536
FXUS66 KEKA 030700
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
1200 AM PDT SAT OCT 3 2026
KEY MESSAGES
* UNSEASONABLY HOT TEMPERATURES WILL PEAK SATURDAY WITH CLOSE TO
RECORD BREAKING DAYTIME HIGHS. SUCH TEMPERATURES WILL GENERATE
MODERATE HEATRISK ACROSS THE INTERIOR THROUGH MID NEXT WEEK.
* SHALLOW, DIURNAL MARINE LAYER PERSISTING ALONG THE COAST THROUGH
THE WEEKEND.
* NEARLY 0% CHANCE OF WETTING RAIN FOR THE NEXT 10 DAYS.
SYNOPSIS
HIGH PRESSURE PEAKING THIS WEEKEND WILL CREATE
UNSEASONABLY HOT AND DRY CONDITIONS FOR THE INTERIOR. MORNING FOG
WILL BE MOST LIKELY ALONG THE NORTH COAST WITH POTENTIAL CLEARING
FOR THE AFTERNOON. WINDS WILL GENERALLY BE LIGHT.
DISCUSSION
AN UNSEASONABLY HIGH UPPER LEVEL RIDGE CONTINUES TO
BUILD OVER NW CALIFORNIA. THIS UPPER LEVEL RIDGE WILL FORCE A VERY
STABLE ATMOSPHERE WITH AFTERNOON COMPRESSIONAL HEATING DOWN AT THE
SURFACE. HEATING HAS A CHANCE (~50-60%) OF BREAKING THE RECORD AT
KUKI IN UKIAH WITH MANY OTHER INLAND VALLEYS REACHING TEMPERATURES IN
THE UPPER 90S TO TRIPLE DIGITS. IT SEEMS THE HOTTEST VALLEYS WILL BE
THOSE THAT ARE ORIENTATED NORTH TO SOUTH. THESE TEMPERATURES ARE
EXTREME AND IT IS RECOMMENDED TO TAKE EXTRA PRECAUTIONS TO PREVENT
HEAT BORNE ILLNESSES SUCH AS INCREASED SHADE AND HYDRATION,
ESPECIALLY FOR SENSITIVE DEMOGRAPHICS. MODERATE HEATRISK IS EXPECTED
AND A HEAT ADVISORY HAS BEEN ISSUED FOR VALLEYS IN LAKE AND INTERIOR
MENDOCINO COUNTIES.
OVER THE NEXT FEW NIGHTS, COLDER AIR WILL FLOW DOWN SLOPES BEFORE
SETTLING INTO VALLEYS. THIS WILL COOL DOWN TEMPERATURES AT VALLEY
LEVEL WHILE LEAVING THE MIDSLOPE AND UPPER RIDGES WARM OVERNIGHT.
RELATIVE HUMIDITY'S WILL REMAIN LOW AT THE HIGHER ELEVATIONS AS A
RESULT AS WELL. COASTAL AREAS, ESPECIALLY IN DEL NORTE AND N.
HUMBOLDT CAN EXPECT CONTINUED OVERCAST SKIES AND AREAS OF LIGHT
DRIZZLE.
LOOKING FURTHER AHEAD, HIGH PRESSURE WILL SLOWLY WEAKEN THROUGH
NEXT WEEK, THOUGH ABOVE AVERAGE INTERIOR TEMPERATURES ARE LIKELY TO
LINGER THROUGH WEDNESDAY. BOTH THE GEFS AND EPS GLOBAL ENSEMBLE
MODELS SHOW A VERY WEAK CUTOFF LOW IMPACTING THE AREA AROUND MONDAY.
AT MOST, THIS LOW WILL LIFT THE MARINE LAYER AND PROMOTE SOME
DRIZZLE. THERE IS MIXED CONFIDENCE, BUT ABOUT 50% OF MODELS SHOW
ANOTHER PEAK OF HIGHS NEAR 100 ON TUESDAY BEHIND THE LOW. OTHER THAN
WEAKENING HIGH PRESSURE, THERE IS NO IMPACTFUL WEATHER ON THE
HORIZON. THERE REMAINS A NEAR ZERO CHANCE OF WETTING PRECIPITATION
FOR AT LEAST THE NEXT 10 DAYS. LONG RANGE FORECAST SUGGEST THIS DRY
PATTERN IS MOST LIKELY TO PERSIST THROUGH AT LEAST THE SECOND WEEK
OF OCTOBER. /JHW & DS
AVIATION
COASTAL STRATUS HAS RETURNED TO THE NORTH COAST WITH
LIFR CONDITIONS EXPECTED THROUGH THE EARLY AFTERNOON (~21Z). DAYTIME
CONDITIONS SHOW POSSIBLE CLEARING FOR THE COAST WITH A 40% CHANCE OF
THE FOG BANK REMAINING OVER TERMINAL SPACES. NORTH WINDS ARE
EXPECTED FOR THE ENTIRE COASTLINE TOMORROW. MENDOCINO COASTAL
TERMINALS HAVE A HIGHER CHANCE (>=80%)OF REMAINING VFR TOMORROW.
EITHER WAY, LIFR IS EXPECTED TO RETURN SATURDAY EVENING (AROUND
02Z) AS A SHALLOW MARINE LAYER REMAINS IN PLACE. INLAND TERMINALS
ARE EXPECTED TO HAVE VFR WITH AFTERNOON, TERRAIN-DRIVEN,
UPSLOPE/UPVALLEY WINDS. GUSTS COULD BE STRONG NEAR ELEVATED
TERRAIN IN THE AFTERNOON DUE TO INTENSE SURFACE HEATING THIS
WEEKEND AS WELL. DS
MARINE
MODERATE TO STRONG WINDS WIND HAVE PERSISTED IN THE OUTER
WATERS WITH MUCH CALMER WINDS CLOSER TO SHORE. STEEP SHORT PERIOD
SEAS OVER 10 FEET WILL REMAIN IN THE OUTER WATERS WITH SOME STEEPER
SEAS AROUND 7 FEET AT 9 SECONDS BLEEDING INTO THE INNER WATERS.
BEYOND SHORT PERIOD SEAS, A VERY MINOR SOUTHWEST SWELL IS AUGMENTING
THE SEA STATE. WINDS WILL WEAKEN THROUGH THE WEEKEND AS HIGH
PRESSURE PUSHES EAST OF THE AREA. OUTER WATER GUSTS WILL MOST LIKELY
DROP BELOW 21 KTS BY SATURDAY AFTERNOON WITH SEAS ALSO DROPPING
BELOW 5 FEET. THESE MORE SUBDUED CONDITIONS WILL LIKELY PERSIST INTO
EARLY NEXT WEEK. /JHW
FIRE WEATHER
A BUILDING UPPER LEVEL RIDGE CONTINUE TO BUILD OVER
THE WEST. THIS WILL LEAD TO COMPRESSIONAL HEATING AND A STABLE
ENVIRONMENT. THE RESULTING WEATHER IS EXPECTED TO BE HOTTER AND
DRIER THROUGH THE WEEKEND, INCREASING FIRE DANGER. NEAR RECORD HIGH
TEMPERATURES FOR OCTOBER WILL AID IN ERC VALUES CRESTING BACK NEAR
THE 90TH PERCENTILE EARLY NEXT WEEK. THAT SAID, VERY WEAK TERRAIN
WINDS AND INCREASINGLY LONG NIGHTS WILL PREVENT BURNING INDEX VALUES
FROM REACHING ABOVE THE 70TH PERCENTILE. THESE VALUES IMPLY FIRE MAY
BE UNUSUALLY EASY TO IGNITE BUT SPREAD POTENTIAL IS ONLY MODERATE.
IT SHOULD BE KNOW THAT RIDGETOPS COULD EXPERIENCE ENHANCED WINDS
WITH GUSTS UP TO 15MPH DURING THE PEAK OF THE AFTERNOON. THERE IS
LITTLE CHANCE OF WEATHER INDUCED IGNITIONS. ENHANCED CONDITIONS WILL
PERSIST THROUGH NEXT WEEK. /JHW
EKA WATCHES/WARNINGS/ADVISORIES
CA...
HEAT ADVISORY FROM 11 AM TO 11 PM PDT SATURDAY FOR CAZ112-
113-118>120.
NORTHWEST CALIFORNIA COASTAL WATERS...
SMALL CRAFT ADVISORY UNTIL 9 AM PDT SATURDAY 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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