822
FXUS66 KEKA 201304
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
504 AM PST THU FEB 20 2025
SYNOPSIS
DRY AND WARMER WEATHER IS EXPECTED TODAY AND FRIDAY.
A SERIES OF WARM FRONTAL SYSTEMS WILL BRING A CHANCE FOR RAIN
THIS WEEKEND INTO EARLY NEXT WEEK.
DISCUSSION
SATELLITE IMAGERY SHOWED LOW CLOUDS AND PATCHES OF FOG
MOSTLY IN THE INTERIOR AND COASTAL RIVER VALLEYS THIS MORNING. FOG
AND LOW CLOUDS SHOULD CLEAR OUT BY LATE MORNING IN MOST AREAS, BUT
WILL PROBABLY PERSIST INTO THE EARLY AFTERNOON HOURS IN TRINITY
AND NE HUMBOLDT. TODAY WILL BE A GOOD DAY TO TAKE CARE OF ANY
OUTDOOR PROJECTS WITH GREATER POTENTIAL FOR SUNSHINE AFTER THE
FOG AND LOW CLOUDS BURN OFF. FRIDAY SHOULD ALSO BE A DRY DAY AS
HIGH PRESSURE HOLDS OVER THE AREAS, BUT ONCE AGAIN SUSPECT THERE
WILL BE FAIR AMOUNT OF FOG AND LOW CLOUDS IN THE VALLEYS. ALSO,
SIMULATED REFLECTIVITIES FROM A FEW OF THE HIGH RESOLUTION CAMS
INDICATE WEAK RETURNS SPILLING OVER THE RIDGE AND A FEW LIGHT
SHOWERS OR SPRINKLES ARE NOT COMPLETELY IMPOSSIBLE IN THE LATE
AFTERNOON AND EVENING HOURS ON FRIDAY.
A LONG FETCH OF MOISTURE EMANATING FROM THE SUBTROPICS (PWATS OVER
250% OF NORMAL) WILL GET INGESTED INTO A FRONTAL SYSTEM THAT WILL
APPROACH THE WEST COAST ON SATURDAY. THE FRONT WILL MOST LIKELY
STALL OFFSHORE OR JUST TO THE NORTH OF THE ORCA BORDER WITH
EPISODIC WARM FRONTS PRODUCING BOUTS OF MODERATE TO LOCALLY HEAVY
RAIN ACROSS DEL NORTE COUNTY. BRUNT OF THIS ATMOSPHERIC RIVER
WILL BE AIMED NORTH OF THE AREA WITH DEL NORTE ON THE SOUTHERN
EDGE OF THE IVT PLUME MAX (AR1/AR2 CONDITIONS WITH LOWER
PROBABILITIES FOR AR3). THUS EXPECT MOSTLY BENEFICIAL RAINFALL.
MINOR NUISANCE FLOODING WILL BE POSSIBLE AND AS WE HAVE SEEN WITH
MULTIPLE RAINSTORMS, POSSIBLE LANDSLIDES IN STEEP TERRAIN ON 199.
HEAVIEST RAIN APPEARS TO ARRIVE SATURDAY NIGHT (4PM-4AM). OTHERWISE,
EXPECT MILD TEMPERATURES WITH A CHANCE FOR LIGHT RAIN FOR THE
REMAINDER OF THE AREA DURING THE WEEKEND. GUSTY WINDS WILL ALSO
OCCUR WITH THIS STATIONARY BOUNDARY AND MINOR IMPACTS ARE
POSSIBLE ESPECIALLY OVER THE COASTAL HEADLANDS. A FRONTAL WAVE IS
FORECAST TO DEVELOP EARLY NEXT WEEK (MONDAY) AND STRONGER WIND
GUSTS TO 40 MPH OR MORE ARE MORE PROBABLE AS A COLD FRONTAL
BOUNDARY PUSHES ACROSS THE AREA. THE TIMING REMAINS UNCERTAIN,
THOUGH THE ECMWF ENSEMBLE INDICATES HIGHEST PROBABILITIES MONDAY
AFTERNOON/EVENING AND NBM 90TH PERCENTILE MAX GUSTS ARE ON THE
ORDER OF 50 TO 60MPH IN THE DEL NORTE COUNTY MOUNTAINS. AT THIS
POINT IT LOOKS BORDERLINE FOR EVEN A WIND ADVISORY FOR THE LOWER
ELEVATIONS. THERE COULD BE GREATER WIND IMPACTS ON MONDAY AND THIS
WILL NEED TO BE WATCHED.
EXTENDED GUIDANCE INDICATES BROAD UPPER RIDGING BUILDING BY MID
WEEK (WED) AFTER SHORTWAVE TROUGH PASSAGE. UPSTREAM WESTERLY FLOW
IS FORECAST TO UNDERCUT THE RIDGE, INCREASING THE POTENTIAL FOR A
CUT-OFF LOW TO DEVELOP EITHER OFFSHORE SW OF PT ARENA OR RIGHT
OVER THE FORECAST AREA BY LATE NEXT WEEK. THIS SORT OF FLOW PATTERN
RESEMBLES IS FAVORABLE FOR INTERIOR CONVECTION AND TSTMS. DB
AVIATION
SATELLITE EARLY THIS MORNING IS SHOWING LOW CLOUDS ACROSS
MUCH OF THE INTERIOR RIVER VALLEYS AND AROUND HUMBOLDT BAY. HOWEVER,
THE TERMINALS HAVE BEEN LARGELY UNAFFECTED SO FAR. THE TERMINALS ARE
LIKELY TO REMAIN VFR FOR MUCH OF THE DAY, OUTSIDE SOME OCCASIONAL
INTERRUPTIONS OF SHALLOW CLOUDS AND/OR FOG THIS MORNING. LOW CLOUDS
ARE LIKELY TO LIFT AND SCATTER OUT SHORTLY AFTER SUNRISE. OFFSHORE
FLOW ALOFT WEAKENS THIS EVENING AND OVERNIGHT, WHICH COULD BRING
STRATUS BACK TO THE COAST. JB
MARINE
NORTHERLY WINDS ARE FORECAST TO RAMP UP TODAY, BRINGING
MODERATE TO FRESH BREEZES THIS AFTERNOON. STRONGER WINDS ARE LIKELY
IN THE LEE OF CAPE MENDOCINO. ALONG WITH SHORT PERIOD WIND WAVES,
SEAS WILL BE CHARACTERIZED BY A DECAYING MID-PERIOD WESTERLY SWELL.
WINDS EASE AND TURN WESTERLY TONIGHT INTO FRIDAY, BUT SEAS WILL
REMAIN ELEVATED AS ANOTHER LONG PERIOD WESTERLY SWELL OF 10-12 FT
FILLS IN. WINDS INCREASE AGAIN AND TURN SOUTHERLY FRIDAY NIGHT AS
ANOTHER SYSTEM APPROACHES THE AREA. SOUTHERLY WINDS REMAIN
ELEVATED, ESPECIALLY IN THE NORTHERN WATERS, THROUGH THE WEEKEND
INTO EARLY NEXT WEEK AS TROUGHING CONTINUES. SEAS WILL BE
CHARACTERIZED BY STEEP SOUTHERLY WIND WAVES AND ADDITIONAL
WESTERLY LONG-PERIOD SWELLS. JB
BEACH HAZARDS
A WESTERLY SWELL OF AROUND 10-12 FT AT 16 SECONDS
IS FORECAST TO BUILD INTO THE WATERS FRIDAY. WITH LIGHT WINDS AND
MILD WEATHER EXPECTED FRIDAY, BEACHGOERS SHOULD BE CAUTIOUS AS THIS
SWELL PRESENTS A MODERATE SNEAKER WAVE THREAT. BE CAUTIOUS VISITING
STEEP BEACHES AND JETTIES AND REMEMBER TO NEVER TURN YOUR BACK ON
THE OCEAN. JB
EKA WATCHES/WARNINGS/ADVISORIES
CA...
BEACH HAZARDS STATEMENT FROM LATE TONIGHT THROUGH LATE
FRIDAY NIGHT FOR CAZ101-103-104-109.
NORTHWEST CALIFORNIA COASTAL WATERS...
SMALL CRAFT ADVISORY FROM 3 PM FRIDAY TO 9 PM PST SATURDAY
FOR PZZ450-470.
SMALL CRAFT ADVISORY UNTIL 3 AM PST FRIDAY FOR PZZ455-475.
VISIT US AT HTTPS://WWW.WEATHER.GOV/EUREKA
FOLLOW US ON FACEBOOK AND TWITTER AT:
HTTPS://WWW.FACEBOOK.COM/NWSEUREKA
HTTPS://WWW.TWITTER.COM/NWSEUREKA
FOR FORECAST ZONE INFORMATION
SEE THE FORECAST ZONE MAP ONLINE:
HTTPS://WWW.WEATHER.GOV/IMAGES/EKA/ZONEMAP.PNG
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page