Area Forecast Discussion
Issued by NWS Eureka, CA

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000
FXUS66 KEKA 301124
AFDEKA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
424 AM PDT SAT MAY 30 2015

.SYNOPSIS...WARM AND DRY WEATHER WILL CONTINUE ACROSS THE
INTERIOR TODAY AS A HIGH PRESSURE RIDGE PERSISTS ACROSS THE AREA.
A WEAK COLD FRONT WILL APPROACH THE AREA SUNDAY AND MONDAY
PRODUCING COOLER TEMPERATURES INLAND AND SOME LIGHT SHOWERS. LATE
IN THE WEEK HIGH PRESSURE WILL RETURN.

&&

.DISCUSSION...HIGH PRESSURE REMAINS IN PLACE OVER THE WEST COAST
THIS MORNING...ALTHOUGH IT HAS STARTED TO PUSH OFF TO THE EAST AS
THE UPPER LEVEL TROUGH AND ASSOCIATED WEAK COLD FRONT START TO
APPROACH THE AREA. A FEW HIGH CLOUDS HAVE STARTED TO MOVE IN OVER
THE AREA THIS MORNING AND LOW CLOUDS PERSIST AT THE COAST. INLAND
TEMPERATURES WILL LIKELY BE A COUPLE DEGREES COOLER THAN
YESTERDAY AS HEIGHTS START TO FALL AND THERE IS SOME HIGH LEVEL
CLOUDS. ALONG THE COAST A FEW BREAKS ARE POSSIBLE THIS AFTERNOON
AS THE APPROACHING SYSTEM MAY INCREASE THE MIXING AND COULD BREAK
UP THE MARINE LAYER A BIT.

TONIGHT HIGH AND MID LEVEL CLOUDS WILL CONTINUE TO THICKEN UP AS
THE TROUGH APPROACHES...BUT NO RAIN IS EXPECTED UNTIL SUNDAY
AFTERNOON. THERE IS STILL THE POTENTIAL FOR A FEW THUNDERSTORMS
SUNDAY AFTERNOON AND EVENING IN TRINITY AND EASTERN DEL NORTE
COUNTIES. THE COAST MAY REMAIN DRY SUNDAY AFTERNOON WITH SHOWERS
ONLY OVER THE INLAND AREAS. THE TROUGH IS NEGATIVELY TILTED AND
THERE IS SOME SHEAR SO LEFT THE THUNDERSTORMS IN THE FORECAST.
SURFACE CAPE ON THE GFS IS MINIMAL BY 06Z...BUT MU CAPE IS OVER
500 J/KG IN NORTHERN TRINITY COUNTY SO A FEW EVENING THUNDERSTORMS
ARE POSSIBLE. SPC HAS A MARGINAL RISK FOR SEVERE THUNDERSTORMS IN
THUNDERSTORMS WHERE THERE IS MUCH BETTER INSTABILITY...IF THE
STRENGTH OR TIMING CHANGES A BIT THIS COULD MOVE SOUTH AND WILL
NEED TO BE WATCHED.

LATE SUNDAY NIGHT INTO MONDAY ANOTHER SHORTWAVE MOVES THROUGH.
THIS LOOKS MORE LIKELY TO BRING SOME RAIN TO MOST AREAS NORTH OF
CAPE MENDOCINO...ALTHOUGH AMOUNTS WILL LIKELY BE LESS THAN A
QUARTER INCH. TEMPERATURE PROFILES LOOK QUITE STABLE SO THE
THUNDERSTORM THREAT LOOKS MINIMAL. MONDAY NIGHT THE BEST CHANCE
FOR RAIN IS OVER...HOWEVER ZONAL FLOW WILL LIKELY KEEP THE CLOUDS
AROUND AND THERE MAY BE A FEW SHOWERS OR SPRINKLES IN THE INLAND
AREAS. TUESDAY SKIES WILL START TO CLEAR AND THERE MAY BE A FEW
LINGERING SHOWERS OVER THE INTERIOR. WEDNESDAY THE ECMWF HAS
STARTED TO BRING ANOTHER UPPER LEVEL LOW DOWN OVER THE WEST COAST.
THE GFS HAS A MUCH WEAKER SHORTWAVE REMAINING NORTH OF THE AREA.
IF THE ECMWF SOLUTION PANS OUT THERE WOULD LIKELY BE SOME SHOWERS
OR THUNDERSTORMS OVER THE INLAND AREA. THIS IS THE FIRST I HAVE
SEEN THIS SOLUTION SO LEFT THE FORECAST DRY. THIS WILL NEED TO BE
WATCHED.

THURSDAY INTO THE WEEKEND HIGH PRESSURE LOOKS TO BUILD BACK INTO
THE AREA. OFFSHORE FLOW LOOKS TO SET UP...SO THE COAST MAY FINALLY
SEE SOME CLEARING AT LEAST IN THE AFTERNOON. INLAND TEMPERATURES
WILL WARM BACK UP TO AROUND 90. MKK

&&

.AVIATION...SATELLITE IMAGERY THIS MORNING SHOWS HIGH CLOUDS OVER
NORTHWEST CALIFORNIA, BLOCKING THE VIEW OF THE LOWER STRATUS CLOUDS.
COASTAL SITES ARE REPORTING BORDERLINE IFR/LIFR WHILE INLAND SITES
ARE VFR. THIS MEANS THE STRATUS REMAINS ALONG AT LEAST THE IMMEDIATE
COAST. ALONG THE COAST...EXPECT IFR CEILINGS TO PREVAIL TODAY DUE TO
WEAK ONSHORE WINDS. TEMPO VFR IS POSSIBLE LATE THIS AFTERNOON.
THOUGH, CONFIDENCE IN THIS OCCURRING IS LOW. INLAND...VFR WILL
PREVAIL.

&&

.MARINE...THE BUOYS THIS MORNING ARE REPORTING A NORTHERLY
MODERATE BREEZE AND MIXED SEAS RANGING FROM 4-5 FT. THE MORNING
ASCAT PASS JUST MISSED OUR WATERS. A WEAK PRESSURE GRADIENT ACROSS
OUR WATERS WILL ALLOW LIGHT WINDS AND LOW SEAS TO PREVAIL THROUGH
SUNDAY MORNING. WINDS WILL BECOME SOUTHERLY LATE SUNDAY INTO
MONDAY AS A WEAK DISTURBANCE APPROACHES AND THEN PASSES TO OUR
NORTH. RIGHT NOW NO HEADLINES ARE EXPECTED WITH THIS DISTURBANCE.
MODELS THEN REMAIN IN GOOD AGREEMENT SHOWING CONDITIONS
DETERIORATING TUESDAY ONWARD. STRENGTHENING HIGH PRESSURE OFFSHORE
WILL INTERACT WITH A THERMAL LOW DEVELOPING ACROSS INTERIOR
CALIFORNIA, CAUSING THE PRESSURE GRADIENT TO STRENGTHEN ACROSS OUR
WATERS. THIS WILL LEAD TO INCREASING NORTHERLY WINDS AND STEEP
SHORT PERIOD SEAS BEGINNING TUESDAY AND LASTING POSSIBLY THROUGH
THE END OF NEXT WEEK. IT`S STILL A LITTLE TOO EARLY TO DETERMINE
HOW STRONG THE WINDS WILL BE, BUT THE WORST CONDITIONS ARE
EXPECTED TO BE ACROSS THE OUTER WATERS.

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...NONE.
&&

$$

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