471  
FXUS66 KEKA 102044  
AFDEKA  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE EUREKA CA  
144 PM PDT WED SEP 10 2025  
   
SYNOPSIS  
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO TAPER OFF  
THIS EVENING AND OVERNIGHT. THURSDAY A FEW SHOWERS AND  
THUNDERSTORMS ARE POSSIBLE OVER THE MOUNTAINS. FRIDAY AND SATURDAY  
ARE EXPECTED TO REMAIN DRY WITH MORE RAIN POSSIBLE SUNDAY AND  
MONDAY WITH DRY WEATHER RETURNING AFTER THAT.  
 
 
   
DISCUSSION  
THE LARGE UPPER LEVEL CONTINUES TO SPIN OVER  
NORTHERN CA/SOUTHERN OREGON. IN THE MID LEVEL WATER VAPOR YOU CAN  
SEE SEVERAL SMALL CIRCULATIONS ROTATING IN THE PARENT LOW. THESE  
SMALL CIRCULATIONS ARE MOVING OVER THE AREA AND HELPING TO  
ENHANCE THE SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS THE  
INTERIOR THIS AFTERNOON. THE MODELS ARE SHOWING 300 TO 500 J/KG OF  
CAPE AND PWATS ARE AROUND 1.1 INCHES. SOME OF THESE MAY PRODUCE  
LOCALLY HEAVY RAINFALL. AT THIS POINT IT LOOKS LIKE ANY SHOWERS  
THAT MAKE IT OUT TO THE COAST WILL BE FAIRLY SMALL AND WEAK.  
 
TONIGHT ANY AREAS THAT DO CLEAR OUT WILL LIKELY SEE WIDESPREAD  
LOW CLOUDS AND FOG. THURSDAY AFTERNOON THERE IS SLIGHT CHANCE FOR  
SHOWERS AND THUNDERSTORMS ONCE AGAIN, BUT THESE ARE EXPECTED TO  
BE LIMITED TO EASTERN TRINITY AND EASTERN MENDOCINO AND LAKE  
COUNTIES. CONFIDENCE IS A LOT LOWER AND COVERAGE IS EXPECTED TO  
BE A LOT LESS TOMORROW. MID LEVEL LAPSE RATES ARE NOT VERY STEEP  
AND INSTABILITY IS QUITE A BIT LOWER THAN TODAY.  
 
THURSDAY NIGHT INTO FRIDAY MORNING THERE IS EXPECTED TO BE QUITE A  
BIT OF FOG AROUND AND GOOD RH RECOVERIES. THIS WILL LIKELY TAKE  
SOME TIME TO CLEAR OUT, BUT EVENTUALLY SUNNY SKIES AND WARMER  
TEMPERATURES ARE EXPECTED IN THE AFTERNOON. LOW CLOUDS AND FOG ARE  
EXPECTED TO DIMINISH IN COVERAGE FRIDAY NIGHT INTO SATURDAY  
MORNING. DRY WEATHER IS EXPECTED FOR MUCH OF THE DAY SATURDAY AND  
TEMPERATURES ARE EXPECTED TO WARM OVER FRIDAY. THERE IS THE  
POTENTIAL FOR ANOTHER UPPER LEVEL LOW TO BRING SOME RAIN TO THE  
AREA. THE NBM POPS SHOW IT POTENTIALLY ARRIVING AS EARLY AS  
SATURDAY AFTERNOON, BUT THE DETERMINISTIC MODELS ARE SLOWER AND  
SHOW IT MORE LIKELY ON SUNDAY. CURRENT MODEL RUNS ARE SHOWING  
FAIRLY LIGHT PRECIP AND THERE IS THE POTENTIAL FOR SOME LIGHTNING  
AS WELL. ONCE THIS MOVES PAST THE AREA ON MONDAY OR TUESDAY DRY  
WEATHER IS EXPECTED TO RETURN. MKK  
 
 
   
AVIATION...(18Z TAFS)  
IFR TO LIFR CONDITIONS ALONG THE COASTAL  
TERMINALS DUE TO STRATUS AND DEGRADED VISIBILITIES. LAMP  
PROBABILITIES SHOWS HIGH CONFIDENCE (>75%) IN THE CONTINUATION OF  
MVFR CEILINGS BELOW 3KFT AGL AND ONLY A 30% PROBABILITY OF CEILINGS  
STAYING BELOW 1KFT AGL (30%) MIDDAY THROUGH THE EARLY EVENING (21Z-  
03Z. LIGHT VARIABLE WINDS ARE EXPECTED THIS MORNING BEFORE TURNING  
INTO LIGHT NORTHERLY BREEZES, POTENTIALLY INCREASING DAYTIME MIXING/  
PERIODIC SCATTERING AT TERMINAL SITES. OFFSHORE WINDS ALOFT IN DEL  
NORTE CO. COULD POTENTIALLY LEAD TO OVERNIGHT CLEARING AS WELL, MORE  
UPDATES EXPECTED AS FORECAST CONFIDENCE IMPROVES.  
 
KUKI IS OBSERVING LOW, MVFR CEILINGS. FOR KUKI AND OTHER INLAND  
TERMINALS, HREF MODEL DATA IS CONFIDENT IN THE CONTINUATION OF  
CLOUDS AROUND INLAND TERMINALS TODAY AS CONVECTION IS FORECASTED  
NEAR THE YOLLA BOLLYS AS WELL AS IN MENDOCINO AND LAKE COUNTIES.  
GUSTY OUTFLOWS/INFLOW WINDS ARE POSSIBLE, AS IS LOCALLY MODERATE TO  
HEAVY RAIN. TURBULENCE IS POSSIBLE NEAR ALL TERMINALS DUE TO MICRO-  
SCALE UPDRAFT WINDS. IN AREAS WITHOUT CONVECTION, AFTERNOON BREEZES  
ARE EXPECTED.  
 
 
   
MARINE  
AS AN AREA OF LOW PRESSURE MOVES TOWARDS THE EAST,  
NORTHERLY WINDS ARE FORECAST TO INCREASE AND REMAIN THROUGH THE END  
OF THE WEEK. SUSTAINED WINDS PEAK AT AROUND 20-25 KTS IN THE OUTER  
WATERS IN THE AFTERNOONS EACH DAY WITH GALES OF 25-30KTS POSSIBLE.  
WIND WAVES OF 6-7FT EXPECTED WITH THESE STRONG BREEZES. SMALL CRAFT  
ADVISORIES IN EFFECT THROUGH THE WEEKEND DUE TO THE STEEP WIND WAVES.  
BESIDES WIND WAVES, BOTH A NORTHWESTERLY SWELL, AND A SOUTHERLY  
SWELL ARE BEING OBSERVED TODAY, YET THEY REMAIN RELATIVELY SMALL,  
AROUND 2FT.  
 
A LONG PERIOD, NW SWELL OF 5-6 IS FORECAST TO FILL IN FRIDAY  
MORNING. COMBINED SEAS MAY REACH 7-9 FT BY FRIDAY WITH THE  
COMBINATION OF THE SWELL AND THE WIND WAVES. SEA CONDITIONS ARE  
EXPECTED TO EASE SLIGHTLY SATURDAY AFTERNOON THROUGH SUNDAY AS  
ANOTHER WEATHER SYSTEM ENTERS THE AREA EASING MARINE WINDS. COMBINED  
SEAS ARE EXPECTED TO RISE AS A LARGER MID-PERIOD NW SWELL FILLS IN  
SUNDAY EVENING/MONDAY EARLY MORNING.  
 
 
   
FIRE WEATHER  
NUMEROUS WET THUNDERSTORMS ARE MOVING THROUGH THE  
AREA THIS AFTERNOON. THESE ARE EXPECTED TO DIMINISH TONIGHT. WINDS  
WILL GENERALLY REMAIN LIGHT OVERNIGHT. ADDITIONAL THUNDER STORMS  
ARE POSSIBLE ON THURSDAY. ANY STORMS THAT DO FORM ARE EXPECTED TO  
BE DRIER. PWATS ARE LOWER AND THE BASES ARE HIGHER. FRIDAY MORNING  
THERE IS EXPECTED TO BE SOME OFFSHORE FLOW IN DEL NORTE COUNTY,  
BUT RH IS EXPECTED TO REMAIN HIGH SO THIS ISN'T EXPECTED TO BE AN  
ISSUE. SATURDAY MORNING RH RECOVERIES ARE EXPECTED TO BE LOWER,  
BUT WINDS WILL ALSO BE LIGHTER. SATURDAY NIGHT OR SUNDAY ANOTHER  
WEATHER SYSTEM IS EXPECTED TO MOVE INTO THE AREA, BUT CONFIDENCE  
IS LOW ON THE IMPACTS AT THIS POINT. MKK  
 
 
   
EKA WATCHES/WARNINGS/ADVISORIES  
 
CA...  
NONE.  
NORTHWEST CALIFORNIA COASTAL WATERS...  
SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 3 PM PDT  
THURSDAY 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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FOR FORECAST ZONE INFORMATION  
SEE THE FORECAST ZONE MAP ONLINE:  
HTTPS://WWW.WEATHER.GOV/IMAGES/EKA/ZONEMAP.PNG  
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