FXUS66 KEKA 261250
AFDEKA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
450 AM PST THU NOV 26 2009

.SYNOPSIS...A COLD FRONT WILL APPROACH THE REGION LATER TODAY AND
TONIGHT...BRINGING RAIN TO THE REGION. SHOWERS WILL CONTINUE INTO
FRIDAY AS THE SYSTEM HEADS INLAND. PRECIPITATION WILL END FRIDAY
NIGHT WITH DRY BUT BREEZY WEATHER EXPECTED FOR THE WEEKEND AS HIGH
PRESSURE BUILDS OVER THE AREA.

&&

.DISCUSSION...HAPPY THANKSGIVING! SURFACE LOW PRESSURE CONTINUES TO 
DEEPEN ABOUT 400 NM WNW OF EUREKA AT PRESS TIME WITH JUST SOME HIGH 
LEVEL CLOUDS STREAMING ACROSS THE DISTRICT. ADDITIONALLY...LOW 
STRATUS HAS FILLED IN ALONG THE COAST. THE SURFACE LOW WILL PUSH 
EAST TODAY AND REACH THE CENTRAL OREGON COAST BY EVENING WITH THE 
ATTENDANT COLD FRONT JUST OFFSHORE THE NORTHERN CAL COAST BY THAT 
TIME. RAIN WILL BE A NON-EVENT UNTIL THIS AFTERNOON AT THE 
EARLIEST...WITH THE THREAT CONFINED TO COASTAL HUMBOLDT UP INTO DEL 
NORTE COUNTY. RAIN WILL OVERSPREAD THE ENTIRE FORECAST AREA 
OVERNIGHT...WITH PRECIPITATION REACHING THE UKIAH AREA BY AROUND 
MIDNIGHT. PRECIPITATION AMOUNTS STILL LOOK QUITE MODEST FOR A LATE 
NOVEMBER SYSTEM...WITH UP TO AN INCH IN DEL NORTE COUNTY DWINDLING 
TO A TENTH OF AN INCH OR TWO IN SOUTHERN MENDOCINO AND EASTERN 
TRINITY COUNTIES. BOTH SATELLITE AND THE LATEST NUMERICAL MODELS 
SUGGEST A MORE SOUTHERLY TRAJECTORY WITH THE UPPER LOW...CUTTING 
ACROSS MENDOCINO COUNTY AND DROPPING IT SOUTHWARD INTO THE SAN 
JOAQUIN VALLEY FRIDAY NIGHT. THUS POPS/QPF WERE ADJUSTED HIGHER FOR 
MENDOCINO COUNTY AND WE ALSO KEPT THE SHOWERS GOING THROUGH THE DAY 
FRIDAY. FARTHER NORTH...SHOWERS SHOULD GRADUALLY DIMINISH DURING THE 
DAY BUT THE COLD CORE LOOKS SUFFICIENTLY STRONG THAT SOME SHOWERS 
WILL PROBABLY STILL LINGER OVER THE HILLS. ROBUST NORTHERLY FLOW 
WILL DRY OUT THE AIRMASS RAPIDLY FRIDAY NIGHT AND A DRY BUT BREEZY 
WEEKEND CAN BE EXPECTED. WE HAVE LEFT THE EXTENDED FORECAST THROUGH 
WEDNESDAY DRY...BUT THERE IS SOME SUGGESTION OF A WEAK SYSTEM 
UNDERCUTTING THE RIDGE BY THE MIDDLE OF NEXT WEEK ALTHOUGH 
CONFIDENCE IN ITS STRENGTH AND TRACK IS LACKING AT THIS POINT. 
BURGER 

&&

.AVIATION...SATELLITE IMAGERY SHOWS A LARGE AREA OF CLOUDS MOVING 
OVER NORTHWEST CALIFORNIA THIS MORNING. CONDITIONS VARY WIDELY 
ACROSS THE AREA AS OF 12Z...FROM LIFR AT ACV TO IFR AT CEC TO VFR AT 
UKI. AS A FRONT APPROACHES THE REGION...THE VISIBILITIES WILL 
IMPROVE AND THE CEILINGS WILL LIFT. EXPECT MVFR FOR THE COASTAL 
AIRSTRIPS TODAY AND VFR FOR THE INLAND AIRSTRIPS. RAIN IS EXPECTED TO 
OVERSPREAD THE AREA FROM NORTHWEST TO SOUTHEAST LATE THIS AFTERNOON 
INTO THIS EVENING. STROZ

&&

.MARINE...SOMEWHAT TRICKY MARINE FORECAST THIS MORNING. TO START, 
BUOYS ARE SHOWING THE LONG PERIOD WEST SWELL NEAR 12 FT AT 17 
SECONDS MOVING THROUGH THE WATERS. THIS SWELL WILL PEAK NEAR 15 FT 
THIS MORNING. THEREFORE, SCA FOR HAZARDOUS SEAS REMAIN UP FOR ALL 
THE WATERS. A FRONT WILL MOVE ACROSS THE WATERS LATE TONIGHT. MODELS 
HAVE REALLY BACKED OFF ON THE SOUTH WINDS AHEAD OF THE FRONT, BUT 
STILL CAN'T RULE OUT A FEW GALE FORCE GUSTS TO 35 KT TONIGHT AS THE 
FRONT MOVES THROUGH AND THE WINDS VEER TO THE NORTHWEST BEHIND THE 
FRONT. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT AND SET UP A 
FAIRLY STRONG PRESSURE GRADIENT OVER THE OUTER WATERS. ALL THE 
MODELS HAVE COME INTO GREAT AGREEMENT REALLY RAMPING THE WINDS UP. 
THEREFORE, ISSUED GALE AND HAZARDOUS SEAS WARNINGS OVER THE SOUTHERN 
OUTER WATERS FROM LATE TONIGHT THROUGH LATE SATURDAY NIGHT. GUSTS 
COULD APPROACH 45 KT FRIDAY EVENING AND WIND WAVES COULD APPROACH 12 
FT. HAVE ALSO ISSUED A GALE AND HAZARDOUS SEAS WATCH OVER THE 
NORTHERN OUTER WATERS FROM LATE TONIGHT THROUGH LATE FRIDAY NIGHT. 
THERE IS A LOT OF UNCERTAINTY REGARDING THE WIND STRENGTH AND 
COVERAGE AND THE ASSOCIATED WAVES, SO THE DAY CREW WILL HAVE TO TAKE 
A CLOSER LOOK AT THIS. AT THE SAME TIME, A NORTHWEST SWELL WILL 
CONTINUE TO MOVE THROUGH THE WATERS. THE WINDS WILL BEGIN TO EASE 
AND THE SEAS SUBSIDE OVER THE WEEKEND AS THE PRESSURE GRADIENT 
WEAKENS. STROZ

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 11 PM PST MONDAY FOR PZZ450-455.

     GALE WATCH FROM LATE TONIGHT THROUGH LATE FRIDAY NIGHT FOR 
     PZZ470.

     SMALL CRAFT ADVISORY UNTIL 3 AM PST FRIDAY FOR PZZ470-475.

     HAZARDOUS SEAS WATCH FROM LATE TONIGHT THROUGH LATE FRIDAY NIGHT 
     FOR PZZ470.

     GALE WARNING FROM 3 AM FRIDAY TO 3 AM PST SUNDAY FOR PZZ475.

     HAZARDOUS SEAS WARNING FROM 3 AM FRIDAY TO 3 AM PST SUNDAY FOR 
     PZZ475.

&&

$$

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