466
FXUS66 KEKA 160700
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
1200 AM PDT SAT AUG 16 2025
SYNOPSIS
A WEAK EARLY SEASON COLD FRONT WILL BRING SLIGHT, LIGHT
RAIN POTENTIAL TO THE COAST EARLY TODAY WITH SHOWERS POSSIBLE
INLAND. ANY MEASURABLE RAIN POTENTIAL WILL REMAIN NORTH OF CAPE
MENDOCINO. WARMER AND DRIER WEATHER GRADUALLY RETURNS NEXT WEEK.
DISCUSSION
THE EFFECTS OF AN APPROACHING UPPER LEVEL
TROUGH WILL RAMP UP TONIGHT THROUGH THE WEEKEND. GUSTY NORTHWEST
WINDS ARE EXPECTED TO CONTINUE THROUGH SAT. AFTERNOON, ESPECIALLY OR
THE SOUTHERN HALF OF THE AREA WITH GUSTS OF 30 TO 40 MPH IN EXPOSED
AREAS. CONDITIONS HAVE ALSO CONTINUED TO COOL AND MOISTEN WITH
MARINE AIR ADVECTING INLAND. HIGH TEMPERATURES EXPECTED FROM 85 -
90\F INLAND WITH THE DEEP MARINE LAYER ALLOWING WARMING ALONG THE
COAST TO THE MID/HIGH 60S BY THE AFTERNOON. MID AND UPPER LEVEL
CLOUDS ARE EXPECTED TO CONTINUE WITH RAIN SHOWERS THROUGH SUNDAY
EARLY MORNING.
A PLUME OF MOISTURE WILL MOVE ONSHORE EARLY THIS MORNING WITH
IMPRESSIVE PWATS FOR AUGUST BETWEEN 1 AND 1.5 INCHES. ACTUAL
INSTABILITY AND SYNOPTIC LIFT WILL BE MARGINAL AT BEST, BUT
NORTHWEST WIND AT THE SURFACE SHOULD HELP PRODUCE ENOUGH LIFT TO
GENERATE LIGHT PRECIPITATION ALONG THE COAST THIS MORNING. THERE IS
AN 80% CHANCE FOR AT LEAST TRACE AMOUNTS OF RAIN ALONG THE DEL NORTE
COAST AND A 60% CHANCE OF WETTING RAIN (>0.1"). SIMILARLY FOR
HUMBOLDT BAY, THERE IS A 65% CHANCE OF AT LEAST TRACE AMOUNTS OF
RAIN AND A 30% CHANCE OF WETTING RAIN (>0.1"). DESPITE THE RAIN,
INCREASED INSTABILITY WILL DISRUPT THE MARINE LAYER, LIKELY HELPING
IN BETTER COASTAL CLEARING THIS WEEKEND, AT LEAST WHEN ITS NOT
RAINING. CHANCES OF WETTING RAIN QUICKLY DIMISH INLAND AND FURTHER
SOUTH WITH NEAR 0% CHANCE OF ANY WETTING RAIN SOUTH OF THE KING
RANGE.
THE TIMING OF THE RAIN SHOWS A MORNING ARRIVAL ON THE COAST WITH
MOISTURE PUSHING INLAND BY THE AFTERNOON. ANY RAIN FALLING OVER THE
INTERIOR WILL MOST LIKELY FALL AS SCATTERED AND INCONSISTENT
SHOWERS. THERE IS A GENERAL 40% CHANCE OF ANY GIVEN POINT IN TRINITY
COUNTY SEEING WETTING RAIN (>0.1"), THOUGH ACTUAL COVERAGE WOULD BE
VERY SPOTTY AT BEST. COLDER AIR MOVING IN BEHIND THE MOISTURE WILL
DEEPEN INSTABILITY, BRINING A VERY SLIGHT CHANCE OF THUNDERSTORMS
(<15%) SATURDAY EVENING AND AGAIN SUNDAY AFTERNOON FOR EASTERN
TRINITY COUNTY AND NE MENDOCINO.
THERE IS HIGH MODEL CONFIDENCE THAT WEAK HIGH PRESSURE BRINGING
WARMER AND DRIER WEATHER WILL GRADUALLY REASSERT ITSELF THROUGH NEXT
WEEK. THOUGH THERE IS A RANGE OF UNCERTAINTY BY THE END OF NEXT
WEEK, THERE IS LITTLE CHANCE OF EXTREME HEAT (20% OR LESS) RETURNING
WITH HIGHS MOST LIKELY STAYING JUST AT OR BELOW 100 FOR INTERIOR
LOCATIONS LATE NEXT WEEK. /JHW
AVIATION...(06Z TAFS)
MID TO HIGH CLOUDS WILL MOVE OVER THE
REGION THROUGH SATURDAY AS A FRONT APPROACHES. DRIZZLE TO LIGHT RAIN
CAN BE EXPECTED FOR COASTAL TERMINALS NORTH OF CAPE MENDOCINO EARLY
SATURDAY MORNING WITH IFR TO LIFR CONDITIONS. SOME SHOWERS COULD POP
UP AROUND THE HIGHER TERRAIN AREAS OF TRINITY COUNTY. GUSTY NORTH TO
NORTHWESTERLY WINDS ARE FORECAST FOR TERMINALS IN SOUTHERN INTERIOR
MENDOCINO AND LAKE COUNTIES THROUGH THE TAF PERIOD WITH A PEAK INTO
SATURDAY AFTERNOON.
MARINE
MODERATE TO STRONG NORTHERLY WINDS WILL CONTINUE TO
DIMINISH IN THE SOUTHERN WATERS, WHILE LIGHTER WINDS CONTINUE ACROSS
THE NORTHERN WATERS. NORTHERLY WINDS ARE EXPECTED TO CONTINUALLY
DIMINISH INTO SATURDAY. SHORT-PERIOD SEAS WILL CONTINUE TO SUBSIDE
INTO EARLY SATURDAY AS THE WINDS DIMINISH.
FOR THE WEEKEND, NORTHERLIES WILL BE GENERALLY LIGHT TO MODERATE
ACROSS THE COASTAL WATERS. FRESH BREEZES ARE FORECAST IN THE LEE OF
CAPE MENDOCINO EACH AFTERNOON. A NW SWELL WILL BUILD INTO THE
COASTAL WATERS BY SATURDAY AFTERNOON, PEAKING TO AROUND 5 TO 6 FEET
AT AROUND 10 SECONDS SATURDAY NIGHT/EARLY SUNDAY.
RELATIVELY CALM CONDITIONS WITH LIGHT TO GENTLE BREEZES AND LOW SEAS
WILL CONTINUE FOR EARLY TO MID NEXT WEEK, BEFORE NORTHERLY WINDS
INCREASE AGAIN BY MID WEEK. /ZVS
FIRE WEATHER
NORTHWEST WINDS GUSTING OVER 30 MPH IN EXPOSED AREAS
AND ALONG RIDGELINES WILL CONTINUE TO ENHANCE FIRE DANGER,
PARTICULARLY AROUND THE RUSSIAN RIVER VALLEY AND CLEAR LAKE WHERE
WINDS ARE HIGHEST. THAT SAID, GUSTY WINDS ARE ALSO BRINGING WITH
THEM COOLER AND MORE MOIST MARINE AIR. RAIN CHANCES AND VERY HIGH RH
RECOVERIES OVER THE WEEKEND WILL GREATLY SUBDUE FIRE WEATHER
CONCERNS, THOUGH SLIGHT CHANCES FOR THUNDERSTORMS OVER TRINITY
COUNTY SATURDAY EVENING AND AGAIN SUNDAY AFTERNOON (15% CHANCE) WILL
GENERATE SOME POSSIBLE IGNITIONS. OTHERWISE, WARM AND DRY WEATHER
WILL GRADUALLY RETURN THROUGH NEXT WEEK. /JHW
EKA WATCHES/WARNINGS/ADVISORIES
CA...
NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...
NONE.
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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