257
FXUS66 KEKA 100748
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
1248 AM PDT FRI JUL 10 2026
KEY MESSAGES
* COASTAL STRATUS AND FOG: MARINE LOW CLOUDS AND AREAS OF FOG
WILL AFFECT THE IMMEDIATE COAST, BRINGING COOL DAYTIME
TEMPERATURES AND OVERNIGHT DAMPNESS.
* INTERIOR HEAT: AN UPPER-LEVEL RIDGE WILL EXPAND WESTWARD,
CAUSING TEMPERATURES TO RISE ABOVE NORMAL ACROSS INLAND VALLEYS
INCLUDING LAKE, TRINITY, AND INTERIOR MENDOCINO COUNTIES
THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK.
SYNOPSIS
SHALLOW COASTAL STRATUS AND FOG WILL PERSIST ALONG THE
IMMEDIATE COAST WITH LIMITED AFTERNOON CLEARING THROUGH FRIDAY,
WITH AREAS ONLY SLIGHTLY FURTHER INLAND THAN THE BEACHES
EXPERIENCING PERIODIC AFTERNOON CLEARING. INLAND AREAS WILL
REMAIN DRY AND HOT UNDER A BUILDING UPPER LEVEL RIDGE.
DISCUSSION
AN UPPER-LEVEL RIDGE OVER THE SOUTHWEST US IS
EXPANDING WESTWARD OVER NORTHWEST CALIFORNIA. SUBSIDENCE ALOFT IS
COMPRESSING THE MARINE LAYER, KEEPING IT SHALLOW AND CONFINED TO
THE COAST AND ADJACENT LOWER VALLEYS OVERNIGHT TO EARLY/MID
MORNING. INLAND AREAS WILL EXPERIENCE WARMING, WITH AFTERNOON
HIGH TEMPERATURES IN THE MID TO UPPER 90S BECOMING WIDESPREAD
ACROSS THE INTERIOR VALLEYS OF TRINITY, MENDOCINO, AND LAKE
COUNTIES THIS AFTERNOON.
EARLY NEXT WEEK, THE PLACEMENT OF THE UPPER RIDGE WILL DETERMINE
THE TRACK OF POTENTIAL MONSOONAL MOISTURE. CURRENT GUIDANCE
INDICATES A CONTINUING WARMING TREND FOR THE INTERIOR, WITH A LOW
PROBABILITY OF THUNDERSTORM DEVELOPMENT OVER NORTHEASTERN TRINITY
COUNTY.
AVIATION
FLIGHT CATEGORIES OVERNIGHT INTO FRIDAY MORNING AT
THE COASTAL TERMINALS WILL BE INFLUENCED BY SUBSIDENCE AND LIGHT
SOUTHERLY WINDS, LIKELY TO REDUCE FLIGHT CATEGORIES TO LIFR. KCEC
HAS A HIGH PROBABILITY OF CEILINGS LESS THAN 1000 FEET DURING THE
PRE DAWN HOURS AND WITHIN THAT TIMEFRAME IT LOOKS AS THOUGH GFS
GUIDANCE IS SUGGESTING SEVERAL HOURS OF SUB 500FT CEILINGS, OF
WHICH THERE IS ABOUT A 30% CHANCE OF OCCURRENCE AROUND 12Z-16Z.
KACV WILL HAVE SIMILAR CONDITIONS WITH LIGHT SOUTHERLY WINDS
TURNING WESTERLY BY DAWN. BOTH TERMINALS IMPROVING TO MVFR BY
FRIDAY AFTERNOON. KUKI MAY HAVE A FEW INTERMITTENT GUSTS, SIMILAR
TO THURSDAY'S LATE AFTERNOON PUSH THAT ONLY LASTED A FEW HOURS BUT
VFR MOSTLY EXPECTED THROUGH FRIDAY. /EYS
MARINE
THE SURFACE PRESSURE GRADIENT BETWEEN AN OFFSHORE
SURFACE HIGH PRESSURE SYSTEM AND AN INLAND SURFACE THERMAL LOW IS
STARTING TO WEAKEN. SOUTH OF CAPE MENDOCINO, SUSTAINED NORTHWEST
WINDS OF 20 TO 25 KNOTS ARE GENERATING STEEP, WIND-DRIVEN SEAS. A
GALE WARNING FOR THE SOUTHERN OUTER WATERS IS OUT BUT SHOULD
EXPIRE BY FRIDAY MORNING DUE TO DIMINISHING POTENTIAL GUSTS UP TO
40 KNOTS. FOR THE NORTHERN OUTER WATERS, WINDS OF 20 TO 25 KNOTS
COMBINED WITH STEEP 9-FOOT WAVES AT SHORT 8-SECOND PERIODS SATISFY
ADVISORY CRITERIA.
EKA WATCHES/WARNINGS/ADVISORIES
CA...
NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...
SMALL CRAFT ADVISORY UNTIL 11 AM PDT FRIDAY FOR PZZ415-450.
SMALL CRAFT ADVISORY UNTIL 10 PM PDT FRIDAY FOR PZZ455-470.
GALE WARNING UNTIL 8 AM PDT FRIDAY FOR PZZ475.
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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