845
FXUS66 KEKA 112105
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
205 PM PDT MON AUG 11 2025
SYNOPSIS
HOT AND DRIER WEATHER CONDITIONS CONTINUE. INLAND
HIGH TEMPERATURES DROP A FEW DEGREES TUESDAY BEFORE BEGINNING A
LASTING COOLING TREND ON WEDNESDAY. COASTAL STRATUS WILL CONTINUE
TO HAVE A FAIRLY DOMINANT PRESENCE, SUPPRESSING DAYTIME HIGHS FOR
SOME ON THE COAST.
DISCUSSION
THE SUNSHINE MADE AN APPEARANCE TO THE IMMEDIATE COAST
EARLY MONDAY, BUT SOUTHERLY FLOW QUICKLY USHERED THE MARINE STRATUS
BACK ON LAND INTO THE AFTERNOON. THUS, THE COASTAL TEMPERATURES
REMAIN COMFORTABLE BUT COOLER THAN THE PREVIOUS SUNNIER DAYS.
EXPECTING A SIMILAR EVOLUTION OF THE COASTAL STRATUS ON TUESDAY.
INTERIOR TEMPERATURES ARE HOT AGAIN MONDAY AFTERNOON, AND A HEAT
ADVISORY REMAINS IN EFFECT THROUGH MONDAY EVENING FOR A SMALL
PORTION OF FAR INTERIOR HUMBOLDT AND MAINLY TRINITY COUNTY.
TROUGHING WILL THEN BEGIN TO DEVELOP NORTH ON WEDNESDAY. THE
TROUGH WILL THEN STRENGTHEN AND ESTABLISH MORE SUBSTANTIAL
INFLUENCE LATE WEEK AND LIKELY THROUGH THE WEEKEND. THIS WILL ACT
TO GRADUALLY DRIVE DAYTIMES HIGHS DOWNWARD, EVENTUALLY TO BELOW
CLIMATOLOGICAL NORMS.
A SUBTLE PULSE OF MIDLEVEL MOISTURE WILL BE DRIVEN THROUGH LATE
TUESDAY AS THE HIGH WEAKENS AND DRIFTS FARTHER SOUTH, ENHANCING SW
FLOW AROUND IT. SOME CONVECTIVE ALLOWING MODELS DEVELOP SOME LIGHT
SHOWERS PUSHING IN FROM THE SW LATE TUESDAY THROUGH EARLY
WEDNESDAY AFTERNOON. INSTABILITY AND FORCING LOOK VERY LIMITED,
BUT THIS SETUP CAN PRODUCE UNEXPECTED, POORLY MODELED NOCTURNAL
THUNDERSTORMS. CHANCES ARE CURRENTLY VERY SMALL THROUGH SOUTH
MENDOCINO, LAKE AND TRINITY COUNTIES (LESS THAN 5%), BUT THE
LATEST MODEL RUNS WILL BE WATCHED CAREFULLY FOR ANY CHANGES. THE
TROUGH WILL ALSO BRING AN ENHANCED ONSHORE WINDS AND A DEEPENING
MARINE LAYER WITH MORE PERSISTENT COASTAL STRATUS. THE TROUGH WILL
DIG FARTHER SOUTH INTO NORTHERN CALIFORNIA THIS WEEKEND, AND
THOUGH UNLIKELY, SOME OF THE WETTEST ENSEMBLE MEMBERS DO SHOW SOME
POTENTIAL FOR VERY LIGHT RAINFALL FOR THE NORTHERN FORECAST AREA.
CURRENTLY, AT LEAST ABUNDANT LIGHT DRIZZLE IS FORECAST. JJW
AVIATION
STRATUS IS BEGINNING TO EVAPORATE AWAY AT COASTAL
TERMINALS AS DAYTIME MIXING TAKES EFFECT. CONFIDENCE IS MILD ON
HOW MUCH CLEARING WILL REMAIN THROUGH THE DAY, YET VFR CATEGORIES
ARE EXPECTED THROUGH THE 00Z HOUR. LIGHT WINDS EXPECTED TODAY
ACROSS ALL TERMINAL SPACES WITH COASTAL TERMINALS EXPECTED TO HAVE
VARIABLE DIRECTIONS AS EDDIES SPIN PERSIST. STRATUS AND POTENTIAL
FOG WITH VISIBILITIES UNDER 1/2SM ARE POSSIBLE WITH OVER A 70%
PROBABILITY OF LIFR RETURNING OVERNIGHT ALONG COASTAL TERMINALS.
INLAND, VFR IS EXPECTED WITH CALM WINDS TONIGHT. HEIGHT DENSITY
ISSUES CONTINUE TO BE POSSIBLE AS INLAND TEMPERATURES RISE TO OVER
TRIPLE DIGITS MONDAY AND TUESDAY.
MARINE
NORTHERLY WINDS CONTINUE TO MOVE FURTHER OFFSHORE
TONIGHT AS A SOUTHERLY WIND SURGE FILLS INTO THE COAST,
ACCOMPANIED WITH AREAS OF DENSE FOG LEADING TO VISIBILITIES
<1/2NM. OTHER THAN THE SLIGHTER MILDER NORTHERLY WIND WAVES, TWO
LONG PERIOD SWELLS HAVE BEGUN TO FILL IN EARLY THIS MORNING, ONE
FROM THE SOUTH-SOUTHWEST (3FT@17S) AND ANOTHER FROM THE NORTHWEST
(3FT@17S). THESE SWELLS HAVE THE POTENTIAL TO CREATE SQUARE/CROSS
WAVE PATTERNS DUE TO THE PERPENDICULAR WAVE DIRECTIONS CREATING
POSSIBLE GRID-LIKE PATTERNS. CONDITIONS REMAIN MILD EARLY THIS
COMING WEEK WITH BREEZY NORTHERLIES LIKELY TO RETURN BY
WEDNESDAY/THURSDAY.
FIRE WEATHER
A SUBTLE PULSE OF MIDLEVEL MOISTURE WILL BE
DRIVEN THROUGH LATE TUESDAY AS THE HIGH WEAKENS AND DRIFTS FARTHER
SOUTH, ENHANCING SW FLOW AROUND IT. SOME CONVECTIVE ALLOWING
MODELS DEVELOP SOME LIGHT SHOWERS LATE TUESDAY THROUGH EARLY
WEDNESDAY AFTERNOON. INSTABILITY AND FORCING LOOK VERY LIMITED,
BUT THIS SETUP CAN PRODUCE UNEXPECTED, POORLY MODELED NOCTURNAL
THUNDERSTORMS. CHANCES ARE CURRENTLY VERY SMALL THROUGH SOUTH
MENDOCINO, LAKE AND TRINITY COUNTIES (LESS THAN 5%), BUT THE
LATEST MODEL RUNS WILL BE WATCHED CAREFULLY FOR ANY CHANGES.
SOUNDINGS ARE VERY DRY, SO LITTLE TO NO PRECIPITATION WOULD FALL
WITH ANY CONVECTIVE DEVELOPMENT.
HOT AND DRIER WEATHER CONDITIONS CONTINUE. INLAND HIGH TEMPERATURES
DROP A FEW DEGREES TUESDAY BEFORE BEGINNING A LASTING COOLING
TREND ON WEDNESDAY. THE COOLING TREND WILL CONTINUE LATE THIS WEEK
AND LIKELY THROUGH THE WEEKEND WHEN DAYTIME HIGHS ARE CURRENTLY
FORECAST TO DROP BELOW CLIMATOLOGICAL NORMS. WINDS ARE EXPECTED
TO BE LIGHT DURING THE DAY, YET WESTERLY UP VALLEY WINDS MAY
BECOME BREEZY EACH AFTERNOON AND EVENING, PARTICULARLY IN LAKE AND
SOUTHERN MENDOCINO COUNTIES. ON THURSDAY, ELEVATED FIRE WEATHER
THREAT SHOULD BE POSSIBLE WITH ENHANCED ONSHORE WINDS AND LOW
DAYTIME RH IN THE TEENS AND 20'S, ESPECIALLY IN LAKE COUNTY. JJW
BEACH HAZARDS
BUOYS ARE PICKING UP ON A LONG PERIOD SOUTHERLY
SWELL. THE SMALL SWELL IS MIXING IN WITH SHORTER PERIOD SURF ON
SOUTH TO SOUTHWEST FACING BEACHES, BUT MAY STILL POSE A RISK FOR
SNEAKER WAVES. 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!
EKA WATCHES/WARNINGS/ADVISORIES
CA...
HEAT ADVISORY UNTIL 11 PM PDT THIS EVENING FOR CAZ105-107.
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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