976
FXUS66 KEKA 181242
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
542 AM PDT SUN MAY 18 2025
SYNOPSIS
NORTHERLY WINDS CONTINUE TO GUSTS UP THIS MORNING,
ALTHOUGH AT A REDUCED AND INTERMITTENT PATTERN. MONDAY THE WARMUP
STARTS, BUT THERE MAY BE SOME CLOUDS IN THE AFTERNOON. TUESDAY AND
WEDNESDAY ADDITIONAL WARMING IS EXPECTED WITH HIGHS AROUND 90
INLAND. COOLER TEMPERATURES ARE EXPECTED LATE IN THE WEEK.
DISCUSSION
NORTHERLY WINDS REMAIN GUSTY TODAY WITH A BIT LESS
ZEAL THAN SATURDAY'S KITE WORTHY BREEZES. AFTER THE PASSAGE OF AN
UPPER LEVEL TROUGH AND ITS ASSOCIATED GUSTY NORTHWEST WINDS, A
RIDGING PATTERN UPSTREAM BEGINS TO BUILD IN. THE EFFECTS OF THE HIGH
PRESSURE OFFSHORE IN THE EASTERN PACIFIC WILL BE MUTED BY A SMALLER
AMPLITUDE TROUGH THAT IS TRACING THE LOW PRESSURE IN THE UPPER AIR
PATTERN, ALBEIT FURTHER NORTH AND TRAILING. COLD AIR ADVECTION WILL
SLIGHTLY BREECH NORTHERN CALIFORNIA THIS MORNING AND RETREAT BEFORE
THE NEXT WARM SECTOR ARRIVES MONDAY MORNING. ANOTHER UPPER LEVEL LOW
APPROACHES MONDAY AFTERNOON BUT WILL BE BLOCKED/MORPHED BY THE
OFFSHORE HIGH PRESSURE WHICH WILL FLATTEN OUT THE SHORTWAVE TROUGH A
BIT, LEADING TO GEOSTROPHIC FLOW ALOFT. THIS WILL INCREASE WINDS
NEAR THE SURFACE AS THE GRADIENT GETS STEEPER NEAR THE COASTLINE.
STRONG NORTHERLY WINDS ARE EXPECTED TUESDAY EVENING ONCE AGAIN.
THE HIGHER ELEVATION VALLEYS OF TRINITY COUNTY MAY SEE SOME
TEMPERATURES 36 OR BELOW THIS MORNING, SO A FROST ADVISORY HAS
BEEN ISSUED FOR HAYFORK, WEAVERVILLE, DOUGLAS CITY, AND AREAS
CLOSE BY. THIS AFTERNOON GUSTY WINDS ARE EXPECTED ONCE AGAIN WITH
GUSTS TO 30 MPH IN MANY OF THE MORE WIND PRONE AREAS. HIGH
TEMPERATURES IN THE INLAND AREAS WILL BE IN THE 60S TO LOW 70S
WHILE THE COAST IS EXPECTED TO REMAIN NEAR 60.
WEDNESDAY IS EXPECTED TO BE THE HOTTEST DAY OF THE WEEK IN THE
INLAND AREAS WITH HIGHS IN THE UPPER 80S TO NEAR 90 IN THE WARMER
VALLEYS. HEAT RISK INCREASES SLIGHTLY, BUT REMAINS MAINLY IN THE
MINOR CATEGORY.
THURSDAY THROUGH SATURDAY THE FLOW ALOFT IS EXPECTED TO BECOME MORE
ZONAL. THIS WILL ALLOW TEMPERATURES INLAND TO COOL AND THE MARINE
LAYER TO BECOME MORE ROBUST. THERE WILL BE SOME INDIVIDUAL
SHORTWAVES MOVING THROUGH THAT COULD BRING SOME LIGHT RAIN, BUT
OVERALL IT LOOKS FAIRLY DRY. MKK /EYS
AVIATION
MARINE INFLUENCE HAS REMAINED LIFTED AND RAGGED IN THE
WAKE OF A PASSING SHORTWAVE AND PERSISTENT NORTH WINDS OVERNIGHT.
THAT SAID, STRATUS HAS GENERATED AT LEAST LOCALLY MVFR CONDITIONS
AROUND HUMBOLDT BAY. MODELS SUGGEST THE BAY WILL BE SLOW TO CLEAR
THIS MORNING (TAKING UNTIL AROUND NOON) BUT OTHERWISE VFR CONDITIONS
WILL DOMINATE ALL ACROSS THE AREA. WEAKER WINDS AND MORE STABLE AIR
WILL LIKELY ENABLE A LOWER AND MORE WIDESPREAD MARINE LAYER TONIGHT,
THOUGH ANY IFR CONDITIONS WILL MOST LIKELY REMAIN SPORADIC AT BEST.
/JHW
MARINE
MODERATE TO STRONG NORTH WINDS WILL CONTINUE TO DECREASE
THROUGH THE DAY TODAY, ESPECIALLY IN THE NORTHERN WATERS WHERE GUSTS
WILL DROP BELOW 20 KTS BY EARLY THIS AFTERNOON. GUSTS WILL REMAIN
MODERATE IN THE SOUTHERN WATERS WITH FEW GUSTS OVER 30 KTS. STRONGER
NORTH WINDS WILL RETURN AND SPREAD NORTH ONCE AGAIN AROUND TUESDAY
BEFORE WEAKENING AGAIN LATER IN THE WEEK. THE SEA STATE WILL
CONTINUE TO BE MOSTLY CONTROLLED BY SHORT PERIOD WIND WAVES THROUGH
EARLY NEXT WEEK. SHORT PERIOD SEAS WILL BE AUGMENTED BY MODEST MID
PERIOD NORTHWEST SWELLS UP TO AROUND 4 FEET. A STEEPER NORTHWEST
SWELL WILL BUILD ALONGSIDE NORTH WIND TUESDAY REACHING UP TO 8 FEET
AT 12 SECONDS. /JHW
EKA WATCHES/WARNINGS/ADVISORIES
CA...
FROST ADVISORY UNTIL 10 AM PDT THIS MORNING FOR CAZ107-108.
NORTHWEST CALIFORNIA COASTAL WATERS...
SMALL CRAFT ADVISORY UNTIL 9 AM PDT THIS MORNING FOR PZZ450-
470.
SMALL CRAFT ADVISORY UNTIL 3 AM PDT MONDAY FOR PZZ455-475.
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