120
FXUS66 KEKA 172024
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
124 PM PDT THU JUL 17 2025
SYNOPSIS
CONDITIONS WILL REMAIN HOT AND DRY INLAND, WHILE A
DEEPENED AND A RELATIVELY PERSISTENT MARINE LAYER KEEPS
TEMPERATURES COOLER ALONG SOME PORTIONS OF THE IMMEDIATE COAST.
DISCUSSION
UPPER TROUGHING TO THE NORTH HAS CONTINUED TO SUPPRESS
INLAND TEMPERATURES FROM HOTTER VALUES. A COASTAL SHORTWAVE IS
MAINTAINING A DEEP MARINE LAYER. A MODERATE TO STRONG INVERSION
COMBINED WITH TRANSIENT COASTAL WIND EDDIES ARE ALSO CONTRIBUTING TO
PERSISTENT DIURNAL COASTAL STRATUS. MODELS CURRENTLY SHOW A BETTER
SHOT OF CLEARING AND MORE COASTAL SUNSHINE ON SATURDAY, BUT THE
INVERSION STILL LOOKS TO BE ON THE STRONG SIDE. CONDITIONS ARE ALSO
FAVORABLE FOR OVERNIGHT LIGHT COASTAL DRIZZLE. THERE IS A VERY
SLIGHT CHANCE (LESS THAN 5%) FOR DRY THUNDERSTORMS IN FAR
NORTHEAST TRINITY COUNTY THURSDAY AFTERNOON. MODEL SOUNDINGS SHOW
VERY LIMITED TO NO ELEVATED INSTABILITY AND AVAILABLE MOISTURE,
WITH A GOOD AMOUNT OF CIN.
THE TROUGH WILL SUBTLY GIVE WAY TO THE DOMINANT FOUR CORNERS
REGION HIGH FRIDAY AND SATURDAY, ALLOWING FOR A SLIGHT UPTICK IN
SOME OF THE INLAND VALLEYS. THIS WILL INTRODUCE SOME ISOLATED
MODERATE HEATRISK. THE WARMING WILL PROVE TO BE VERY SHORT LIVED
AS THE TROUGH REESTABLISHES ITS DOMINANCE WITH A DEEPENING
PROGRESSION DOWN THE PACIFIC NORTHWEST AND INTO NORTHERN CA.
INLAND TEMPERATURES WILL DROP BY UP TO 10 DEGREES BY MONDAY. THE
COOLING INFLUENCE OF THE TROUGH WILL LIKELY LAST MOST OF NEXT WEEK
BEFORE THE FOUR CORNERS HIGH ATTEMPTS TO EXPAND. CLUSTERS
IDENTIFY THE POTENTIAL FOR MORE TROUGHING HOWEVER. JJW
AVIATION
(18Z TAFS) COASTAL CLOUDS ARE WELL ENTRENCHED WITH
LITTLE CLEARING EXPECTED OVER THE NEXT 24 HOURS OR SO AS A STRONG
INVERSION REMAINS IN PLACE OVER THE MARINE LAYER. LIFR TO IFR WILL
LIKELY PERSIST AT COASTAL TERMINALS THROUGH THURSDAY. WINDS WILL
REMAIN LIGHT AT THE COAST. THE WIND DIRECTION IS THE MAIN FORECAST
CHALLENGE WITH STRONG COASTAL EDDIES EVIDENT ON SATELLITE.
NORTHERLIES WINDS ARE EXPECTED TO REFORM ON FRIDAY, POSSIBLY LEADING
TO AN IMPROVEMENT IN CATEGORIES AS COASTAL STRATUS GETS MIXED OUT.
FARTHER INLAND, VFR CONDITIONS ARE LIKELY FOR INTERIOR AREAS ON
THURSDAY WITH ONLY A 30% CHANCE OF CLOUDS REENTERING THE RUSSIAN
RIVER VALLEY ALL THE WAY TO KUKI TONIGHT INTO FRIDAY MORNING.
MARINE
LIGHT WINDS AND LOW COMBINED SEAS ARE EXPECTED TODAY WITH
THE THERMAL TROUGH LOCATED OFF THE NORTHWEST CALIFORNIA COAST. ON
FRIDAY INTO THIS WEEKEND, AS HIGH PRESSURE RE-BUILDS OVER THE
EASTERN PACIFIC OCEAN, THE PRESSURE GRADIENT SHOULD TIGHTEN OVER THE
COASTAL WATERS ALLOWING NORTHERLIES TO STRENGTHEN AGAIN. MODERATE TO
STRONG NORTHERLIES AND STEEP SEAS DUE TO WIND WAVES ARE LIKELY OVER
THE WEEKEND WITH SMALL CRAFT ADVISORIES POSSIBLE, MOST LIKELY IN THE
OUTER WATERS. /RPA
FIRE WEATHER
CONDITIONS WILL REMAIN HOT AND DRY INTO THE
WEEKEND. A DEEP MARINE LAYER AND ONSHORE WINDS WILL CONTINUE TO
MAINTAIN MARINE INFLUENCE FARTHER INLAND FROM THE COAST, WITH SOME
COASTAL DRIZZLE. THERE IS A 5% OR LESS CHANCE FOR DRY THUNDERSTORMS
WITH GUSTY OUTFLOW WINDS OVER FAR NORTHEAST TRINITY COUNTY MOUNTAINS
THURSDAY AFTERNOON AND EVENING. ANYTHING THAT MANAGES TO FORM MAY
REMAIN IN SISKIYOU COUNTY. SOUTH TO SOUTHWEST WINDS ARE BREEZY IN
LAKE AND SOUTHERN MENDOCINO COUNTY THURSDAY AFTERNOON WITH A WEAK
SHORTWAVE TROUGH ALONG THE COAST. MINIMUM RH VALUES WILL DROP TO
THE MID TO LOW 20S THURSDAY, BUT OVERNIGHT RECOVERIES WILL BE
VERY STRONG, INTO THE UPPER 60S TO 70S. INLAND TEMPERATURES WILL
TREND MUCH COOLER, UP TO 10 DEGREES, SUNDAY AND INTO NEXT WEEK
WITH A DEEPENING TROUGH TO THE NORTH. THIS FEATURE WILL INCREASE
THE PRESSURE GRADIENT, STRENGTHENING THE WESTERLY WINDS IN
RESPONSE, PARTICULARLY SOUTH IN LAKE AND SOUTHERN MENDOCINO
COUNTY. 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.
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