Area Forecast Discussion
Issued by NWS Eureka, CA

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FXUS66 KEKA 262259
AFDEKA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
259 PM PST MON JAN 26 2015

.SYNOPSIS...WEAK LOW PRESSURE TO OUR SOUTH WILL BRING A SLIGHT
CHANCE OF LIGHT RAIN SHOWERS TO THE INTERIOR ON TUESDAY. DRY
CONDITIONS ARE EXPECTED WEDNESDAY INTO THE WEEKEND AS A RIDGE
MOVES OVER NORTHERN CALIFORNIA.

&&

.DISCUSSION...THE ONGOING FORECAST REMAINS ON TRACK. THE RIDGE OF
HIGH PRESSURE IS SHIFTING EASTWARD. CLOUD COVER IS INCREASING AS
A WEAK TROUGH APPROACHES THE PACIFIC NORTHWEST. THIS WEAK TROUGH
IN CONJUNCTION WITH A CUT OFF LOW JUST OFF OF SOUTHERN CALIFORNIA
COULD BRING A FEW SPRINKLES OR A LIGHT RAIN SHOWER TO THE EASTERN
REACHES OF THE FORECAST AREA ON TUESDAY. THE MODELS CONTINUE TO
BE IN GOOD AGREEMENT SHOWING RAINFALL AMOUNTS WILL BE MINIMAL, IF
ANY. THIS IS BECAUSE THERE IS VERY LITTLE MOISTURE WITH BOTH THE
LOW AND THE TROUGH. SO EXPECT MOSTLY CLOUDS ON TUESDAY. DRY
CONDITIONS WILL RETURN WEDNESDAY AND CONTINUE INTO THE WEEKEND AS
A RIDGE MOVES BACK OVER NORTHERN CALIFORNIA. BY EARLY NEXT WEEK
THE MODELS ARE HINTING AT THE RIDGE WEAKENING AND MOVING EASTWARD
AS A TROUGH DEVELOPS OFFSHORE. THIS PATTERN CHANGE WOULD BRING US
COOLER TEMPERATURES AND WETTER CONDITIONS. GIVEN THE UNCERTAINTYTHAT
FAR OUT, KEPT POPS NEAR CLIMO FOR DAYS 6 AND 7 AND WENT WITH THE
CONSMODEL FOR THE REMAINDER OF THE GRIDS.

&&

.AVIATION...LOW CLOUDS/FOG HAVE PLAGUED COASTAL SITES NORTH OF
FORT BRAGG TODAY WITH HIGH CLOUDS MOVING OVERHEAD ASSOCIATED WITH
AN UPPER LEVEL SYSTEM UNDERCUTTING THE UPPER RIDGE. KACV HAS
RANGED FROM AIRFIELD MINIMUMS TO VFR. THINK THAT THE MID TO HIGH
LEVEL CLOUDS ASSOCIATED WITH THE UPPER LEVEL SYSTEM WILL BE ENOUGH
TO MITIGATE SOME OF THE INTERIOR VALLEY LOW CLOUDS/FOG FORMATION
LATER TONIGHT. ALONG THE COAST...THERE MAY BE A FEW HOURS THIS
EVENING WHERE THE COASTAL SITES IMPROVE TO VFR...BUT
OVERALL...EXPECT STRATUS TO HANG AROUND THROUGH THE NIGHT
PRODUCING MVFR TO IFR CIGS AND VSBYS. STP

&&

.MARINE...WITH THE PRESSURE GRADIENT REMAINING RELATIVELY WEAK
WINDS HAVE SWITCHED TO SOUTHERLY OVER THE AREA...ALTHOUGH THEY
REMAIN LIGHT...5 TO 10 KT. TONIGHT A WEAK DISTURBANCE UNDERCUTTING
THE RIDGE WILL WEAKEN THE PRESSURE GRADIENT FURTHER BRINGING LIGHT
AND VARIABLE WINDS. TUESDAY AS THE DISTURBANCE MOVES OVER THE AREA
SOUTHERLY WINDS INCREASE TO 15 KT ONCE AGAIN. WEDNESDAY A WEAK
DISTURBANCE MOVES BY TO THE NORTH. THIS WILL BRING A RETURN TO
NORTHERLY WINDS WEDNESDAY NIGHT. THESE WILL INCREASE ON THURSDAY
AND FRIDAY AS HIGH PRESSURE BUILDS BACK INTO THE PACIFIC
NORTHWEST. A SMALL CRAFT ADVISORY FOR WINDS MAY BE NEEDED IN THE
OUTER WATERS DURING THE PEAK OF THESE NORTHERLY WINDS. FLOW WILL
BE NORTHEASTERLY NEAR THE COAST WHICH WILL LIMIT HOW MUCH THE
SHORT PERIOD WIND DRIVEN WAVES CAN BUILD. LATE SUNDAY OR EARLY
MONDAY WINDS LOOK TO BECOME SOUTHERLY ONCE AGAIN.

THERE IS ALSO A LONG PERIOD WAVE MOVING THROUGH THE WATERS.
CURRENTLY IT HAS DROPPED TO AROUND 7 FT AT 14 SECONDS. THIS SWELL
WILL DIMINISH TONIGHT AND CONTINUING TO DIMINISH ON TUESDAY AND
WEDNESDAY.

LATE WEDNESDAY MODELS REMAIN ON TRACK...BRINGING IN ANOTHER LONG
PERIOD SWELL. INITIALLY IT WILL BE AROUND 2 FT AT 20 TO 21
SECONDS...BUT WILL BUILD TO 4 FT AT 18 SECONDS BY THURSDAY
MORNING. THIS MAY POSE A SNEAKER WAVE THREAT TO THE AREA ON
THURSDAY. MKN

&&

.EKA WATCHES/WARNINGS/ADVISORIES...

CA...NONE.

NORTHWEST CALIFORNIA COASTAL WATERS...NONE.

&&

$$

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