416
FXUS66 KEKA 101131
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
431 AM PDT SAT OCT 10 2026
AVIATION...12Z UPDATE
A STRATUS DECK HAS MADE ITS WAY TO
HUMBOLDT BAY EARLY THIS MORNING BRINGING MVFR CONDITIONS. A DRY COLD
FRONTAL BOUNDARY MAKING SOUTHWARD THROUGH THE MORNING WILL HELP
MIX THIS LAYER AWAY LEADING TO WIDE SPREAD VFR CONDITIONS FOR
COASTAL TERMINALS. NORTHERLY WINDS WILL BUILD TO GUSTS UP TO
30KTS AFTER THIS FRONTAL PASSAGE. THESE WINDS HAVE THE POTENTIAL
TO TRANSPORT HAZE FROM LARGE BREAKING WAVES ALONG THE COAST OVER
TERMINALS, YET MINIMAL DEGRADATION IS EXPECTED. INLAND AREAS CAN
ALSO EXPECT VFR CONDITIONS WITH ENHANCED NORTH WINDS. THESE WINDS
ARE ALSO CAPABLE OF LOW LEVEL TURBULENCE NEAR TERMINALS,
ESPECIALLY DURING THE PEAK OF THE AFTERNOON. DS
PREV DISCUSSION
/ISSUED 237 AM PDT SAT OCT 10 2026/
KEY MESSAGES...
* AN INCOMING DRY COLD FRONT WILL BRING MUCH COOLER CONDITIONS BY
FRIDAY AND THE WEEKEND.
* STRONG, GUSTY NORTH WINDS EXPECTED CLOSE TO SHORE, ALONG RIDGES,
AND IN CHANNEL TERRAIN THIS WEEKEND.
* NO WETTING RAIN FORECAST FOR THE NEXT 10 DAYS.
SYNOPSIS...AN INCOMING DRY COLD FRONT WILL CAUSE STRONG NORTH
WINDS THROUGH THE WEEKEND. DRAMATICALLY COOLER TEMPERATURES
ARE TO BE EXPECTED, WITH CHANCES FOR FROST OR SUB FREEZING
TEMPERATURES FOR THE INTERIOR THROUGH LATE NEXT WEEK. CHANCES FOR
WETTING RAIN REMAIN NEAR 0% THROUGH THE EXTENDED FORECAST.
DISCUSSION...THIS WEEKEND WEATHER WILL BE DOMINATED BY THE IMPACTS
OF AN UPPER LEVEL TROF ENTERING THE PACNW. WHILE THE CENTER OF THIS
LOW PRESSURE SYSTEM WILL BE FARTHER NORTH, OVER WA AND OR, SHORTWAVE
DISTURBANCES WILL FLOW OVER NW CA ENHANCING ATMOSPHERIC MIXING AND
LEADING TO GUSTY CONDITIONS. GUSTY NORTH WINDS WILL BE STRONG
SATURDAY AND SUNDAY WITH COASTAL AREAS AND RIDGES EXPERIENCING THE
BULK OF THE FLOW. HIGHER RESOLUTION MODELS ALSO ARE SHOWING THESE
WINDS MIXING DOWN INTO RIVER VALLEYS THAT ARE EXPOSED TO THE
DIRECTION OF FLOW. WIND SPEEDS WILL BE STRONG, BETWEEN 25-35MPH IN
THE AFTERNOON, WHILE STILL REMAINING BELOW LEVELS NEEDED FOR A WIND
ADVISORY. COOLER TEMPERATURES ARE ALSO EXPECTED WITH THIS FEATURE
THROUGH THE WEEKEND INTO EARLY NEXT WEEK.
BESIDES THE STRONGER WINDS, MORNINGS ARE EXPECTED TO BE CHILLY.
THESE COLDER TEMPERATURES HAVE THE POTENTIAL TO CAUSE SOME LOCALIZED
FROST FOR INLAND VALLEYS. CONFIDENCE IS HIGH ON TEMPERATURES
DROPPING BELOW 35DEGF FOR MUCH OF TRINITY AND NE MENDOCINO. THAT
SAID, FROST COULD BE STOPPED BY CLOUD DEVELOPMENT IN THESE VALLEYS
AS FORECASTED RH VALLEYS ABOVE 95% ARE LIKELY FOR MOST VALLEYS
BESIDES THOSE IN NE TRINITY COUNTY. ANOTHER FEATURE THAT COULD
LIMIT FROST FORMATION IS WINDS LASTING OVERNIGHT. OVER THE NEXT
24HRS, IT WILL BECOME MORE CLEAR ON THIS THREAT AS GROUND
OBSERVATIONS RECORD THE MOISTURE FLUX TO THE AREA.
THIS COMING WORK WEEK, THE TROUGH THAT WILL IMPACT THIS WEEKEND'S
WEATHER WILL MOVE EASTWARD OVER THE GREAT BASIN ALLOWING FOR AN
UPPER LEVEL RIDGE TO REBUILD INTO THE REGION. THIS REBUILDING WILL
SHOW A WARMING TREND BACK TO ABOVE NORMAL TEMPERATURES FOR INLAND
AREAS, DRY RIDGES, AND OVERCAST SKIES ALONG THE NORTH COAST.
TEMPERATURES IN THE 80S ARE LIKELY BY MIDWEEK AND COULD EVEN BREAK
90DEGF BY THE END OF THE COMING WEEK. DS
MARINE...AN INCOMING DRY COLD FRONT WILL CONTINUE TO CAUSE ENHANCED
STRONG TO GALE FORCE WINDS THROUGH THE WEEKEND. THESE WINDS WILL
STRENGTHEN THROUGH TODAY, WITH GUSTS TO 40 KTS. NEAR STORM FORCE
GUSTS WILL DEVELOP SOUTH OF CAPE MENDOCINO. STEEP AND HAZARDOUS
SHORT PERIOD SEAS OF 12 TO 15 FT ARE DEVELOPING AS A RESULT. IN
ADDITION TO VERY STEEP SHORT PERIOD SEAS, A MODERATE, VERY LONG
PERIOD WESTERLY SWELL WILL IMPACT THE WATERS AROUND SUNDAY WHILE
GALE CONDITIONS REMAIN IN THE OUTER WATERS AND AROUND CAPE
MENDOCINO. WINDS WILL GRADUALLY SUBSIDE EARLY NEXT WEEK WHILE THE
LONG PERIOD SWELL VERY SLOWLY WEAKENS.
FIRE WEATHER...CLOSE TO RECORD BREAKING ERCS EXIST FOR THE AREA AT
THIS TIME OF YEAR TODAY. AN INCOMING DRY COLD FRONT WILL ALSO CAUSE
AN UNSTABLE ATMOSPHERE LEADING TO STRONG WIND GUSTS FOR RIDGES AND
CHANNELED TERRAIN ALONG THE NNW FLOW. WINDS WILL TURN MORE EASTERLY
BY EARLY SUNDAY, FURTHER DRYING CONDITIONS AND PRODUCING POOR RH
RECOVERY AT HIGH ELEVATIONS. THAT SAID, THIS COLD FRONT PASSAGE WILL
CAUSE CONDITIONS TO BE MUCH MORE SEASONABLY COOL AND MOIST (HIGHS IN
70S AND RH AROUND 30 PERCENT). HOWEVER, THE LACK OF ANY RAIN CHANCES
AND RECENT DRYING WILL STILL SUPPORT NEAR RECORD BREAKING BURNING
INDEX VALUES FOR OCTOBER AROUND SATURDAY. ALL OF THESE FACTORS
TOGETHER SHOW THAT THERE IS THE POTENTIAL FOR MUCH ABOVE AVERAGE
FIRE ACTIVITY THROUGH THE WEEKEND.
BEACH HAZARDS...THE FIRST LONG PERIOD SWELL OF THE SEASON
ARRIVES THIS WEEKEND. THE WEST-NORTHWEST SWELL WILL ARRIVE TO
NORTHERN CALIFORNIA THIS EVENING WITH A PERIOD OVER 25 SECONDS.
SWELL WILL THEN BUILD THROUGH SUNDAY, PEAKING SUNDAY AFTERNOON AND
EVENING AT AROUND 5 FEET AT 19 SECONDS. THIS VERY LONG PERIOD
SWELL WILL RESULT IN A HEIGHTENED CHANCE FOR SNEAKER WAVES AND
RUN-UPS OF UNUSUAL SIZE THROUGH MONDAY EVENING. A BEACH HAZARD
STATEMENT HAS BEEN ISSUED FOR SUNDAY MORNING THROUGH MONDAY MIDDAY
AS A RESULT.
WHILE THE THREAT FOR SNEAKER WAVES WILL BE PERSISTENT THROUGHOUT
SUNDAY AND MONDAY, THE HIGHEST RISK IS EXPECTED DURING PERIODS OF
INCOMING TIDES. WITH HIGH TIDES ALONG THE CALIFORNIA COAST AT AROUND
11AM TO 1PM SUNDAY AND MONDAY ALONG N CA COAST. A POSITIVE TIDAL
ANOMALY IS YIELDING TIDES AROUND 1-1.5 FEET HIGHER THAN
PREDICTIONS ON TOP OF HIGHER THAN USUAL TIDES, ADDING TO THE
THREAT.
COASTAL FLOODING...A NEW MOON LUNAR CYCLE IS CAUSING HIGHER
THAN USUAL TIDES. A POSITIVE TIDAL ANOMALY OF 1-1.5 FEET WILL
YIELD HIGH TIDES THAT WILL BE NEAR OR EVEN REACH ADVISORY LEVELS
OF 8.8 FT FOR HUMBOLDT BAY SATURDAY, SUNDAY, AND MONDAY.
NORTH SPIT HIGH TIDE ESTIMATES: SATURDAY: 8.5 FT AT 12:03 P.M.;
SUNDAY: 8.8 FT AT 12:32 P.M.; MONDAY: 8.6 FT AT 1:01 P.M.
EKA WATCHES/WARNINGS/ADVISORIES
CA...
BEACH HAZARDS STATEMENT FROM LATE TONIGHT THROUGH MONDAY
AFTERNOON FOR CAZ101-103-104-109.
NORTHWEST CALIFORNIA COASTAL WATERS...
GALE WARNING UNTIL 4 AM PDT SUNDAY FOR PZZ450-455.
GALE WARNING UNTIL 2 AM PDT MONDAY FOR PZZ470-475.
NOTE: THE FULL FORECAST DISCUSSION IS NOW REGULARLY ISSUED BETWEEN
10 AM/PM AND 1 PM/AM. ADDITIONAL UPDATES WILL BE ISSUED AS NEEDED.
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