598
FXUS66 KEKA 200555
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
1055 PM PDT MON MAY 19 2025
SYNOPSIS
WARM AND DRY CONDITIONS EXPECTED THROUGH WEDNESDAY AS HIGH
PRESSURE BUILDS INTO THE EASTERN PACIFIC. UPPER LEVEL DISTURBANCES
POSSIBLE LATE THIS WEEK AND WEEKEND WITH COOLING AND POTENTIAL FOR
LIGHT RAIN.
DISCUSSION
A WEAK FRONTAL BOUNDARY MOVED ACROSS THE REGION THIS
AFTERNOON/EVENING, PROVIDING A LIFTING MECHANISM FOR DRIZZLE TO
DEVELOP ALONG THE COAST WITHIN AN ALREADY WIDESPREAD MARINE CLOUD
LAYER. VERY LITTLE ACCUMULATIONS WERE RECORDED - CHANCES WILL
CONTINUE TO DETERIORATE OVERNIGHT. AS MENTIONED IN THE PREVIOUS
DICUSSION, COOLER TEMPERATURES COULD PRODUCE SOME PATCHY FROST IN
INTERIOR VALLEYS OF TRINITY COUNTY, BUT CLOUD COVER COULD BE A
HINDRANCE.
STRATUS WILL BECOME DISORGANIZED AND SCATTER OVERNIGHT INTO TUESDAY
AS A RIDGE BUILDS INTO THE PNW. BREEZY NNW WINDS EXPECTED,
ESPECIALLY ALONG THE COAST. HI-RES MODELS INDICATE HIGH TEMPERATURES
IN THE 70'S AND LOW 80'S BENEATH MOSTLY CLEAR SKIES. MINOR HEAT RISK
WILL BEGIN TO CREEP INTO THE EASTERN PORTIONS OF LAKE AND MENDOCINO
COUNTY THROUGH WEDNESDAY, BUT NO MAJORLY CONCERNING.
WEDNESDAY STILL APPEARS TO BE WARMEST DAY OF THE WEAK AS HIGH
PRESSURE CONTINUES TO BUILD. WARM AND DRY CONDITIONS WITH HIGHS IN
THE MID TO UPPER 80'S ARE EXPECTED ACROSS THE INTERIOR; COAST WILL
BE DAMPENED BY RETURNING MARINE STRATUS. NBM PROBABILITIES DROP OFF
SIGNIFICANTLY BETWEEN 85 AND 90 DEGREES - THIS MAY BE THE CAP FOR
LAKE AND MENDOCINO COUNTIES, WITH POTENTIAL FOR THE HOTTEST TEMPS
IN UKI AND COVELO. RH VALUES WILL DIP INTO THE 20-30% RANGE EAST
OF THE COAST RANGES. BREEZY CONDITIONS WITH 10 TO 20 MPH GUSTS
POSSIBLE IN LAKE COUNTY WEDNESDAY AFTERNOON WILL ENHANCE FIRE
WEATHER CONDITIONS, BUT DOES NOT QUITE MEET RED FLAG CRITERIA,
ESPECIALLY WITH CURRENT STATUS OF FUELS.
THURSDAY AND FRIDAY BROAD/WEAK TROUGHING WILL DRIFT BY TO OUR
NORTH, BUT WILL NOT HAVE MUCH MORE EFFECT THAN MID LEVEL CLOUD
COVER. A SHORTWAVE DIPPING INTO NORCAL FRIDAY INTO SATURDAY COULD
BRING SOME LIGHT SHOWERS TO NORTHERN COUNTIES. A MORE SIGNIFICANT
PATTERN CHANGE IS POSSIBLE SUNDAY THROUGH EARLY NEXT WEEK. MODEL
CLUSTERS ARE NOT YET ALIGNED BUT VERY LOW POTENTIAL FOR RAINFALL IS
STILL POSSIBLE.
AVIATION
NORTHERLIES INCREASE LATER TONIGHT INTO TUESDAY MORNING
AND SHOULD SCOUR OUT THE LOW LEVEL MOISTURE OVER COASTAL AERODROMES.
LINGERING MVFR CEILINGS ARE STILL LIKELY (60% CHANCE) TUE AM,
HOWEVER. OTHERWISE, VFR CONDITIONS WITH GUSTY NORTH TO NORTHWESTERLY
WINDS ARE FORECAST FOR KUKI. THERE IS A 50% CHANCE FOR LOW LEVEL
TURBULENCE AND/OR LOW LEVEL SPEED SHEAR UKI AND VICINITY OVERNIGHT
AS SURFACE GUSTINESS DECOUPLES. GUSTY NORTHERLY AND NORTHWESTERLY
WINDS AND SHALLOW LOW LEVEL TURBULENCE AND/OR LOW LEVEL SPEED SHEAR
INCREASES THROUGHOUT DURING THE DAY ON TUESDAY. DB/MH
MARINE
MARINE CONDITIONS ARE FORECAST TO DETERIORATE ON TUESDAY
AS NORTHERLY WINDS AND STEEP WAVES INCREASE THROUGH THE DAY. HREF
PROBABILISTIC GUIDANCE CONTINUES TO SUPPORT PEAK GUSTS TO 35-40KT IN
THE LEE OF CAPE MENDOCINO AS AN EXPANSION FAN GROWS THROUGH THE DAY
ON TUESDAY AND REACHES MAXIMUM COVERAGE BY LATE AFTERNOON INTO THE
EVENING HOURS. A SMALLER AND SHORTER DURATION EXPANSION FAN REGION
ALSO DEVELOPS IN THE LATE AFTERNOON ACROSS THE NORTHERN WATERS,
AROUND AND JUST DOWNWIND OF PT ST GEORGE. COVERAGE APPEARS MINIMAL
FOR A GALE WARNING FOR THE NORTHERN WATERS. FOR NOW WILL HOIST
ADVISORIES FOR SMALL CRAFT GIVEN THE RAMP UP OF STEEP NORTHERLY
WAVES OF 6-8 FT ON TOP OF AN INCOMING NW SWELL OF 8-10 FT. COMBINED
SEAS (SIGNIFICANT WAVE HEIGHTS) ARE FORECAST TO REACH 10-13 FEET,
HIGHEST SOUTH OF CAPE MENDO, BY TUE AFTERNOON AND EVENING. MARINE
CONDITIONS ARE FORECAST TO EASE UP TOWARD THE END OF THE WEEK,
EXCEPT SOUTH OF CAPE MENDOCINO WHERE WIND AND SEAS WILL LIKELY
REMAIN HAZARDOUS FOR SMALL CRAFT AND INEXPERIENCED MARINERS. DB/MH
EKA WATCHES/WARNINGS/ADVISORIES
CA...
NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...
SMALL CRAFT ADVISORY FROM 3 PM TUESDAY TO 3 AM PDT
WEDNESDAY FOR PZZ450.
SMALL CRAFT ADVISORY UNTIL 9 PM PDT WEDNESDAY FOR PZZ455.
SMALL CRAFT ADVISORY FROM NOON TUESDAY TO 9 PM PDT
WEDNESDAY FOR PZZ470.
SMALL CRAFT ADVISORY UNTIL NOON PDT TUESDAY FOR PZZ475.
GALE WARNING FROM NOON TUESDAY TO 3 AM PDT WEDNESDAY FOR
PZZ475.
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