632  
FXUS66 KEKA 180614  
AFDEKA  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE EUREKA CA  
1114 PM PDT FRI OCT 17 2025  
   
SYNOPSIS
 
SLIGHT WARMING AND DRYING WILL PEAK SATURDAY WITH MOSTLY  
CLEAR SKIES. COOLER WEATHER AND VERY LIGHT COASTAL RAIN IS EXPECTED  
SUNDAY WITH WARMER WEATHER AGAIN EARLY NEXT WEEK.  
 

 
   
DISCUSSION
 
TRANSIENT HIGH PRESSURE WILL CONTINUE TO  
PEAK ACROSS THE AREA SATURDAY, ALLOWING FOR THE HOTTEST INTERIOR  
VALLEYS TO REACH NEAR 80. A WEAK, SHALLOW MARINE LAYER WILL PERSIST  
ALONG THE COAST. DESPITE CLEARER SKIES, CONTINUED HIGH DEWPOINTS HAVE  
PREVENTED ANY MEANINGFUL FROST FORMATION ACROSS THE INTERIOR.  
 
A WEAK UPPER LEVEL TROUGH QUICKLY MOVE ACROSS THE AREA ON SUNDAY.  
THIS WILL POOL IN COOLER AND MORE MOIST AIR ALONGSIDE MIDLEVEL  
CLOUDS. OVERALL MOISTURE ADVECTION WILL BE WEAK, HOWEVER, SUPPORTING  
ONLY VERY LIGHT RAIN RIGHT ALONG THE IMMEDIATE COAST. THERE HAS BEEN  
LITTLE CHANGE IN THE FORECAST WITH LIKELY RAIN AMOUNTS CURRENTLY  
BETWEEN 0.1 AND 0.2 INCHES IN DEL NORTE COUNTY WITH EVEN 50% OF  
MODELS SHOWING LITTLE MORE THAN DRIZZLE THERE. LOOKING SOUTH CLOSER  
TO HUMBOLDT BAY, LESS THAN 10% OF MODELS SHOW ANY WETTING RAIN.  
 
WEAK HIGH PRESSURE AND SLIGHT WARMING WILL MOST LIKELY QUICKLY  
REASSERT ITSELF EARLY NEXT WEEK, THOUGH LOW PRESSURE PASSING TO THE  
SOUTHEAST WILL LIMIT THE AMOUNT OF WARMING WITH ONLY A MODERATE  
CHANCE (50%) OF SOME HIGHS EVEN OVER 80. STRONG OFFSHORE FLOW AROUND  
THE LOW WILL LIKELY HELP BETTER DRY CONDITIONS COMPARED TO THE  
CURRENTLY HIGH STUBBORN DEWPOINTS. WIDESPREAD PATCHY FROST WILL BE  
LIKELY (60% CHANCE) MONDAY MORNING, ESPECIALLY IN TRINITY COUNTY.  
 
THERE IS INCREASING CONFIDENCE IN LONG RANGE FORECASTS THAT A  
SIGNIFICANT RAIN EVENT WILL IMPACT THE AREA LATE NEXT WEEK. THOUGH  
HIGH UNCERTAINTY REMAINS, NBM ALREADY PLACES A 95% CHANCE OF WETTING  
RAIN ALL THE WAY ALONG THE NORTH COAST WITH AN 70% CHANCE OF 3 DAY  
RAINFALL OVER 3 INCHES AND A 25% CHANCE OF 3 DAY RAINFALL OVER 5  
INCHES. DESPITE THESE HIGH TOTALS FORM THE NBM, ENSEMBLE SPREADS  
REMAINS VERY LARGE, INDICATING GREAT POTENTIAL FOR LOWER END  
SCENARIOS TO STILL BE REALIZED. ON THE STRONGER END, SUCH AN EVENT  
WOULD LIKELY BE ACCOMPANIED BY STRONG WIND WITH SUCH RAINFALL  
AMOUNTS CAPABLE OF MODERATE FLOOD IMPACTS. /JHW  
 

 
   
AVIATION...18/06Z TAFS
 
IFR TO LIFR CEILINGS AROUND 300-500 FEET  
ALONG THE COASTAL TERMINALS THIS EVENING, WHILE VISIBILITY  
VARIATIONS BETWEEN 4SM BR TO P6SM. EXPECT LOWER CEILINGS AND VSBY  
DROP TO 1/2SM IN FOG, WITH A PERIOD OF 1/4SM IN FOG POSSIBLE EARLY  
SATURDAY. THERE IS AN INCREASING CHANCE (45-55%) FOR 1/2SM OR LESS  
AFTER 12Z SATURDAY, ESPECIALLY AT KACV. LOW CEILINGS ARE EXPECTED TO  
GRADUALLY LIFT AND SCATTERED AFTER 18Z. HOWEVER, MICROSCALE EDDY MAY  
KEEP THE SHORELINE WITH LOW CLOUDS MOVING IN AND OUT, ESPECIALLY IN  
THE VICINITY OF HUMBOLDT BAY. ONSHORE FLOW WILL PUSH BACK INLAND THE  
STRATUS AND FOG LATER IN THE AFTERNOON AND EVENING.  
 
FOR INLAND AREAS, INCLUDING UKI, MAINLY VFR CONDITIONS ARE EXPECTED  
TO PREVAIL WITH LIGHT BREEZES. /ZVS  
 

 
   
MARINE
 
NORTHERLY WINDS WILL GRADUALLY DIMINISH TONIGHT THROUGH  
SATURDAY. GENERALLY LIGHT TO MODERATE BREEZES IS EXPECTED BY  
SATURDAY AFTERNOON, WITH VERY LIGHT AND VARIABLE WINDS NEARSHORE.  
 
A LONG PERIOD NORTHWEST SWELL AT 2-5 FEET AT 18-20 SECONDS CONTINUE  
BUILDING ACROSS THE WATERS THIS EVENING, AND PEAKING TO 8-10 FEET AT  
16 SECONDS SATURDAY AFTERNOON.  
 
SATURDAY NIGHT INTO SUNDAY MORNING, SOUTHERLY WINDS WILL DEVELOPED  
BRIEFLY ACROSS THE OUTER WATERS AS A WEAK FRONTAL SYSTEM MOVES  
THROUGH, BEFORE SHIFTING TO NORTHERLIES SATURDAY AFTERNOON.  
NORTHERLY WINDS INCREASE AGAIN ON SUNDAY AFTERNOON AND CONTINUE  
STRENGTHENING THROUGH EARLY NEXT WEEK. GALE STRENGTH GUSTS ARE  
FORECAST AROUND AND SOUTH OF CAPE MENDOCINO SUNDAY AFTERNOON THROUGH  
SUNDAY NIGHT.  
 
NORTHERLY WINDS WILL REMAIN SOMEWHAT STRENGTHENED INTO MID NEXT  
WEEK. THE NORTHERLY WIND PATTERN BREAKS DOWN THEREAFTER AS A STRONG  
TROUGH TAKES AIM AT THE VICINITY OF N CA. STRONG SOUTHERLY WINDS ARE  
POSSIBLE THURSDAY OR FRIDAY IF THIS SYSTEM TAKE A MORE SOUTHERLY  
TRACK. CHANCES FOR AT LEAST SUSTAINED GALE STRENGTH SOUTHERLIES AND  
LARGE SURF CONTINUE TO INCREASE THROUGH THE WEEKEND WITH MODELED  
POTENT NE PAC CYCLONES.  
 
A LONG PERIOD WEST NORTHWEST SWELL WILL BEGIN TRICKLING IN LATE THIS  
AFTERNOON WITH 20 SECOND PERIOD FORERUNNERS. THIS SWELL WILL  
CONTINUE BUILDING THROUGH SATURDAY AFTERNOON, PEAKING AROUND 10 FT  
AT 16 SECONDS. A SECOND LARGER SWELL MOVE IN LATE SUNDAY THROUGH  
MONDAY, AND BREAKERS MAY REACH 20 FEET THROUGH THAT PERIOD.  
ADDITIONAL LARGE SWELLS ARE THEN LIKELY THROUGH NEXT WEEK WITH AN  
ACTIVE PACIFIC STORM TRACK. /ZVS&JJW  
 

 
   
BEACH HAZARDS
 
A BEACH HAZARD STATEMENT IS IN EFFECT THROUGH  
SATURDAY EVENING. A LONG PERIOD WESTERLY SWELL WILL CURRENTLY MOVING  
ACROSS THE WATERS WILL PEAK TO 8 TO 10 FEET AT 16 SECONDS SATURDAY  
AFTERNOON. THIS HIGH ENERGY SWELL HAS THE POTENTIAL TO BRING  
MODERATE RISK OF SNEAKER WAVES, ESPECIALLY LATE AFTERNOON/ EARLY  
EVENING ON SATURDAY. SHORTER PERIOD NW SWELL OF 5-8 FT AT 7-9  
SECONDS MAY INITIALLY MITIGATE THE RISK DURING THE MORNING AND  
AFTERNOON HOURS ON SATURDAY. SNEAKER WAVES ARE A UNIQUE HAZARD, WITH  
MANY MINUTES BETWEEN WAVES. PAY ATTENTION AND STAY ABOVE THE HIGH  
WATER LINE AND ANY WET SAND TO STAY SAFE. IF THE GROUND IS WET,  
WAVES HAVE SURGED THERE RECENTLY. STAY SAFE AND NEVER TURN YOUR BACK  
ON THE OCEAN! A POTENTIALLY LARGER SWELL IS THEN FORECAST TO MOVE IN  
LATE SUNDAY THROUGH MONDAY./ZVS  
 

 
   
EKA WATCHES/WARNINGS/ADVISORIES
 
 
CA...  
BEACH HAZARDS STATEMENT THROUGH SATURDAY EVENING FOR CAZ101-  
103-104-109.  
 
NORTHWEST CALIFORNIA COASTAL WATERS...  
SMALL CRAFT ADVISORY UNTIL NOON PDT SATURDAY FOR PZZ450-455.  
 
SMALL CRAFT ADVISORY UNTIL 11 PM PDT SATURDAY FOR PZZ470.  
 
SMALL CRAFT ADVISORY UNTIL 11 PM PDT SUNDAY 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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