405
FXUS66 KEKA 070740
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
1240 AM PDT THU MAY 7 2026
SYNOPSIS
WARM TEMPERATURES PERSIST THROUGH EARLY NEXT WEEK FOR
THE INTERIOR. OVERCAST CONDITIONS AT THE COAST ARE STUBBORN,
KEEPING TEMPERATURES NEAR NORMAL. INTERIOR TEMPERATURES COULD
BREAK 90F FOR INTERIOR VALLEYS MONDAY AND TUESDAY.
KEY MESSAGES: ABOVE NORMAL TEMPERATURES FOR THE INTERIOR THROUGH
EARLY NEXT WEEK.
MINOR TO MODERATE HEAT RISK IS POSSIBLE ON MONDAY AND TUESDAY IN
MENDOCINO, LAKE AND TRINITY COUNTIES.
COASTAL OVERCAST CONDITIONS TO CONTINUE THROUGH THE END OF THE WEEK.
DISCUSSION...SHORT TERM
A BROAD H5 RIDGE OF HIGH PRESSURE IS
BEGINNING TO DOMINATE OVER THE PACIFIC NORTHWEST THROUGH THE END OF
THE WEEK. WHILE THIS HIGH PRESSURE IS NOT OVERLY ANOMALOUS, 8-12DAM
ABOVE NORMAL, IT WILL LEAD TO A WARMING TREND THROUGH EARLY NEXT
WEEK. MOST OF THIS WARMING WILL BEGIN THIS WEEKEND FOR THE INTERIOR.
CLEAR SKIES AND CONTINUOUSLY SUBSIDING AIR WILL CAUSE INCREASING
DAYTIME TEMPERATURES, ESPECIALLY SATURDAY THROUGH TUESDAY. THIS
HEATING WILL FORCE GUSTY, UP-VALLEY WINDS EACH AFTERNOON THROUGH
TUESDAY. NIGHTTIME WINDS WILL BE CALMER AND HAVE DOWNSLOPE OR
DOWNVALLEY FLOW AS COOL AIR DRAINS INTO LOWER ELEVATIONS. THIS WIND
PATTERN WILL FORCE COOLER AIR TO SETTLE IN THE VALLEYS WHILE
RIDGETOPS REMAIN WARM LEADING TO THERMAL BELTS DEVELOPMENT.
NIGHTTIME TEMPERATURE DIFFERENCES BETWEEN RIDGETOPS AND VALLEYS
COULD BE AS STRONG AS A 15F DIFFERENCE BY NEXT WEEK.
WHILE CLEAR SKIES DOMINATE INTERIOR AREAS, COASTAL COMMUNITIES WILL
REMAIN UNDER A WIDESPREAD LAYER OF OVERCAST CONDITIONS THROUGH THE
END OF THE WEEK. HIGH PRESSURE WILL COMPRESS THE MARINE LAYER
LEADING TO STUBBORN MARINE STRATUS. THIS STRATUS DECREASES THE
IMPACT FROM RADIATIONAL DAYTIME HEATING AND NIGHTTIME COOLING
KEEPING TEMPERATURES MILD. HREF DATA SHOWS PROBABILITIES OF LOW-
CLOUD COVERAGE CLOSE TO ~90% OVERNIGHT FOR COASTAL AREAS. DAYTIME
PROBABILITIES DECREASE TO ~40%, ESPECIALLY FOR COASTAL AREAS NOT
AROUND HUMBOLDT BAY. THIS COULD LEAD TO PERIODIC CLEARING FOR THOSE
AREAS IN THE AFTERNOON.
LONG TERM...BOTH GFS AND ECMWF ENSEMBLE DATA SHOWS RELATIVELY DRY
CONDITIONS THROUGH THE MIDDLE OF NEXT WEEK. THE UPPER LEVEL RIDGE IS
FORECASTED TO BREAKDOWN ON WEDNESDAY AS A POSSIBLE FRONTAL SYSTEM
IMPACTS THE AREA. CPC 6-10DAY OUTLOOKS COMPARED TO 8-14DAY OUTLOOKS
SHOW SLIGHTLY COOLER TEMPERATURES AND A HIGHER CHANCE OF
PRECIPITATION. SO WHILE IT MIGHT BE WARM THIS WEEKEND AND EARLY NEXT
WEEK, THIS WARM SPELL IS NOT FORECASTED TO LAST LONG.
AVIATION
STRATUS IS IN PLACE ALONG THE COAST AND 10 TO 20 MILES
INLAND. THIS IS EXPECTED TO EXPAND INLAND AND LOWER SOME MORE
TOWARDS MORNING. GENERALLY THESE ARE EXPECTED TO BE IFR TO MVFR,
ALTHOUGH THERE MAY BE A FEW POCKETS OF LIFR. THURSDAY EARLY
AFTERNOON THERE MAY BE A FEW BREAKS IN THE STRATUS AT KACV AND
KCEC, BUT THE BOTH THE REFS AND THE HREF SHOW ONLY AN HOUR OR TWO
OF POSSIBLE VFR CONDITIONS. SO KEPT MVFR CONDITIONS IN PLACE. THE
PROBABILITY OF CLEARING INCREASES SIGNIFICANTLY FRIDAY AFTERNOON.
MKK
MARINE
GENTLE TO MODERATE NORTHERLY BREEZES CONTINUE THROUGH
THE DAY THURSDAY ACROSS THE WATERS. THE WAVES REMAIN A COMBINATION
OF AN 8 AND 13 SECOND SWELLS. THESE ARE AROUND 3 AND 5 FEET
RESPECTIVELY. THESE ARE EXPECTED TO CONTINUE THROUGH THURSDAY,
ALTHOUGH THE PERIODS ARE EXPECTED TO GET CLOSER. THE SHORT PERIOD
WIND DRIVEN WAVES ARE ALSO EXPECTED TO START TO INCREASE. SO HAVE
COMBINED THE TWO MID PERIOD SWELLS SO THE SHORT PERIOD WAVES WILL
BE VISIBLE IN THE CWF.
THURSDAY NIGHT AND FRIDAY A WEAK FRONTAL BOUNDARY APPROACHING THE
AREA WILL DIMINISH THE WINDS NORTH OF CAPE MENDOCINO. FARTHER
SOUTH NORTHERLY WINDS STARTS TO INCREASE BY FRIDAY AFTERNOON. THE
HREF IS SHOWING AN 85 PERCENT CHANCE OF A FAIRLY LARGE AREA SOUTH
OF CAPE MENDOCINO EXCEEDING 21 KT AT 5PM ON FRIDAY. SATURDAY
THESE STRONGER WINDS ARE EXPECTED TO EXPAND FARTHER NORTH WITH 15
TO 20 KT ACROSS MUCH OF THE AREA NORTH OF CAPE MENDOCINO. THIS IS
EXPECTED TO BUILD THE SHORT PERIOD WIND DRIVEN WAVES TO AROUND 4
TO 7 FEET. STRONGER WINDS ARE EXPECTED ON SUNDAY WITH NEAR GALE
TO GALE FORCE GUSTS POSSIBLE BY SUNDAY AFTERNOON. BREEZY NORTHERLY
WINDS ARE EXPECTED TO CONTINUE INTO EARLY NEXT WEEK. MKK
PREV DISCUSSION
/ISSUED 308 PM PDT WED MAY 6 2026/
SYNOPSIS...WEAK HIGH PRESSURE BUILDING INTO THE AREA WILL GRADUALLY
WARM INLAND TEMPERATURES THROUGH THURSDAY. CLOSER TO THE COAST
WIDESPREAD LOW CLOUDS WILL LINGER KEEPING TEMPERATURES COOLER.
FRIDAY WILL SEE SLIGHTLY COOLER TEMPERATURES AND MORE CLOUDS. FOR
THE WEEKEND AND INTO EARLY NEXT HIGHS ARE EXPECTED TO WARM EACH DAY
WITH MANY INLAND AREAS SEEING THE 90S BY MONDAY.
KEY MESSAGES: NEAR TO ABOVE NORMAL INLAND TEMPERATURES THURSDAY
WITH SOME COOLING FRIDAY.
BREEZY NORTH WINDS THIS WEEKEND WITH WELL ABOVE NORMAL TEMPERATURES
INLAND.
MINOR TO MODERATE HEAT RISK IS POSSIBLE ON MONDAY IN MENDOCINO, LAKE
AND TRINITY COUNTIES.
DISCUSSION...HIGH PRESSURE IS BUILDING OVER THE AREA IN THE WAKE
OF A DEPARTING LOW. THIS WILL BRING CLEARING SKIES AND WARMING
TEMPERATURES FOR MUCH OF THE INTERIOR. STRATUS HAS RETREATED TO
THE USUAL COASTAL AREAS OF HUMBOLDT, DEL NORTE AND MENDOCINO
COUNTIES AND WILL RETURN WITH LESS COVERAGE OVERNIGHT INTO
THURSDAY MORNING THAN PREVIOUS PAST FEW DAYS. THOUGH HREF DOES
HAVE A LESS VIGOROUS LOW LEVEL CLOUD COVER THURSDAY AFTERNOON,
STRATUS IS EXPECTED TO STRADDLE THE COASTLINE AND WILL LINGER
AROUND HUMBOLDT BAY AND THE COASTLINE UP TO THE OREGON BORDER.
THURSDAY NIGHT INTO FRIDAY A WEAK FRONT WILL BRING SOME MID LEVEL
CLOUDS AND COOLER TEMPERATURES TO TRINITY COUNTY. THIS MAY BRING
SOME DRIZZLE TO THE COAST, BUT AT THIS POINT NO REAL RAIN IS
EXPECTED. FRIDAY NIGHT INTO SATURDAY NORTHERLY WINDS ARE EXPECTED TO
INCREASE. OFFSHORE FLOW IS EXPECTED OVERNIGHT WITH BREEZY AFTERNOON
WINDS. INLAND AREAS ARE EXPECTED TO WARM AGAIN ON SATURDAY AND WITH
MOSTLY CLEAR SKIES AREAS CLOSER TO THE COAST WILL LIKELY WARM UP
TOO. THE BREEZY NORTHERLY WINDS TYPICALLY KEEP THE IMMEDIATE COAST
IN THE LOW 60S. THE WARMING TREND IS EXPECTED TO CONTINUE INTO EARLY
NEXT WEEK. AT THIS POINT THE FIRST DAY EXPECTED TO SEE MODERATE HEAT
RISK IN THE FAR INLAND AREAS IS MONDAY. HOWEVER, THERE IS SOME
POTENTIAL AN UPPER LOW COULD DEVELOP OFF THE COAST WEAKEN THE WIND
FLOW ALLOWING CLOUDS AND MARINE AIR CREEP INTO THE COASTAL COUNTIES
LIMITING THE HEATING POTENTIAL. MKK/EYS
AVIATION...THE MARINE LAYER REMAINS DEEP AND EMBEDDED ALONG THE
COAST AND FARTHER INLAND. THE MVFR CEILINGS FROM THIS LAYER WILL
ONCE AGAIN LOWER WITH OVERNIGHT COOLING, WITH HIGH CONFIDENCE FOR
IFR LEVELS. WITH BUILDING HIGH PRESSURE, AND ADDITIONAL
COMPRESSIONAL EFFECTS, LIFR LEVELS ARE POSSIBLE. GUIDANCE IS
TRENDING WITH HIGHER PROBABILITIES FOR THIS SCENARIO. PROBABILITIES
FOR LIFR ARE AT THIS TIME 20-30%, BUT MOS GUIDANCE IS LATCHING ON TO
LOWER CEILINGS.
MARINE...NORTHERLY WINDS INCREASE SOME TODAY, TO AROUND 15-17 KTS,
MAINLY IN THE SOUTHERN WATERS AROUND THE CAPE. SIMILAR CONDITIONS
WILL CONTINUE THURSDAY, WITH SHORT PERIOD SEAS OF 3 TO 5 FEET AND
SOME SMALL MID PERIOD SWELLS. THURSDAY NIGHT INTO FRIDAY A WEAK
FRONT APPROACHING THE AREA IS EXPECTED TO BRING LIGHTER WINDS
NORTH OF CAPE MENDOCINO. ONLY AROUND 5 TO 10 KT AND THESE MAY
BRIEFLY BECOME WEST OR SOUTHWEST. FARTHER SOUTH THE WINDS ARE
EXPECTED TO INCREASE TO AROUND 15 TO 20 KT. BEHIND THE FRONT ON
THE WEEKEND WINDS ARE EXPECTED TO INCREASE TO NEAR GALE OR GALE
FORCE AS HIGH PRESSURE BUILDS IN AGAIN. THERE IS EXPECTED TO BE A
FAIRLY SMALL NORTHWEST SWELL THROUGH MUCH OF THE PERIOD. FRIDAY
NIGHT AND SATURDAY BEHIND THE WEAK FRONT THE SWELL MAY INCREASE
SLIGHTLY WITH PERIODS JUMPING UP TO AROUND 15 SECONDS, BUT HEIGHTS
REMAIN AROUND 3 OR 4 FEET. MKK/JJW
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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