654
FXUS66 KEKA 180752
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
1252 AM PDT FRI JUL 18 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 TODAY 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
AFTER A BRIEF REPRIEVE IN THE COASTAL CLOUDINESS AT ACV AND CEC
TODAY, THE STRATUS QUICKLY RETURNED AND LIFR CONDITIONS HAVE
DEVELOPED ALONG MUCH OF THE COAST. THESE LOW CEILINGS WILL PERSIST
OVERNIGHT AND MAY CONTINUE TO DESCEND WITH LOWERING VISIBILITY AND
THE POTENTIAL FOR DRIZZLE AT THE COAST. ONCE AGAIN THE STRATUS WILL
PUSH INTO THE NEAR COASTAL VALLEY LOCATIONS A MAY ALSO BUILD NORTH
FROM SONOMA COUNTY INTO THE UKIAH AREA FOR A FEW HOURS IN THE EARLY
MORNING.
THERE IS POTENTIAL FOR A LITTLE MORE CLEARING NEAR THE COAST ON
FRIDAY AS NORTHERLY WINDS AT THE COAST INCREASE AND MIXING MAY
IMPROVE. GUIDANCE IS INDICATING DRY, OFFSHORE WINDS FROM SOUTHERN
OREGON HAVE THE POTENTIAL TO COMPLETELY MIX OUT THE CLOUDS NORTH OF
CAPE MENDOCINO DURING THE DAY AND INTO THE EARLY EVENING HOURS.
ELSEWHERE, VFR IS EXPECTED IN THE INTERIOR ONCE ANY EARLY MORNING
CLOUD COVER DISSIPATES. /RPA
MARINE
NORTHERLY WINDS ARE BEGINNING TO INCREASE OVER THE COASTAL WATERS AS
HIGH PRESSURE BUILDS BACK TOWARD THE COAST OVER THE EASTERN PACIFIC
OCEAN. THE PRESSURE GRADIENT WILL CONTINUE TO TIGHTEN INTO THE
WEEKEND WITH MODERATE TO STRONG NORTHERLY WINDS SATURDAY AND SUNDAY,
STRONGEST OVER THE OUTER WATERS ZONES. SMALL CRAFT ADVISORIES MAY BE
NEEDED FOR SOME ZONES OVER THE WEEKEND AS SEAS BUILD IN RESPONSE.
WINDS AND SEAS WILL SUBSIDE EARLY NEXT WEEK WITH ANOTHER TROUGH
DIVING SOUTH OVER THE COASTAL WATERS, PUSHING THE SURFACE HIGH
PRESSURE BACK FARTHER WEST. LIGHT WINDS AND LOW SEAS ARE ANTICIPATED
FOR MUCH OF THE WEEK. /RPA
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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