959
FXUS66 KEKA 092044
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
144 PM PDT MON JUN 9 2025
SYNOPSIS
ISOLATED THUNDERSTORM THREAT FOR TRINITY, DEL NORTE,
AND NE MENDOCINO COUNTY CONTINUES THIS AFTERNOON INTO THE
EVENING. WARM TEMPERATURES CONTINUE TODAY, HOWEVER, A COOLING
TREND WILL KEEP TEMPERATURES COOLING STEADILY THROUGH THE WEEK.
KEY MESSAGES
* ISOLATED AFTERNOON AND EARLY THUNDERSTORMS IN THE INTERIOR,
PRIMARILY TRINITY COUNTY, TODAY AND TUESDAY. CLOUD-TO-GROUND
LIGHTNING STRIKES AND GUSTY ERRATIC FLOW WINDS POSSIBLE.
* INTERIOR HEAT RISK DIMINISHING AND BECOMING LOW ON WEDNESDAY.
HIGH TEMPERATURES GENERALLY DECREASING EACH DAY THIS WEEK ALONG
WITH COOLER OVERNIGHT LOW TEMPERATURES LATE THIS WEEK.
* GUSTIER AFTERNOON AND EVENING WESTERLY AND NORTHWESTERLY
BREEZES EXPECTED IN THE INTERIOR MID TO LATE WEEK.
* GUSTIER NORTHERLIES FOR COASTAL AREAS MID TO LATE WEEK.
DISCUSSION
A RIDGE THE THE SOUTH AND AN ANOMALOUSLY HIGH RIDGE TO THE NORTH
ARE SANDWICHING (FOR LACK OF BETTER TERMS) NW CALIFORNIA ALLOWING
FOR A CHANGE IN OUR DAILY WEATHER. FIRST AND FOREMOST, THERE IS
CAPE ALOFT ALLOWING FOR DAYTIME HEATING TO POP INTO THUNDERSTORMS
OVER THE INTERIOR MOUNTAINS. THE GFS IS SHOWING "MOST UNSTABLE
CAPE" VALUES IN THE 100-150J/KG RANGE OVER HUMBOLDT CO. TONIGHT
AND OVER DEL NORTE, TRINITY, AND NORTHEASTERN MENDOCINO COUNTY
TOMORROW. WETTING RAIN, LIGHTING, AND SMALL (PEA- SIZED) HAIL IS
POSSIBLE WITH THESE STORMS. THE LIFTING MECHANISM REMAINS
UNCERTAIN FOR THESE STORMS. YET, THE GFS IS SHOWING A MODERATE
AMOUNT OF VORTICITY IN THE 850MB LEVEL, WHICH COULD POSSIBLY HELP
THESE THUNDERSTORMS START THEIR LIFE.
MONDAY HAS A SLIGHTLY INCREASED CHANCE IN TRINITY COUNTY FOR THUNDER
WITH NBM PROBABILITIES 20 TO 35%, ESPECIALLY IN THE TRINITY HORN.
MID-LEVEL MOISTURE AVAILABILITY AND CONSISTENTLY WARM TEMPERATURES
CONTRIBUTE TO POTENTIAL INSTABILITY. POTENTIAL FOR GUSTY WINDS
AND DRY LIGHTNING COULD BE A FIRE WEATHER CONCERN FOR THESE AREAS.
CHANCES FOR STORMS DECREASES ON TUESDAY WITH LESS AVAILABLE MID
LEVEL MOISTURE - CONVECTIVE DEVELOPMENT LOOKS TO STAY MUCH FURTHER
EAST OF CWA IN SOUTHERN OR AND NE CA, POTENTIALLY REACHING THE
TRINITY HORN. BRIEF RIDGING ON TUE MAY BE FOLLOWED BY A DEEPER
TROUGH WED AND THU NEXT WEEK. THIS TROUGH LOOKS QUITE DRY AND MAIN
IMPACTS APPEAR TO BE A RETURN OF STRONGER GUSTY WINDS AND COOLER
TEMPERATURES.
INLAND VALLEYS WILL STRUGGLE TO BREAK 90F ON WEDNESDAY THROUGH THE
WEEK. THIS COMES A RELIEF AFTER WHAT HAS BEEN A WARM COUPLE OF WEEKS
TO START METEOROLOGICAL SUMMER. THESE COOLER TEMPERATURES WILL ALSO
BE ACCOMPANIED BY STRONGER WINDS WITH GUSTS AROUND 15-20MPH IN THE
LATER PORTION OF THE WEEK.
AVIATION...07/18Z TAFS
A SLIGHTLY DEEPER MARINE KEEP BLANKETED
THE WEST COAST THIS AFTERNOON, WITH IFR/LIFR CEILINGS BETWEEN FL003-
FL005 IMPACTING KACV AND KCEC. THE MCKINLEYVILLE AND BODEGA BAY
PROFILERS INDICATES THE MARINE LAYER IS ABOUT 2000 FEET MSL. VISIBLE
SATELLITE IMAGERY DEPICTS MULTI SIZE SCALE CYCLONIC EDDIES ALONG THE
COAST KEEPING THE SHORELINE WITH LOW CLOUDS MOVING IN AND OUT,
HELPING WITH AN IMPROVE OF VISIBILITY AT THE COASTAL TERMINALS. A
BRIEF WINDOW OF IMPROVE CONDITIONS IS POSSIBLE. OTHERWISE, EXPECT
MAINLY LIFR CONDITIONS WITH VISIBILITY IN MIST/FOG REDEVELOPING LATE
THIS AFTERNOON AND EVENING. VFR CONDITIONS IS EXPECTED TO PREVAIL AT
UKI. SURFACE WINDS WILL REMAIN GENERALLY OUT OF THE WEST AT 5-10
KT.
MARINE
GENTLE TO MODERATE NORTHERLY BREEZES ACROSS THE COASTAL
WATERS. NORTHERLY WINDS WILL CONTINUE TO SLOWLY INCREASE WITH
MODERATE TO FRESH BREEZES TONIGHT AND TUESDAY, BEFORE STRONG BREEZES
DEVELOPS SOUTH OF CAPE MENDOCINO ON WEDNESDAY. THIS WILL INCREASE
THE STEEP WIND DRIVEN WAVES, BUT GENERALLY AROUND 4 TO 5 FEET...5 TO
7 FEET IN Z470. IN ADDITION, A LONG PERIOD SOUTHWEST SWELL OF 3 FEET
AT 17 SECONDS WILL BUILD TONIGHT AND TUESDAY. THIS COULD PRESENT A
SMALL SNEAKER WAVE THREAT ON SOUTH FACING BEACHES IF IT ENDS UP
COMING IN THIS BIG. MID TO LATE WEEK, WINDS ARE EXPECTED TO STEADILY
INCREASE WITH SOME NEAR GALE TO GALE FORCE GUSTS POSSIBLE BY FRIDAY.
THERE IS A 30-50% CHANCE OF GALE FORCE GUSTS DOWNWIND PT ST GEORGE
AND CAPE MENDOCINO.
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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