367
FXUS66 KEKA 292254
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
354 PM PDT SAT MAR 29 2025
SYNOPSIS
DRY AND CALM WEATHER THROUGH THIS EVENING. STORM
WEATHER QUICKLY RETURNS LATE TONIGHT AND SUNDAY WITH STRONG GUSTY
SOUTH-SOUTHEAST WIND FOLLOWED BY PERSISTENT RAIN THROUGH THE
START OF NEXT WEEK. ISOLATED THUNDERSTORMS, SMALL HAIL AND HEAVY
DOWNPOURS POSSIBLE MONDAY THROUGH TUESDAY.
DISCUSSION
QUIET WEATHER CONDITIONS ACROSS NORTHERN CALIFORNIA
TODAY AS A SHORTWAVE RIDGE SHIFT EASTWARD ACROSS THE AREA.
AFTERNOON TEMPERATURES HAVE BEEN RUNNING 5 TO 10 DEGREES WARMER
ACROSS THE INTERIOR COMPARED WITH YESTERDAY'S READING. SURFACE
OBSERVATIONS REPORTED HIGHS GENERALLY IN THE 50'S DEGREES.
INCREASING CLOUDINESS IS EXPECTED THIS AFTERNOON AND EVENING AHEAD
OF THE NEXT STORM SYSTEM.
A SURFACE LOW WILL APPROACHES FROM THE WEST TONIGHT AND THEN DRIVE
NORTHEASTWARD NEAR THE COAST DURING THE DAY ON SUNDAY. THIS SYSTEM
WILL BRING STRONG BUT SHORT LIVED SOUTH-SOUTHEAST GUSTY WIND.
WINDS WILL INCREASE FROM SOUTH TO NORTH, WITH PEAK WIND GUSTS
FROM 35 TO 55 MPH ARE EXPECTED TO OCCUR ALONG THE COAST AND
EXPOSED RIDGES DURING THE MORNING AND AFTERNOON HOURS. THE QUICK
MOVING LOW WILL HELP WIND INCREASE QUICKLY BUT GENERALLY LIMIT THE
DURATION OF STRONG WIND TO ONLY A FEW HOURS. HAVE TO HOISTED A
WIND ADVISORY FOR THE EXPOSED RIDGES AND COASTAL HEADLAND IN DEL
NORTE AND HUMBOLDT COUNTIES.
A WARM AIR ADVECTION WILL MOVE IN FROM SOUTHWEST AND AID IN
RISING SNOW LEVELS ABOVE 6000 FEET ALONG WITH STRATIFORM
PRECIPITATION LATE TONIGHT THROUGH EARLY SUNDAY AFTERNOON,
FOLLOWED BY SHOWERS AND SLIGHT CHANCE OF ISOLATED THUNDERSTORMS.
LIGHT RAIN WILL GRADUALLY INTENSIFY AS DOWNSLOPING WIND WEAKENS.
HEAVY SNOW ACCUMULATIONS IS FORECASTED FOR ELEVATIONS ABOVE 4500
FEET. UP TO 5 INCHES OF SNOW ARE EXPECTED FOR HWY 3 IN SCOTT MT
PASS FROM EARLY MORNING THROUGH LATE AFTERNOON HOURS.
A COLD FRONT WILL PUSH ONSHORE SUNDAY EVENING WHILE THE MAIN UPPER
LEVEL TROUGH SLOWLY DIGGING SOUTHWARD ALONG THE COAST. THE
AFOREMENTIONED TROUGH WILL BRING PERIODS OF WIDESPREAD SHOWERS
ACROSS THE AREA THROUGH TUESDAY. RAIN WILL BE FOCUSED IN THE
NORTHERN HALF OF THE AREA MONDAY AND TUESDAY. OVER 48 HOURS, 2 TO
4 INCHES IS MOST LIKELY IN HUMBOLDT COUNTY, WITH UP TO 5 INCHES IN
DEL NORTE AND GENERALLY LESS THAN 1.5 INCHES FURTHER SOUTH. A
COLDER DEEP-LAYER AIRMASS WILL SUBSEQUENTLY SPREAD SOUTH ACROSS
THE WEST COAST SUNDAY NIGHT AND PERSISTING THROUGH TUESDAY, WITH
850 MB TEMPERATURES AROUND -3C, 700 MB TEMPERATURE FROM -10C TO
-12C, AND 500 MB BELOW -30C. THE COLD AIRMASS WILL AID IN STEEP
LAPSE RATES AND INCREASING INSTABILITY ENVIRONMENT. ISOLATED
THUNDERSTORMS, SMALL HAIL AND BRIEF HEAVY DOWNPOURS WILL BE
POSSIBLE WITH THE STRONGEST SHOWERS.
SNOW LEVELS WILL LIKELY DROP THROUGH THE EVENT AS THE TROUGH
SLOWLY LUMBERS ON LAND, PARTICULARLY IN TRINITY COUNTY. THE
GREATEST POTENTIAL FOR LOWER ELEVATION SNOW WILL BE IN THE MORNING
EARLY HOURS TUESDAY AND AGAIN WEDNESDAY. VARYING WITH THE TIME OF
DAY, THE GFS SHOWS SNOW LEVELS AS SLOW AS 1500 FEET. THAT SAID,
IMPACTS WILL MOSTLY BE RESTRICTED TO TRINITY COUNTY (MOSTLY ALONG
HIGHWAYS 3 AND 36) WITH LITTLE CHANCE (LESS THAN 20%) OF EVEN 3
INCHES OF SNOW ON ANY HIGHWAY PASS IN OTHER COUNTIES. IN TRINITY,
4 TO 12 INCHES IS MOST LIKELY BY MIDWEEK ALONG HIGHWAYS 3 AND 36
WITH LESSER TRACE AMOUNTS ON HIGHWAY 299. THE EXTENDED FORECAST
SHOW CONDITIONS FILIALLY DRYING OUT BY LATE IN THE WEEK. /ZVS
AVIATION
FLIGHT CATEGORIES ARE VFR WITH LIGHT WINDS THIS AFTERNOON
THROUGH THE FORECAST AREA. A COMPACT AREA OF LOW PRESSURE WILL PASS
BY OFF THE COAST TONIGHT THROUGH SUNDAY. THIS WILL BRING LIGHT
RAINFALL AND STRENGTHENING SOUTHERLY WINDS AT THE SURFACE AND ALOFT.
AREAS OF LOW LEVEL WIND SHEAR WILL BE LIKELY AS WINDS ALOFT QUICKLY
INCREASE FROM THE SOUTHEAST EARLY SUNDAY MORNING. CEILINGS WILL
LOWER AFTER 10Z SUNDAY AS THE RAINFALL BEGINS TO ARRIVE.
PROBABILITIES ARE MODERATE TO HIGH FOR MVFR CEILINGS (50-70) AS THE
FRONT SWEEPS THROUGH. PROBABILITIES FOR IFR ARE LOW, AROUND 20% FOR
THE TAF SITES. /JJW
MARINE
THE DOMINANT WESTERLY SWELL HAS CONTINUED TO DROP TODAY
ALLOWING THE SMALL CRAFT ADVISORIES TO EXPIRE WITH SEAS NOW BELOW 10
FT. THIS BRIEF LULL IN SEAS AND WINDS WILL BE SHARPLY INTERRUPTED LATE
TONIGHT WHEN A PASSING COMPACT AREA OF LOW PRESSURE BEGINS MOVING
PAST THE WATERS. WINDS WILL SNAP SOUTHERLY AFTER 11 PM TONIGHT, AND
WILL QUICKLY ADVANCE TO GALE STRENGTH BY 2 AM IN THE OUTERS, WITH
FURTHER EXPANSION AND STRENGTHENING IN ALL ZONES AND GUSTS UP TO 45
KTS AS THE MORNING PROGRESSES. THESE WINDS WILL GENERATE STEEP SEAS
OF 10 TO 13 FT. WINDS AND SEAS WILL EASE SOME SUNDAY EVENING, BUT A
SECONDARY APPROACHING TROUGH WILL CARRY PERIODS OF NEAR GALE TO GALE
CONDITIONS IN THE WATERS INTO TUESDAY. AS THE BROAD PACIFIC
NORTHWEST TROUGH BEGINS A SLOW ADVANCEMENT TOWARD THE COAST, A SOLID
FETCH OF STRONG WESTERLY WINDS WILL DRIVE IN VERY STEEP, LARGE AND
POTENTIALLY HAZARDOUS WESTERLY SEAS MONDAY EVENING THROUGH TUESDAY.
SEAS UP TO 19 FT ARE CURRENTLY FORECAST, BUT SIMILAR SETUPS HAVE
GENERATED LARGER SEAS THAN FORECAST. /JJW
EKA WATCHES/WARNINGS/ADVISORIES
CA...
WIND ADVISORY FROM 10 AM TO 4 PM PDT SUNDAY FOR CAZ101-102.
WIND ADVISORY FROM 8 AM TO 2 PM PDT SUNDAY FOR CAZ104>106.
WINTER WEATHER ADVISORY FROM 5 AM TO 6 PM PDT SUNDAY FOR
CAZ107.
NORTHWEST CALIFORNIA COASTAL WATERS...
GALE WARNING FROM 9 AM TO 7 PM PDT SUNDAY FOR PZZ450.
GALE WARNING FROM 5 AM TO 1 PM PDT SUNDAY FOR PZZ455.
GALE WARNING FROM 5 AM TO 7 PM PDT SUNDAY FOR PZZ470.
GALE WARNING FROM 2 AM TO 1 PM PDT SUNDAY FOR PZZ475.
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