782
FXUS66 KEKA 270815
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
115 AM PDT MON APR 27 2026
SYNOPSIS
A SLIGHT CHANCE FOR INTERIOR THUNDERSTORMS MONDAY LATE
AFTERNOON WITH PROBABILITIES EVEN LESS BEFORE SUNSET. CHILLY MORNING
TEMPERATURES ARE EXPECTED MONDAY MORNING FOR THE COLDEST INTERIOR
VALLEYS. DRIER WEATHER RETURNS MID NEXT WEEK.
DISCUSSION
THE MARINE LAYER GETS A BIT SHALLOWER OVERNIGHT INTO
MONDAY MORNING. WITH THE SATELLITE PRODUCTS SHOWING OBSERVABLE
STRATUS THINNING OUT FOR THE INTERIOR, TEMPERATURES COULD DIP TO
FROST THRESHOLDS WITH NO UPPER OR MID-LEVEL CLOUDS TO HINDER LONG
WAVE RADIATIVE COOLING. A FROST ADVISORY HAS BEEN HOISTED BUT IS
MARGINAL AS LOWS NEAR INTERIOR HUMBOLDT AND TRINITY WILL LIKELY
BOTTOM OUT AROUND 33-35F OVERNIGHT INTO MONDAY MORNING NEAR
DINSMORE, BLOCKSBURG, RUTH, MAD RIVER AND HAYFORK.
WITH AN UPPER LEVEL TROUGHING PATTERN PASSING SOUTH OF THE CWA, A
SLIGHT RISK OF THUNDERSTORMS FOR THE INTERIOR CONTINUES WITH LESS OF
A THREAT THAN SUNDAY WITH 13 - 15 PERCENT CHANCES FOR TRINITY AND
MENDOCINO COUNTIES. LESS OF A CHANCE FOR HUMBOLDT AND LAKE COUNTIES,
AROUND 10 PERCENT. EXPECT MOST CHANCES OF THUNDERSTORMS TO EASE
BEFORE SUNSET MONDAY.
HIGH PRESSURE LOOKS TO BE THE NEXT TREND AS BAROMETRIC PRESSURE AT
THE EKA WFO STATION IS STEADILY RISING OVERNIGHT. MODEL SOUNDINGS
SHOW DRYER AIR ALOFT WITH AN INVERSION, A PRELUDE TO SEASONAL
WARMING AND STABILITY IN THE VERTICAL PROFILE. DETERMINISTIC
ENSEMBLES ARE NOT IN AGREEMENT OVER THE NEXT PRECIPITATION EVENT FOR
THE FIRST WEEK OF MAY. STAY TUNED AS TIME DRAWS NEAR FOR
DEVELOPMENTS. /EYS
AVIATION
A VERY DEEP MARINE LAYER CONTINUES TO PERSIST ACROSS THE
AREA WITH 3KFT MVFR CEILINGS ALL ALONG THE COAST AND EVEN OVER MOST
OF THE INTERIOR. MVFR CONDITIONS WILL PERSIST INTO MONDAY MORNING
BEFORE GRADUALLY SCATTERING OFF THE VFR. THE TIMING OF SCATTERING,
HOWEVER, HAS HIGH UNCERTAINTY. INTERIOR AREAS WILL MOST LIKELY LIFT
AND SCATTER BEFORE 10 AM WHERE COASTAL LOCATIONS COULD REMAIN MVFR
WELL INTO THE AFTERNOON. THERE IS MORE UNCERTAINTY AS FOR CONDITIONS
MONDAY NIGHT INTO TUESDAY. WHILE CEILINGS WILL MOST LIKELY PERSIST,
PASSING LOW PRESSURE MAY BE ENOUGH TO LIFT THEM SO HIGH THAT
CONDITIONS COULD BE VFR DESPITE THE MARINE LAYER. AT THE VERY LEAST,
IFR CONDITIONS ARE VERY UNLIKELY (LESS THAN 10% CHANCE). /JHW
MARINE
GENTLE NORTH WINDS HAVE BUILT ACROSS ALL WATERS. SEAS HAVE
GENERALLY REMAINED MODERATE UP TO AROUND 7 FEET AT 14 SECONDS THANKS
TO A COMBINATION OF LINGERING SHORT PERIOD SEAS AND MODEST MID
PERIOD SWELL UP TO 4 FEET.
GENTLE WINDS WILL CONTINUE MONDAY WITH THE SWELL RAPIDLY DECAYING
THROUGH THE DAY. NORTHERLY WINDS WILL BEGIN TO RETURN TO SOUTHERN
WATERS MONDAY NIGHT AND SPREAD INTO THE NORTHERN WATERS BY TUESDAY.
STEEP SHORT PERIOD SEAS WILL BUILD IN RESPONSE AT LEAST IN THE OUTER
WATERS BY TUESDAY AFTERNOON. THOUGH STRONGEST IN THE OUTER WATERS,
SHORT PERIOD WAVE ENERGY WILL BEGIN TO IMPACT THE INNER WATERS MID
WEEK WITH SHORT PERIOD SEAS UP TO AROUND 8 FEET. WINDS WILL CONTINUE
TO INCREASE LATE WEAK WITH A 75% CHANCE OF NEAR GALE CONDITIONS BY
THURSDAY IN THE OUTER WATERS. /JHW
EKA WATCHES/WARNINGS/ADVISORIES
CA...
FROST ADVISORY UNTIL 9 AM PDT THIS MORNING FOR CAZ106-108.
NORTHWEST CALIFORNIA COASTAL WATERS...
NONE.
NOTE: THE FULL FORECAST DISCUSSION IS NOW REGULARLY ISSUED BETWEEN
10 AM/PM AND 1 PM/AM. ADDITIONAL UPDATES WILL BE ISSUED AS NEEDED.
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