Hazardous Seas Warning 46, NWS Eureka, CA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
159 PM PST TUE FEB 9 2010

.SYNOPSIS...WEAK HIGH PRESSURE WILL BUILD OVER THE NORTH STATE
TONIGHT BRINGING DRY WEATHER WITH PATCHY VALLEY FOG. A WEAK FRONT
WILL APPROACH THE REGION LATE TOMORROW...POSSIBLY BRINGING A FEW
SPRINKLES OR LIGHT SHOWERS. A SERIES OF SYSTEMS WILL IMPACT THE
REGION THROUGH THE END OF THE WEEK.

&&

.DISCUSSION...THE MAIN FORECAST CHALLENGES ARE PRECIPITATION
CHANCES/AMOUNTS LATE WEDNESDAY THROUGH THE END OF THE WEEK.

VERTICALLY STACKED LOW PRESSURE CURRENTLY WEST OF THE MONTEREY/SLO
COUNTY COAST WILL CONTINUE TO MOVE AWAY FROM THE AREA OVERNIGHT
LEAVING DRY WEATHER AND (MAINLY) CLEAR SKIES. VALLEY FOG WILL
DEVELOP OVERNIGHT AND SOME HIGH CLOUDS IN ADVANCE OF THE NEXT SYSTEM
WILL GRADUALLY SPILL INTO THE AREA FROM THE WEST. WHILE SOME PATCHY
FROST CANNOT BE RULED OUT ALONG THE COAST...MOST PLACES WILL SETTLE
IN THE UPPER 30S SO IT WILL NOT BE A WIDESPREAD/SEVERE ISSUE.

A WARM FRONTAL SYSTEM WILL BRING INCREASING MID AND HIGH LEVEL
CLOUDINESS TO THE REGION DURING THE DAY WEDNESDAY. SPRINKLES OR
LIGHT SHOWERS MAY DEVELOP DURING THE AFTERNOON ALONG THE COAST NORTH
OF THE CAPE...BUT THESE SHOULDN'T BE MUCH. WEDNESDAY NIGHT WILL OFFER
UP A BETTER THREAT FOR RAIN BUT EVEN THEN AMOUNTS WILL PROBABLY BE
A TENTH OF AN INCH OR LESS FOR MOST AREAS. SOME TIMING DIFFERENCES
PERSIST BETWEEN COMPETING MODELS...BUT THERE IS SOME INDICATION
THAT WE MAY HAVE A SIZABLE BREAK IN PRECIP BETWEEN LATE WEDNESDAY
NIGHT AND THURSDAY AFTERNOON WHEN THE COLD FRONT APPROACHES. OPTED
NOT TO MONKEY AROUND WITH THE INHERITED FORECAST'S POPS GIVEN
THESE DIFFERENCES BUT THIS MAY NEED TO BE BETTER REFINED GIVEN THE
POTENTIAL 12-18 HOUR WINDOW OF LITTLE OR NO RAIN. ANOTHER SOMEWHAT
STRONGER FRONT WILL AFFECT US ON FRIDAY.

THE PATTERN TRANSITION IS A LITTLE MORE AMBIGUOUS THEREAFTER. THE 5
WAVE SHOWS THE COLD CORE LOW OVER THE RUSSIAN FAR EAST RETREATING
WEST INTO SIBERIA...WHICH MAY ALLOW RIDGING TO DEVELOP ACROSS THE WEST
FOR MUCH OF NEXT WEEK. RIGHT NOW...WE HAVE TAKEN A MIDDLE OF THE
ROAD APPROACH WHICH ESSENTIALLY SUPPORTS THE THREAT OF WEAK
SYSTEMS BRUSHING UP AGAINST THIS RIDGE WITH PERIODIC CHANCES (AT
OR BELOW CLIMATOLOGY) FOR RAIN BUT NO MAJOR STORMS. BURGER

&&

.AVIATION...HIGH CLOUDS WILL MOVE ACROSS THE REGION TONIGHT AS
WEAK HIGH PRESSURE MOVES OVER THE REGION. THE HIGH CLOUDS WILL BE
SLOWER TO REACH MENDOCINO COUNTY...WITH CLEAR SKIES PREVAILING MOST
THE NIGHT. PATCHY FOG MAY DEVELOP IN INTERIOR VALLEYS
OVERNIGHT...ESPECIALLY ACROSS MENDOCINO COUNTY WHERE CLEARING AND
LINGERING SURFACE MOISTURE WILL BE MORE ABUNDANT. TH

&&

.MARINE...MAIN MARINE IMPACTS THIS WEEK ARE INCREASING WINDS AND
SWELL LATE IN THE WEEK. MODELS ARE FAIRLY CONSISTENT THAT SOUTH
WINDS WILL DEVELOP WED AFTERNOON AS WEAK FRONT APPROACHES NW CA. THE
SURFACE PRESSURE GRADIENT WILL TIGHTEN AS THE FRONT CLIPS THE
NORTHERN WATERS WED NIGHT...AND TIGHTEN EVEN MORE THU MORNING WHEN A
STRONGER FRONT WILL NEAR THE WATERS. THE DIFFERENT MODELS VARY ON
THE POSITION AND STRENGTH OF THE LOW ASSOCIATED WITH THIS
FRONT...BUT ALL SUGGEST THE POTENTIAL FOR GALES THU...ESPECIALLY
NORTH OF CAPE MENDOCINO. CONFIDENCE IS HIGHER FOR GALES ACROSS THE
NORTHERN OUTER WATERS...WHERE A GALE WATCH HAS BEEN ISSUED. THESE
STORMS WILL ALSO GENERATE A LARGE LONG PERIOD NW SWELL LATE THU
NIGHT AND FRI..HAVE GONE A COUPLE OF FEET BELOW GUIDANCE DUE TO THE
VARIABILITY OF MODELS ON THE LOW. TH

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.

NORTHWEST CALIFORNIA COASTAL WATERS...GALE WATCH FROM THURSDAY
MORNING THROUGH THURSDAY EVENING PZZ470.

&&

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