046
FXUS66 KEKA 091912
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
1212 PM PDT SAT AUG 9 2025
SYNOPSIS
HOT AND DRIER WEATHER CONDITIONS EXPECTED THROUGH
TUESDAY. MODERATE TO LOCALIZED MAJOR HEATRISK THIS WEEKEND AND
MONDAY. GUSTY OFFSHORE WINDS ARE EXPECTED OVER THE HIGHER TERRAIN IN
DEL NORTE COUNTY SATURDAY, WITH BREEZY OFFSHORE FLOW TONIGHT INTO
SUNDAY. A GRADUAL COOL DOWN IS EXPECTED BY MID TO LATE NEXT WEEK.
KEY MESSAGES
* HEAT PEAK THIS WEEKEND WITH MODERATE TO LOCALIZED MAJOR HEATRISK
ACROSS THE INTERIOR.
* HOTTER TEMPERATURES ACROSS THE INTERIOR VALLEYS WILL RESULT IN
MAJOR RISK OF HEAT-RELATED ILLNESS FOR ANYONE WITHOUT EFFECTIVE
COOLING AND/OR ADEQUATE HYDRATE.
* COASTAL AREAS WILL BE A BIT WARMER THIS WEEKEND, THOUGH PEAKS
TODAY WITH HIGHS FROM 65 TO 80 DEGREES IN MOST SPOTS.
* GUSTY OFFSHORE WINDS OVER THE HIGHER TERRAIN IN DEL NORTE COUNTY
THROUGH TONIGHT WITH SLIGHTLY WEAKER WINDS SUNDAY.
DISCUSSION
AN UPPER LEVEL RIDGE WILL CONTINUE TO AMPLIFY
SUBSTANTIALLY OVER OUR AREA DURING THE NEXT 24 HOURS. SKIES ARE
MOSTLY CLEAR ACROSS THE AREA DUE TO A LARGE SCALE SUBSIDENCE AND
LIGHT TO LOCALLY BREEZY OFFSHORE FLOW OVERNIGHT. GUSTY ENE WINDS
AROUND 25 TO 40 MPH OVER THE HIGHER TERRAIN IN DEL NORTE COUNTY
AND WINDIER RIDGES FARTHER NORTHERN PORTION OF HUMBOLDT COUNTY.
OFFSHORE WINDS WILL PERSIST THROUGH THE WEEKEND, BUT SHOULD
DIMINISH SLIGHTLY TONIGHT INTO SUNDAY.
THE LOW- LEVEL AIRMASS ACROSS NRN CA WILL CONTINUE TO WARM THROUGH
MONDAY (850 MB TEMPERATURES RANGING FROM 25-31C), AND WHEN COMBINED
WITH DAYTIME SUNSHINE WILL YIELD AFTERNOON TEMPERATURES FROM
MID/UPPER 90'S TO LOCALLY 110F. EXCEPT FOR BIG BAR, WHERE A HIGH OF
115F IS FORECAST FOR SUNDAY AND MONDAY. MODERATE TO LOCALIZED MAJOR
HEATRISK IS EXPECTED ACROSS THE INTERIOR THROUGH MONDAY. A HEAT
ADVISORY REMAIN IN EFFECT FOR SATURDAY AND SUNDAY FOR DEL NORTE
INTERIOR, NORTHERN HUMBOLDT INTERIOR, NORTHERN TRINITY AND SOUTHEAST
MENDOCINO INTERIOR DUE TO DUE TO LIMITED OVERNIGHT RELIEF MIN
TEMPERATURES IN THE MID/UPPER 60'S AND HIGHS OVER 100. FOR THESE
AREAS, THERE IS A MAJOR RISK OF HEAT- RELATED ILLNESS FOR ANYONE
WITHOUT EFFECTIVE COOLING AND/OR ADEQUATE HYDRATION. THE COASTAL
AREAS ARE ALSO EXPECTED TO WARM UP WITH HIGHS IN THE 70'S BEFORE THE
SEA BREEZES DEVELOP WITH ADJACENT COASTAL AREAS INTO THE 80'S TODAY.
THE MARINE LAYER IS EXPECTED TO RETURN AND SLIGHTLY COOL THE COASTAL
AREAS THIS EVENING THROUGH EARLY NEXT WEEK.
TUESDAY, THE RIDGE BREAK DOWN AND A SHORTWAVE WILL GRADUALLY SQUEEZE
DOWN THE COAST BRINGING A RETURN TO COOLER WEATHER AND ENHANCED
ONSHORE FLOW. HOWEVER, TEMPERATURES ARE EXPECTED TO REMAIN IN THE
UPPER 90'S TO 105 ACROSS THE HOTTEST VALLEYS, ESPECIALLY IN TRINITY
COUNTY.
ENSEMBLE CLUSTERS AND DETERMINISTIC MODEL GUIDANCE SHOWS AN UPPER
LEVEL TROUGH FROM THE NORTHEAST PACIFIC DRIVING SOUTHWARD ALONG
THE COAST ON WEDNESDAY AND SETTLING OVER THE AREA LATE NEXT WEEK.
AVIATION
OFFSHORE FLOW HAS ALLOWED FOR CLEAR SKIES AND VFR
CONDITIONS ALL ACROSS THE AREA, EXCEPT FOR THE MENDOCINO COAST WHERE
LOW STRATUS AND FOG AS BLANKETED SHORE. OTHERWISE, GUSTY NORTH WINDS
ALONG SHORE TODAY, ESPECIALLY NEAR CRESCENT CITY, WILL BE THE MAIN
CONCERNS WITH MARGINAL LOW LEVEL WIND SPEED POSSIBLE DUE TO THE
SPEED DIFFERENCES. LOW CLOUDS AND STRATUS MAY INCH UP THE COAST
OVERNIGHT FROM SOUTH TO NORTH. SHOULD THIS OCCUR, 40% CHANCE, AT
LEAST A SHORT PERIOD OF IFR OR EVEN LIFR CONDITIONS SHOULD BE
EXPECTED FOR COASTAL TERMINALS, THOUGH STRONG CLEARING IS MOST
LIKELY EARLY TOMORROW MORNING. /JHW
MARINE
STRONG TO GALE FORCE WINDS CONTINUE IN THE NORTHERN
OUTER WATERS TODAY WITH STEEP SHORT PERIOD SEAS FILLING IN
THROUGHOUT THE NORTHERN INNER WATERS. STRONGER WINDS HAVE SHUNTED
FURTHER OFFSHORE IN SOUTHERN WATERS, THOUGH STEEP SHORT PERIOD SEAS
HAVE BEEN SLOW TO DIMINISH TODAY. A SOUTHERLY IND REVERSAL HAS JUST
STARTED TO MANIFEST RIGHT ALONG THE MENDOCINO COAST.
NORTHERLIES WILL CONTINUE TO PUSH FURTHER OUT OF THE WATERS OVER THE
NEXT 24 HOURS, WITH GENTLE TO EVEN MODERATE SOUTHERLY WINDS REVERSING
WITHIN THE INNER WATERS. THESE SOUTHERLY WINDS MAY PROMOTE LOW
MARINE FOG CLOSE TO SHORE. SHORT PERIOD SEAS WILL GENERALLY FALL
BELOW 6 FEET BY SUNDAY AFTERNOON WITH CALMER CONDITIONS INTO EARLY
NEXT WEEK. THAT SAID, MINOR MID PERIOD NORTHWEST AND SOUTHWEST
SWELLS WILL INTERACT TO CONFUSE THE SEA STATE A BIT, ESPECIALLY
SUNDAY EVENING AND EARLY MONDAY. STRONGER NORTHERLY WIND WILL RETURN
AROUND MID NEXT WEEK. /JHW
FIRE WEATHER
HOT AND DRIER WEATHER CONDITIONS ARE EXPECTED
TODAY THROUGH TUESDAY. VERY DRY DAYTIME RH'S VALUES IN THE LOW
20'S AND TEENS PERCENT ARE EXPECTED. DRY OFFSHORE FLOW (E-NE
WINDS) AND ABOVE NORMAL TEMPERATURES ARE FORECAST TO PERSIST
THROUGH THIS WEEKEND. GUSTS FROM 20 TO 30 MPH ARE EXPECTED
THROUGH TONIGHT OVER THE HIGHER TERRAIN AREAS OF DEL NORTE AND
WINDIER RIDGES OF FAR NORTHERN HUMBOLDT. THE OFFSHORE WINDS SHOULD
DIMINISH THIS EVENING INTO SUNDAY, BUT THE DOME OF WARM/DRY AIR
WILL LIKELY STICK AROUND THROUGH EARLY NEXT WEEK. WINDS ARE
EXPECTED TO BE LIGHT DURING THE DAY, YET WESTERLY UP VALLEY WINDS
MAY BECOME BREEZY EACH AFTERNOON AND EVENING. DRY WEATHER WILL
CONTINUE NEXT WEEK, BUT WITH A GRADUAL COOLING TREND AND IMPROVED
RH RECOVERIES BY MID TO LATE NEXT WEEK. /ZVS
EKA WATCHES/WARNINGS/ADVISORIES
CA...
HEAT ADVISORY UNTIL 10 PM PDT THIS EVENING FOR CAZ102-105-
107-110-113.
HEAT ADVISORY FROM 9 AM SUNDAY TO 1 AM PDT MONDAY FOR
CAZ102-105-107-113.
NORTHWEST CALIFORNIA COASTAL WATERS...
SMALL CRAFT ADVISORY UNTIL 11 AM PDT SUNDAY FOR PZZ450-475.
GALE WARNING UNTIL 11 PM PDT THIS EVENING FOR PZZ470.
HAZARDOUS SEAS WARNING FROM 11 PM THIS EVENING TO 11 AM PDT
SUNDAY FOR PZZ470.
NOTE: THE FULL FORECAST DISCUSSION IS NOW REGULARLY ISSUED BETWEEN
10 AM/PM AND 1 PM/AM. ADDITIONAL UPDATES WILL BE ISSUED AS NEEDED.
VISIT US AT HTTPS://WWW.WEATHER.GOV/EUREKA
FOLLOW US ON FACEBOOK AND TWITTER AT:
HTTPS://WWW.FACEBOOK.COM/NWSEUREKA
HTTPS://WWW.TWITTER.COM/NWSEUREKA
FOR FORECAST ZONE INFORMATION
SEE THE FORECAST ZONE MAP ONLINE:
HTTPS://WWW.WEATHER.GOV/IMAGES/EKA/ZONEMAP.PNG
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page