Area Forecast Discussion
Issued by NWS Eureka, CA

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000
FXUS66 KEKA 311106
AFDEKA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
406 AM PDT FRI OCT 31 2014

.SYNOPSIS...A COLD FRONT IS MOVING ACROSS THE REGION THIS MORNING
BRINGING RAIN. BEHIND THE FRONT THERE WILL BE A BREAK IN THE RAIN
BEFORE SHOWERS AND A SLIGHT CHANCE OF THUNDERSTORMS MOVE INTO THE
AREA THIS AFTERNOON AND TONIGHT. SHOWERS WILL TAPER OFF SATURDAY
AS HIGH PRESSURE BUILDS INTO THE AREA FOR A FEW DAYS.

&&

.SHORT TERM...A COLD FRONT MOVING ONSHORE THIS MORNING IS BRINGING
PERIODS OF HEAVY RAIN. WINDS ARE IN THE 10 TO 20 MPH AT THE
SURFACE SO THE RAINFALL AMOUNTS ARE MORE CONSISTENT OVER THE AREA
THAN WITH STRONGER WINDS AND UPSLOPE/DOWNSLOPE EFFECTS. IR SAT
SHOWS THE BACK EDGE OF THE CLOUDS ASSOCIATED WITH THE FRONT ABOUT
50 MILES OFFSHORE. MODELS ARE INDICATING A DRY SLOT WILL MOVE ONTO
THE COAST AROUND SUNRISE NORTH OF CAPE MENDOCINO AND SLOWLY SPREAD
SOUTH AND EAST THROUGH THE MORNING.. THERE WILL LIKELY BE A
FAIRLY DECENT BREAK IN THE RAIN ASSOCIATED WITH THIS DRY SLOT.

THE HRRR MODEL IS INDICATING SOME SHOWERS THIS AFTERNOON...BUT
THE NAM AND GFS ARE NOT SHOWING MUCH INSTABILITY OR QPF SO THE
SHOWERS MAY BE WEAKER THAN PREVIOUSLY THOUGHT. LEFT THE SLIGHT
CHANCE OF THUNDERSTORMS AND SMALL HAIL IN THE FORECAST FOR THIS
AFTERNOON AND EVENING AS THE IR SAT SHOWING THE TROUGH OFFSHORE
HAS FAIRLY COLD CLOUD TOPS. AROUND -45C IN THE STRONGEST SHOWERS
TO THE WEST OF US. SNOW LEVELS WITH THESE SHOWERS WILL DROP AS LOW
AS 4500 FT TONIGHT AND THIS MAY BRING A FEW INCHES OF SNOW.

TONIGHT AND SATURDAY SHOWERS WILL REMAIN SCATTERED OVER THE AREA.
THERE MAY BE SOME PERIODS OF HEAVIER SHOWERS AS SOME VORT MAXES
ROTATE AROUND THE BOTTOM OF THE TROUGH. AT THIS POINT IT IS
DIFFICULT TO PINPOINT THE TIMING OF THESE SHORTWAVES. THERE DOES
APPEAR TO BE A BIT OF VORT MAX ON THE BACKSIDE OF THE TROUGH AS IT
MOVES THROUGH SATURDAY AFTERNOON. THIS COULD ENHANCE SHOWERS A
BIT...ALTHOUGH ONLY ECMWF HAS SOME QPF DURING THIS TIME.

SATURDAY NIGHT INTO SUNDAY A RIDGE OF HIGH PRESSURE STARTS TO
BUILD INTO THE AREA WHICH WILL PUT AN END TO THE SHOWERS. THIS
WILL LIKELY ALLOW FOG AND LOW CLOUDS TO DEVELOP OVER THE INLAND
VALLEYS DUE TO THE RECENT RAINS. ANY AREAS THAT MANAGE TO REMAIN
CLEAR WILL LIKELY SEE SOME FROST. HIGHS ACROSS THE AREA WILL
LIKELY REBOUND INTO THE 60S IN MOST AREAS WITH COOLER TEMPERATURES
AT HIGHER ELEVATIONS. THE INLAND VALLEYS MAY BE A BIT SLOW TO
CLEAR OUT AND THIS COULD KEEP TEMPERATURES A BIT COOLER THERE.
SUNDAY NIGHT INTO MONDAY MORNING APPEARS TO HAVE A BETTER CHANCE
FOR FROST...HOWEVER ONCE AGAIN THERE MAY BE QUITE A BIT OF LOW
LEVEL MOISTURE AROUND. THIS WILL NEED TO BE WATCHED AS IT GETS
CLOSER. MONDAY MODELS ARE SHOWING A WARM FRONT MOVING ACROSS THE
AREA AND BRINGING SOME CLOUDS. THIS WILL ALSO INHIBIT COOLING IN
THE NORTHERN AREAS. FOR NOW ANY RAINFALL LOOKS TO BE CONFINED TO
DEL NORTE COUNTY AS THE FRONT STALLS OUT...BUT CONFIDENCE IS LOW
ON THE EXACT LOCATION WHERE THE FRONT STALLS OUT. MKK

&&

.AVIATION...MODERATE RAIN ASSOCIATED WITH THE COLD FRONT MOVING
THROUGH IS CONTINUING ACROSS MUCH OF THE AREA BRINGING MVFR TO IFR
CONDITIONS. THIS WILL TAPER OFF FROM NORTHWEST TO SOUTHEAST THIS
MORNING. LATE THIS MORNING INTO THE AFTERNOON SHOWERS WILL START
TO DEVELOP ACROSS THE AREA. THERE ARE STILL SOME QUESTIONS ON THE
STRENGTH AND COVERAGE OF THESE SHOWERS...BUT IT LOOKS LIKE THERE
IS A SLIGHT CHANCE FOR THUNDER THIS AFTERNOON AND EVENING. MAINLY
VFR CONDITIONS ARE EXPECTED THIS AFTERNOON WITH LOCAL IFR
CONDITIONS IN THE HEAVIER SHOWERS. SHOWERS WILL CONTINUE
OVERNIGHT...BUT ARE EXPECTED TO WEAKEN AND THE THREAT FOR THUNDER
WILL DIMINISH. MKK

.LONG TERM...PER THE PREVIOUS DISCUSSION, KEPT THE LONG TERM
FORECAST MOSTLY UNCHANGED WITH MINIMAL NUDGES IN THE POP GRIDS,
MAINLY TO MATCH OUR NEIGHBORS. OTHERWISE, POPULATED WITH THE
CONSMODEL FOR MOST OF THE GRIDS.

&&

.MARINE...THE MORNING BUOY OBSERVATIONS SHOW A MODERATE TO FRESH
BREEZE WITH WAVE HEIGHTS RANGING FROM 4-5 FT. THE 0415Z ASCAT PASS
SHOWED AN AREA OF STRONGER WINDS JUST AHEAD OF THE COLD FRONT.
CONSIDERING THE EASTWARD MOVEMENT OF THE FRONT, THIS MATCHES WELL
WITH WHAT THE BUOYS ARE CURRENTLY REPORTING. THE GUSTY WINDS WILL
CONTINUE EARLY THIS MORNING AS THE COLD FRONT CROSSES OUR WATERS.
WINDS WILL SHIFT TO THE NORTHWEST BY TONIGHT AS THE FRONT MOVES
INLAND, THEN REMAIN LIGHT TO MODERATE THROUGH THE WEEKEND. THE
STRONGEST WINDS ARE EXPECTED TO BE SOUTH OF CAPE MENDOCINO WHERE THE
SURFACE PRESSURE GRADIENT WILL BE STRONGER. AS FOR SEAS, THEY WILL
BUILD TODAY AS A POST-FRONTAL SWELL ENTERS THE WATERS. LEFT THE
SC.Y`S UNCHANGED. SEAS ARE EXPECTED TO SUBSIDE ON SUNDAY THEN BUILD
AGAIN EARLY NEXT WEEK AS ANOTHER SWELL MOVES THROUGH THE WATERS.

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...
     SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 9 PM PDT
     SATURDAY FOR PZZ450-470.

     SMALL CRAFT ADVISORY FROM 3 PM PDT THIS AFTERNOON TO 2 AM PST
     SUNDAY FOR PZZ455-475.

&&

$$

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