHOULD
BE SUFFICIENT TO MIX OUT ANY SFC MOISTURE BEHIND THE FRONT AND
MINIMIZE MARINE LAYER INFLUENCE AFTER FROPA. SUNDAY NIGHT SHOULD
STILL SEE PATCHY FOG ALONG THE COAST AND IN INLAND VALLEYS DUE TO
CLEAR SKIES AND EFFICIENT RADIATIONAL COOLING. MONDAY LOOKS TO BE
REAL NICE ACROSS THE AREA WITH CLEAR SKIES AND A CHANCE FOR SOME
GUSTY WINDS ALONG THE COAST. THE BIG QUESTION IS WHEN WILL THE
STRATUS RETURN TO THE NORTH COAST. SUSTAINED NORTHERLY FLOW SHOULD
HELP THE MARINE LAYER SET BACK BACK UP BY MONDAY NIGHT AND WOULD
EXPECT STRATUS JUST OFFSHORE AS EARLY AS SUNRISE TUESDAY. GUSTY
WINDS CAN BE EXPECTED TUESDAY AFTERNOON ALONG THE COAST. BK

.LONG TERM...TUESDAY NIGHT THROUGH FRIDAY...MEDIUM RANGE MODELS ARE
SHOWING RELATIVELY GOOD CONSISTENCY IN THE INITIAL PART OF THE LONG
TERM...WITH WEAK RIDGING OVER THE EASTERN PACIFIC AND WNW FLOW
ACROSS THE WEST COAST. THIS SCENARIO CONTINUES THROUGH AROUND 12 UTC
THURSDAY...AT WHICH TIME A PASSING SHORTWAVE WILL PRODUCE A CHANCE
OF RAIN OVER THE NORTHERN CWA. AFTER 00 UTC FRIDAY THE MODEL
SOLUTIONS BEGIN TO DIVERGE RATHER DRASTICALLY...WITH THE OPERATIONAL
GFS FORMING A RIDGE IN THE PACIFIC NORTHWEST AND THE ECMWF TAKING
THE OPPOSITE POSITION WITH A TROUGH IN THE SAME LOCATION. STEPPING
OUT THROUGH TIME IT APPEARS THAT THE MODELS ARE OUT OF PHASE WITH
EACH OTHER...WITH THE GFS ABOUT 6-12 HRS AHEAD. CILIBERTI

&&

.AVIATION...A COLD FRONT WILL PASS OVER NW CA TONIGHT WITH THE FRONT
PASSING OVER KCEC/KACV BETWEEN 00Z AND 02Z...AND COMPLETELY THRU THE
AREA BY 06Z. LIGHT RAIN CAN BE EXPECTED NORTH OF CAPE MENDOCINO AS
THE FRONT PASSES WITH LITTLE TO NO RAIN ELSEWHERE. WINDS WILL BECOME
QUITE GUSTY BEHIND THE FRONT WITH COASTAL LOCATIONS LIKELY GUSTING
IN EXCESS OF 20 KTS THROUGH THE END OF THE PERIOD. COASTAL STRATUS
WILL REMAIN A CHALLENGE. LOOKS LIKE THE COASTAL AIRFIELDS WILL HAVE
A TOUGH TIME SHAKING THE IFR CIGS UNTIL AFTER FROPA. ITS POSSIBLE
THE CIG WILL SCATTER EARLY THIS AFTERNOON FOR A FEW HOURS HOWEVER
CONFIDENCE IS NOT HIGH AND HAVE LEFT THE CIGS DOWN ACCORDINGLY. BK

&&

.MARINE...NORTH WINDS CONTINUE OVER THE WATERS TODAY...STRONGEST IN
THE OUTER WATERS SOUTH OF THE CAPE. THE MODERATE SPEEDS TODAY WILL
INCREASE TONIGHT...WITH GALES EXPECTED BY SUNDAY IN THE S OUTER
WATERS AND OCCASIONAL GALE FORCE GUSTS ELSEWHERE. THE PERIOD OF
STRONG WINDS WILL CONTINUE THROUGH MONDAY AND POSSIBLY INTO
TUESDAY...AND MODELS HAVE RAMPED THINGS UP SOMEWHAT...SO EXPECT THAT
A HAZARDOUS SEAS WARNING MAY NEED TO BE ISSUED FOR THE S WATERS.
MEANWHILE...A LONG PERIOD NW SWELL MOVED INTO THE WATERS OVERNIGHT.
THE BUOYS ARE SHOWING MIXED PERIODS OF 16 SECONDS AND 7
SECONDS...RESULTING FROM THE MIX OF WIND DRIVEN WAVES AND SWELL.

NOTE...BUOY 22 HAS GONE ADRIFT AND IS CURRENTLY MOVING TO THE
SOUTHWEST AT AROUND 1 KT. EARLY THIS MORNING IT WAS ABOUT 6 NM SOUTH
OF ITS NORMAL POSITION. AS IT CONTINUES TO DRIFT...ITS POSITION
WILL BE REPORTED ON THE NATIONAL DATA BUOY CENTER WEB PAGE. IT IS
STILL REPORTING DATA AND WILL LIKELY CONTINUE TO DO SO UNTIL IT IS
RECOVERED. CILIBERTI

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
GALE WARNING CAPE MENDOCINO TO PT ARENA 10 TO 60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS PT ST GEORGE TO CAPE
MENDOCINO OUT 60 NM.
SMALL CRAFT ADVISORY CAPE MENDOCINO TO PT ARENA OUT 10 NM.

&&

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