521
FXUS66 KEKA 212133
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
233 PM PDT WED OCT 21 2026
KEY MESSAGES
* LIGHT RAIN SHOWERS ARE EXPECTED TO BECOME MORE WIDESPREAD
TONIGHT AND THURSDAY MORNING BEFORE TAPERING OFF THURSDAY
AFTERNOON.
* DRY, COOLER AND BREEZY CONDITIONS ARE EXPECTED FRIDAY WITH
FROST OR FREEZING TEMPERATURES POSSIBLE FRIDAY NIGHT.
* THERE IS THE POTENTIAL FOR A PATTERN CHANGE TO COOLER AND WETTER
WEATHER. THIS MAY START AS EARLY AS SUNDAY OR MORE LIKELY HOLD
OFF UNTIL EARLY OR MID NEXT WEEK.
SYNOPSIS
A FEW SHOWERS CONTINUE THIS AFTERNOON WITH MORE
WIDESPREAD SHOWERS EXPECTED LATER TONIGHT AND THURSDAY MORNING.
THURSDAY AFTERNOON THESE SHOWERS WILL TAPER OFF FROM WEST TO EAST.
THIS WILL SET UP A COOL AND DRY FRIDAY WITH FROST LIKELY FRIDAY
NIGHT. WARM AND DRY CONDITIONS ARE EXPECTED SATURDAY WITH THE NEXT
CHANCE FOR RAIN POSSIBLY AS EARLY AS SUNDAY.
DISCUSSION
A BAND OF LIGHT RAIN SHOWERS HAS SET UP FROM
HUMBOLDT BAY DOWN THROUGH NORTHERN LAKE COUNTY THIS AFTERNOON.
SOME OF THESE SHOWERS ARE STRONGER AND HAVE PRODUCED A FEW
LIGHTNING STRIKES IN NORTHERN LAKE COUNTY. THESE ARE EXPECTED TO
DIMINISH LATER THIS AFTERNOON AND EARLY IN THE EVENING. LATE IN
THE EVENING AND OVERNIGHT MORE WIDESPREAD SHOWERS ARE EXPECTED.
THE NBM IS SHOWING A PROBABILITY OVER A WETTING RAIN (OVER 0.10
INCHES) OF 40 TO 70 PERCENT SOUTH AND EAST OF A LINE FROM BIG BAR
TO REDWAY. IT LOOKS LIKE SOME RAIN WILL MAKE IT FARTHER WEST AND
OUT TO COASTAL HUMBOLDT, BUT PROBABILITIES ARE LOWER AND AMOUNTS
ARE LIKELY TO BE LESS. THURSDAY BY MID TO LATE MORNING THE BACK
EDGE OF THE RAIN IS EXPECTED TO START TO PUSH EAST. NEW MODELS RUN
SHOW THIS TAKING MOST OF THE EVENING TO GET OUT OF TRINITY
COUNTY. BEHIND THE FRONT AREAS THAT DO MANAGE TO CLEAR ARE
EXPECTED TO VALLEY FOG. THE CHILLY AIRMASS COULD ALLOW SOME AREAS
TO DROP INTO THE MID 30S AND SEE FROST, BUT MORE LIKELY THEY WILL
JUST FOG UP. CLOSER TO THE COAST AND ABOVE A COUPLE THOUSAND FEET
THE RIDGES ARE EXPECTED TO CLEAR OUT AND SEE BREEZY EASTERLY
WINDS. FRIDAY IS EXPECTED TO BE SEE QUITE OF DRYING, BUT
TEMPERATURES ARE EXPECTED TO REMAIN ONLY IN THE 60S. THIS DRIER
AIR WILL SET UP THE AREA FOR A CHILLY NIGHT FRIDAY INTO SATURDAY
MORNING. EASTERLY WINDS WILL LIKELY KEEP THE COAST CLEAR AND THE
RIDGES DRY.
SUNDAY AND INTO EARLY NEXT WEEK THE FORECAST REMAINS HIGHLY
UNCERTAIN. THE MODELS HAVE BACKED OFF FROM THE WETTEST SOLUTIONS.
HOWEVER SOME OF THE MODEL CLUSTERS CONTINUE TO SHOW A TENTH TO A
QUARTER OF AN INCH OF RAIN ON SUNDAY. THE MODELS ARE STILL SHOWING
A FAIRLY EVEN SPLIT BETWEEN A LARGE RIDGE AND TROUGH OVER THE
AREA. THIS COULD MEAN A DIFFERENCE IN HIGH TEMPERATURES OF 55 IN
THE TROUGH OR OVER 75 UNDER THE RIDGE. BY TUESDAY OR WEDNESDAY
AN INCREASING NUMBER OF THE CLUSTER MEMBERS SHOWING A TROUGH
MOVING INTO THE AREA BRINGING THE POTENTIAL FOR SOME RAIN. THIS
WILL DEFINITELY BE A TIME PERIOD TO WATCH AND MAY BE THE EARLY
SIGNS OF A MORE SIGNIFICANT PATTERN CHANGE. MKK
AVIATION...18Z
WHILE GENERAL OVERCAST SKIES ARE ANTICIPATED FOR
NORTHWEST CALIFORNIA THROUGH THE TAF PERIOD, VFR CONDITIONS ARE
ANTICIPATED THIS AFTERNOON. AN APPROACHING LOW PRESSURE SYSTEM TO
THE SOUTH OF THE REGION HAS AIDED IN SCATTERING AND LIFTING THE LOW
CLOUDS FROM THIS MORNING. LIGHT RAIN SHOWERS AND LOWER CEILINGS ARE
EXPECTED FOR THE OVERNIGHT HOURS WITH IFR/LIFR CONDITIONS
ANTICIPATED FOR COASTAL TERMINALS BY LATE THIS EVENING OR VERY EARLY
TOMORROW MORNING. MVFR AND MORE FREQUENT SHOWERS CAN BE EXPECTED FOR
SOUTHERN MENDOCINO AND LAKE COUNTIES OVERNIGHT. /JLW
MARINE
A MID PERIOD WESTERLY SWELL WILL CONTINUE TO GRADUALLY
SUBSIDE OVER THE NEXT DAY. AN UPPER LOW WILL CONTINUE MOVING INTO
CENTRAL CALIFORNIA THROUGH THE END OF THE WEEK. NORTHERLY WINDS AND
SEAS WILL REMAIN BELOW SMALL CRAFT CONDITIONS AS THIS LOW MOVES ON
SHORE OVER THE NEXT 24 HOURS. BY TOMORROW, NORTHERLY WINDS WILL
BEGIN TO INCREASE, ESPECIALLY BY TOMORROW AFTERNOON, AS A DRY COLD
FRONT PASSES. HIGH PRESSURE WILL BEGIN TO REBUILD INTO THE REGION
BEHIND THIS FRONT. ELEVATED WINDS AND STEEP SEAS ARE ANTICIPATED
THURSDAY THROUGH SATURDAY WITH A 60 TO 80 PERCENT CHANCE FOR
WIDESPREAD GALE FORCE GUSTS BY VERY LATE THURSDAY/EARLY FRIDAY TO
FRIDAY AFTERNOON. /JLW
EKA WATCHES/WARNINGS/ADVISORIES
CA...
NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...
SMALL CRAFT ADVISORY FROM 6 PM THURSDAY TO 9 PM PDT FRIDAY
FOR PZZ450-455.
SMALL CRAFT ADVISORY FROM 9 AM TO 6 PM PDT THURSDAY FOR
PZZ470.
GALE WARNING FROM 6 PM THURSDAY TO 9 PM PDT FRIDAY FOR
PZZ470.
SMALL CRAFT ADVISORY FROM 9 AM TO 9 PM PDT THURSDAY FOR
PZZ475.
GALE WARNING FROM 9 PM THURSDAY TO 9 PM PDT FRIDAY 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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