Hazardous Seas Warning 14, NWS Eureka, CA

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE EUREKA CA
445 AM PDT SUN APR 12 2009

.SYNOPSIS...A COLD FRONT WILL BRING A CHANCE OF LIGHT RAIN NORTH OF
CAPE MENDOCINO TODAY WITH A BETTER CHANCE OF RAIN TONIGHT. A FEW
LINGERING SHOWERS WILL CONTINUE INTO TUESDAY WITH DRIER WEATHER
EXPECTED FOR THE END OF THE WEEK.

&&

.DISCUSSION...A COLD FRONT ABOUT 450 MILES WEST OF NW CALIFORNIA
WILL MOVE EASTWARD TODAY TOWARD THE AREA.  AN AREA OF WEAK
ISENTROPIC LIFT OUT AHEAD OF THE FRONT WILL PROVIDE A CHANCE OF RAIN
NORTH OF CAPE MENDOCINO LATER THIS MORNING INTO THIS AFTERNOON.
RAIN WILL INCREASE THIS EVENING AND TONIGHT AS THE FRONT APPROACHES
THE COAST.  RAIN WILL QUICKLY TAPER OFF MONDAY BEHIND THE FRONT FOR
MOST AREAS...WITH A FEW SHOWERS LINGERING NORTH OF CAPE MENDOCINO.

A COLD UPPER LOW WILL DIVE THROUGH THE PAC NW INTO THE GREAT BASIN
ON TUESDAY.  MODEL AGREEMENT IS VERY GOOD REGARDING THIS FEATURE
NOW.  THE LOW WILL CONTINUE THE POSSIBILITY OF SHOWERS FOR NORTHERN
AREAS THROUGH THE DAY TUESDAY.  AS THE WESTERN EDGE OF THE LOW CLIPS
THE NW CORNER OF THE STATE...SNOW LEVELS IN THE SHOWERS WILL LOWER
CONSIDERABLY ON TUESDAY.  H7 TEMPS ARE FORECAST TO REACH AT LEAST AS
LOW AS -14C IN THE EURO AND -16C IN THE GFS AND NAM...WHICH WOULD
SUPPORT SNOW LEVELS BELOW 2000 FEET OVER THE FAR NORTH.  HOWEVER...
GIVEN THE CONTINUING SLIGHT MODEL DIFFERENCES...WILL KEEP SNOW
LEVELS AROUND 2000 FEET FOR TUESDAY RATHER THAN GOING MUCH LOWER.
IN ANY EVENT...LIMITED MOISTURE (PWATS AROUND 0.25 INCHES) WILL KEEP
QPF LOW IN ANY SNOW SHOWERS THAT FALL BEHIND THE FRONT.

THE COLD AIR WILL ALSO BRING THE POTENTIAL FOR FROST/FREEZE ISSUES
TUE AND WED MORNINGS.  TUE MORNING WILL BE THE WARMER OF THE TWO
DAYS SINCE THE COLDEST AIR WILL NOT HAVE QUITE SETTLED IN OVER THE
REGION YET...AND AS NORTH WINDS REMAIN BREEZY OVERNIGHT.  WED
MORNING WILL SEE LIGHT WINDS AND CLEARER SKIES...AND ATTM IT APPEARS
FREEZING TEMPERATURES WILL BE LIKELY ACROSS THE INTERIOR WITH TEMPS
BOTTOMING OUT IN THE UPPER 20S TO LOW 30S IN ZONES 3 AND 76.

MODELS ARE CONSISTENT IN SHOWING RIDGING OVER THE WEST COAST
WEDNESDAY THROUGH NEXT WEEKEND...WITH A DRY FORECAST ALL THE WAY
THROUGH THE EXTENDED PERIODS. KL

&&

.AVIATION...CEILINGS HAVE LIFTED TO MVFR WITH VFR VSBYS IN NORTHERN
COASTAL AREAS BEHIND WEAK WARM FRONT. RUC13 SHOWS SLIGHT ISENTROPIC
LIFT AT OR BORDER ABOUT SUNRISE SO SHOULD SEE FEW AREAS OF IFR
CIGS/VSBY. WILL SEE MORE WIDESPREAD IFR CIGS/VSBY BY LATE AFTERNOON
ESPECIALLY NORTH OF GARBERVILLE AS COLD FRONT APPROACHES WITH -RA.
FRONTAL PASSAGE EXPECTED ABOUT MIDNIGHT NEAR KCEC AND WHATS LEFT OF
FRONT PASSED UKI ABOUT DAYBREAK ON MONDAY. LIGHT RAIN TURNING TO
SHOWERS BEHIND FRONT WITH CIGS LIFTING TO MVFR AND VFR VSBYS. DEAN

&&

.MARINE...LGT WINDS HAVE SHIFTED TO THE S ACROSS MOST OF THE WATERS
AS A WEAK FRONT APPROACHES. LONG PERIOD NW SWELL WILL PROPAGATE INTO
THE WATERS LATE TODAY. IT PASSED BUOY 46006 AT 1800 SAT AT 17
SECONDS AND HAD BUILT TO 13 FEET AT 15 SEC BY 0300 THIS MORNING.
USING SWELL DECAY TOOL IT WOULD ENTER OUR WATERS ABOUT 1600 THIS
AFTERNOON.  MODELS IN GOOD AGREEMENT ON NW SWELL PEAKING AT 11-12 FT
TUE BEFORE SUBSIDING. HAVE GONE AHEAD AND ISSUED THE SMALL CRAFT
ADVISORY FOR HAZARDOUS SEAS FOR ALL WATERS. IN ADDITION TO THE LONG
PERIOD SWELL...HIGH PRESSURE BUILDING INTO THE REGION WILL COMBINE
WITH A THERMAL TROUGH ALONG THE COAST TO PRODUCE INCREASED N WINDS
MON AND TUE. SOUTHERN OUTER WATERS LOOKS TO BE IN SOLID GALE
CRITERIA WITH GUSTS TO 35 TO 40 KT AND ISSUED GALE WATCH. HELD OFF
ON ISSUING FOR EITHER NORTHERN OUTER WATERS OR SOUTHERN INNER WATERS
AS THE AREAL EXTENT DOES NOT LOOK WIDESPREAD ENOUGH TO HOIST WATCH.
THESE AREAS WILL SEE LOCAL GALE GUSTS THOUGH MONDAY NIGHT INTO TUE.
DEAN.

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FOR ALL WATERS IN EFFECT
FROM 11 PM THIS EVENING TO 11 PM PDT TUESDAY.
GALE WATCH IN EFFECT FOR ZONE 475 FROM MONDAY AFTERNOON THROUGH LATE
TUESDAY NIGHT.

&&

VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA