276  
FXUS66 KEKA 010744  
AFDEKA  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE EUREKA CA  
1244 AM PDT WED OCT 1 2025  
   
SYNOPSIS  
A FRONTAL PASSAGE WILL CONTINUE TO GENERATE RAINSHOWERS  
ON WEDNESDAY, AND POTENTIALLY THURSDAY, BEFORE GIVING WAY TO DRY  
WEATHER ON FRIDAY AND HOLD THROUGH THE WEEKEND.  
 
 
   
DISCUSSION  
THE COLD FRONTAL PASSAGE YESTERDAY BROUGHT STRONG  
WINDS AND SOME WETTING RAIN TO MOST OF THE FORECAST AREA. THE  
SYNOPTIC SCALE, UPPER LEVEL TROUGH AND COOLER AIR WILL LINGER OVER  
NW CALIFORNIA BEHIND THE FRONT TODAY. SHALLOW ATMOSPHERIC  
INSTABILITY MIXED WITH ONSHORE WESTERLY FLOW WILL LIKELY RESULT IN  
CONTINUED SHOWER ACTIVITY INTO WED NIGHT WITH ADDITIONAL RAIN  
TOTALS AROUND 0.10" FOR THE NORTH COAST AND UP TO 0.25" IN  
SOUTHERN MENDOCINO & LAKE COUNTIES. ON THURSDAY, THE UPPER TROUGH  
WILL BEGIN TO MIGRATE AFTER SITTING OFF THE COAST OF BRITISH  
COLUMBIA LEADING TO A DECREASE IN OVERALL RAINFALL. HOWEVER,  
REMAINING MOISTURE AND DAYTIME HEATING COULD PRODUCE SOME  
RAINSHOWERS IN THE INTERIOR, SPECIFICALLY TRINITY. HOWEVER, MODEL  
SOUNDINGS SHOW UNFAVORABLE LAPSE RATES FOR STORMS.  
 
FRIDAY, THROUGH THE WEEKEND, AND INTO EARLY NEXT WEEK DRY WEATHER IS  
EXPECTED TO RETURN. STRONG HIGH PRESSURE BUILDS OVER THE EASTERN  
PACIFIC. THE FORECAST UNCERTAINTY LIES IN THE TRAJECTORY OF THIS  
UPPER LEVEL LOW. IT ALSO LOOKS LIKE THERE WILL BE SOME WEATHER  
SYSTEMS MOVING DOWN THE EAST SIDE OF THE RIDGE IN AN INSIDE SLIDER  
PATTERN. THIS MAY CREATE OFFSHORE FLOW BRINGING CLEAR SKIES AND DRY  
CONDITIONS, ESPECIALLY FOR COASTAL AREAS. THESE CLEAR AND DRY  
CONDITIONS WILL ALSO BRING THE POTENTIAL FOR FROST OR FREEZING  
TEMPERATURES IN THE VALLEYS. THIS WILL BE HIGHLY DEPENDENT ON HOW  
MUCH DRYING THERE IS, BUT IT IS STARTING TO LOOK LIKE WE WILL SEE  
FROST AT LEAST IN THE COLDER AREAS IN THE INTERIOR.  
 
 
   
AVIATION...06Z TAF  
POST FRONTAL CONDITIONS HAVE KEPT AVIATION  
CONDITIONS VARIABLE ALL ACROSS THE AREA. CONDITIONS HAVE SO FAR  
MOSTLY REMAINED VFR WITH ONLY BRIEF MVFR PERIODS IN PASSING SHOWERS.  
EARLIER STRONG WIND SHEAR HAS NOW DIED DOWN AND WILL CONTINUE TO  
DECREASE THROUGH EARLY WEDNESDAY.  
 
AS WINDS CONTINUE TO DECREASE AND RAIN ACTIVITY LESSENS, CEILINGS  
WILL MOST LIKELY LOWER BY SUNRISE, WITH IFR CONDITIONS MOST LIKELY  
ALONG THE COAST. THAT SAID, THERE IS WIDE MODEL DISAGREEMENT WITH  
WITH CEILINGS HEIGHTS POSSIBLE ANYWHERE BETWEEN 500 AND 2500 FEET BY  
MID MORNING. RECENT RAIN HAS ALSO HELPED PRODUCE IFR CEILING IN MANY  
INTERIOR VALLEYS OVERNIGHT. ANY IFR CEILINGS WILL MOST LIKELY  
GRADUALLY LIFT THROUGH THE DAY WEDNESDAY, BUT TRUE SCATTERING TO  
VFR REMAINS UNLIKELY (30% CHANCE).  
 
 
   
MARINE  
A COLD FRONT HAS GENERALLY EXITED THE WATERS LATE TUESDAY  
WITH ONLY FEW LINGERING GUSTS OVER 20 KTS. STEEP SHORT PERIOD SEAS  
WILL QUICKLY FALL EARLY WEDNESDAY MORNING. THIS WILL LEAD TO A SHORT  
CALM PERIOD DURING THE MORNING HOURS, ESPECIALLY FOR THE SOUTHERN  
WATERS. BY EARLY WEDNESDAY AFTERNOON, HOWEVER, A MID PERIOD SWELL  
WILL QUICKLY BUILD OVER 12 FEET AND RETURN STEEP SEA CONDITIONS TO  
ALL WATERS. OTHERWISE, WINDS WILL BE MOSTLY GENTLE WEDNESDAY.  
 
JUST IN TIME FOR THE SWELL TO DECAY ON THURSDAY, MODERATE, NORTHERLY  
WINDS WILL BUILD ACROSS THE AREA, ESPECIALLY IN THE SOUTHERN WATERS  
WHERE NEAR GALE FORCE CONDITIONS ARE MOST LIKELY JUST DOWNWIND OF  
CAPE MENDOCINO. STRONG NORTHERLY WINDS WILL SPREAD NORTHWARD LATE ON  
FRIDAY WITH STEEP SHORT PERIOD SEAS INN ALL WATERS HEADED INTO THE  
WEEKEND. /JHW  
 
 
   
EKA WATCHES/WARNINGS/ADVISORIES  
 
CA...  
WIND ADVISORY UNTIL 1 AM PDT EARLY THIS MORNING FOR CAZ101-  
102-104>106.  
 
BEACH HAZARDS STATEMENT FROM 8 AM PDT THIS MORNING THROUGH  
THURSDAY AFTERNOON FOR CAZ101-103-104.  
 
NORTHWEST CALIFORNIA COASTAL WATERS...  
SMALL CRAFT ADVISORY UNTIL 5 PM PDT THURSDAY FOR PZZ450-470.  
 
SMALL CRAFT ADVISORY UNTIL 2 AM PDT EARLY THIS MORNING FOR  
PZZ455-475.  
 
 
 
 
 
NOTE: THE FULL FORECAST DISCUSSION IS NOW REGULARLY ISSUED BETWEEN  
10 AM/PM AND 1 PM/AM. ADDITIONAL UPDATES WILL BE ISSUED AS NEEDED.  
 
VISIT US AT HTTPS://WWW.WEATHER.GOV/EUREKA  
 
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FOR FORECAST ZONE INFORMATION  
SEE THE FORECAST ZONE MAP ONLINE:  
HTTPS://WWW.WEATHER.GOV/IMAGES/EKA/ZONEMAP.PNG  
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