460
FXUS66 KEKA 290849
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
149 AM PDT WED APR 29 2026
SYNOPSIS
THE POSSIBILITY OF INTERIOR THUNDERSTORMS INCREASES
FRIDAY INTO SUNDAY AS AN AREA OF LOW PRESSURE BEGINS TO ORGANIZE
BY THE END OF THE WEEK.
DISCUSSION
MARINE STRATUS FILLING IN OVERNIGHT INTO WEDNESDAY
MORNING AS LOW LEVEL INVERSION IS FURTHER ENHANCED BEHIND HIGH
PRESSURE AND SUBSIDENCE, ALBEIT A WEAK RIDGING PATTERN WITH GAPS NOT
ENCOURAGING VORTICITY. THE GRADIENT WILL NOT BE PARTICULARLY STEEP
ACROSS ISOBARS UNTIL A MORE UNIFORMED AND DEFINED SYSTEM BEGINS TO
FORM SATURDAY, STRENGTHENING SUNDAY. THAT SAID, GFS IS HIGHLIGHTING
MUCAPE AND RH WITH AN EMBEDDED SHORTWAVE LATE FRIDAY AFTERNOON INTO
THE EARLY EVENING FOR THE INTERIOR AREAS OF SISKIYOU, WESTERN
TRINITY AND IN A LINEAR SUCCESSION DOWN TO NORTHEASTERN MENDOCINO
AND WESTERN LAKE COUNTY. THE MEAN SURFACE CAPE FROM NBM IS
HIGHLIGHTING MOST OF THE INTERIOR STARTING FRIDAY WHICH COULD BE
ATTRIBUTED TO SURFACE HEATING AND PARCEL BUOYANCY BUT WITH
INCREASING HUMIDITY THERE COULD BE IMPLICATIONS FOR THUNDERSTORM
ACTIVITY. ENSEMBLES ALSO SHOW A RISE IN PWAT VALUES RISING INTO THE
WEEKEND FOR WHAT COULD BE THUNDERSTORMS WITH THE CHANCE OF LIGHTNING
FRIDAY THROUGH MONDAY AT LEAST. NBM BEGINS TO INCLUDE DEL NORTE
SATURDAY EARLY EVENING FOR 15% AND GREATER CHANCES OF THUNDER WHICH
ALSO COINCIDES WITH HIGH CAPE VALUES IN THE 700-800J/KG RANGE.
/EYS
AVIATION...00Z TAFS
STRATUS EXPANDED OUT FROM HUMBOLDT BAY
TUESDAY EVENING. CONFIDENCE IS GROWING ON SOUTHERLY RETURN FLOW FROM
A COASTAL EDDY TO ADVECT STRATUS UP TO CEC THROUGH WEDNESDAY
MORNING. MVFR TO IFR CIGS EXPECTED AT ACV (53% CHANCE FOR IFR).
THERE IS A LESSER CHANCE (20%) FOR LIFR IN THE 13-16Z WEDNESDAY
TIMEFRAME AT ACV. CIGS AT CEC WILL MAINLY RANGE IN MVFR LEVELS FOR A
CHANCE (26%) FOR IFR. UKI IS EXPECTED TO REMAIN VFR WITH VERY LITTLE
INDICATIONS FOR A SURGE PUSH OF STRATUS UP THE RUSSIAN RIVER VALLEY.
CHANCES FOR THIS OCCURRENCE AND RESULTING MVFR CIGS ARE 21%.
MARINE
NORTHERLY WINDS WILL CONTINUE THEIR STRENGTHENING
TREND THROUGH FRIDAY. GALE TO NEAR GALE CONDITIONS WILL BE POSSIBLE
IN THE WATERS BY THURSDAY. THE INNER WATER BUOYS ARE RECORDING UP TO
8 FT SHORT PERIOD SEAS TUESDAY NIGHT, WITH PROPAGATION FROM THE
OUTER ZONES WHERE THE STRONGER NORTHERLIES CONTINUE. SMALL CRAFT
ADVISORIES REMAIN IN ALL ZONES TO COVER THE WIND AND STEEP SEA
THREAT TO SMALLER VESSELS.
A BRIEF PERIOD OF LOWER SEAS IS POSSIBLE WEDNESDAY MORNING AND EARLY
AFTERNOON SO THE ADVISORIES END EARLY WEDNESDAY MORNING. HOWEVER,
WINDS AND SEAS WILL BUILD FURTHER BY WEDNESDAY AFTERNOON AND
ADVISORIES WILL NEED TO ONCE AGAIN BE ISSUED FOR THOSE AREAS
STARTING AS EARLY AS MID AFTERNOON ON WEDNESDAY. PERSISTENT WINDS
OVER THE OUTER WATERS WILL KEEP SEAS ELEVATED AND WINDS IN SMALL
CRAFT CRITERIA TO NEAR GALE WEDNESDAY INTO WEDNESDAY NIGHT. AS THE
PRESSURE GRADIENT FURTHER STRENGTHENS, GALE FORCE GUSTS WILL BECOME
LIKELY THURSDAY AFTERNOON THROUGH FRIDAY NIGHT IN THE OUTER ZONES.
GALE CONDITIONS MAY LINGER INTO SATURDAY BEFORE WINDS BEGIN
SUBSTANTIALLY EASING LATE SATURDAY AFTERNOON.
EKA WATCHES/WARNINGS/ADVISORIES
CA...
NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...
SMALL CRAFT ADVISORY UNTIL 5 AM PDT EARLY THIS MORNING FOR
PZZ450.
SMALL CRAFT ADVISORY UNTIL 6 AM PDT EARLY THIS MORNING FOR
PZZ455.
SMALL CRAFT ADVISORY UNTIL 3 PM PDT THURSDAY FOR PZZ470.
GALE WATCH FROM THURSDAY AFTERNOON THROUGH LATE FRIDAY
NIGHT FOR PZZ470.
SMALL CRAFT ADVISORY UNTIL 11 PM PDT THIS EVENING FOR
PZZ475.
GALE WATCH FROM THIS EVENING THROUGH LATE FRIDAY NIGHT FOR
PZZ475.
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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