911
FXUS66 KEKA 272225
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
325 PM PDT THU MAR 27 2025
SYNOPSIS
STRONG WINDS AND WAVES OF RAIN WILL CONTINUE TO IMPACT
THE ARE THROUGH THE DAY WITH CALMER WINDS BUT MORE CONSISTENT RAIN
TONIGHT. CONDITIONS WILL BRIEFLY CLEAR AND CLAM SATURDAY BUT STORMY
CONDITIONS RETURN SUNDAY AND PERSIST THROUGH MOST OF THE FIRST WEEK
OF APRIL.
DISCUSSION
A 985 MB PACIFIC CYCLONE CENTERED OFFSHORE WA/OR
COAST CONTINUE IMPACTING THE PACIFIC NORTHWEST AND NORTHERN
CALIFORNIA THIS AFTERNOON. DOPPLER RADAR DEPICT SCATTERED TO
NUMEROUS SHOWERS MOVING NORTHEAST ACROSS THE FORECAST AREA, WITH
THE BULK OF THE RAIN IN DEL NORTE AND NORTHERN HUMBOLDT. VERY
WINDY TO STRONG SOUTHERLY WINDS CONTINUE IMPACTING THE COASTAL
HEADLANDS AND EXPOSED RIDGES. ALTHOUGH, THIS WINDS HAS PEAKED UP
THIS AFTERNOON AS A LOW LEVEL JET (925-850 MB) UP TO AROUND 65 KTS
MOVES ALONG THE NORTH COAST. SURFACE OBSERVATIONS HAVE REPORTED
GUSTS FROM 40 TO 55 MPH ALONG THE COASTAL HEADLANDS AND EXPOSED
RIDGES, LOCALLY STRONGER OVER THE MORE PROMINENT HIGHER TERRAIN.
DOWNSLOPING WINDS HAVE BEEN KEEPING THE PRECIPITATION GENERALLY
LIGHT FOR THE LOWER ELEVATIONS, WITH 0.15 TO 0.30 AROUND THE
HUMBOLDT BAY AS OF 2PM LOCAL TIME. WITH WINDS GRADUALLY WEAKEN
THIS EVENING AND TONIGHT, PERIODS OF MODERATE TO LOCALLY HEAVY
RAINFALL ARE EXPECTED.
FOR THE INTERIOR, THE TROUGH IS ASSOCIATED WITH ONLY VERY MARGINAL
COLD AIR, KEEPING SNOW LEVELS ABOVE 4000 FEET. WHILE 6 TO 12
INCHES IS LIKELY AROUND SCOTT MOUNTAIN ON HIGHWAY 3, NOT OTHER
TRAVEL CORRIDOR IMPACTS ARE EXPECTED INTO FRIDAY.
A SERIES OF SHORTWAVES TROUGH EMBEDDED WITHIN THE UPPER-LEVEL
TROUGH WILL MOVES ACROSS THE AREA TONIGHT THROUGH FRIDAY NIGHT.
COLD AIR ALOFT WILL PROMOTE ENOUGH INSTABILITY FOR ISOLATED LOW-
TOPPED THUNDERSTORMS DEVELOPMENT ALONG THE COAST THIS EVENING
THROUGH FRIDAY. THE GREATEST RISK FROM THUNDERSTORMS WILL BE
LIGHTNING STRIKES AND PERHAPS BRIEF HEAVY RAIN. PROGRESSIVE STORM
MOTIONS WILL ALSO PRECLUDE ANY MAJOR CONCERNS FOR FLASH FLOODING
OR DEBRIS FLOW. IN ADDITION, BRIEF HEAVY DOWNPOURS ARE EXPECTED
WITH THE STRONGER SHOWERS.
LINGERING SHOWERS WILL GRADUALLY TO TAPER OFF FRIDAY NIGHT INTO
SATURDAY MORNING, WITH A BRIEF SHORTWAVE RIDGE BUILDING IN THE
WAKE OF THE UPPER-LEVEL SHORTWAVE TROUGH. COLD OVERNIGHT
TEMPERATURES ARE EXPECTED FOR FRIDAY NIGHT INTO SATURDAY, WITH
LOW TEMPERATURES IN THE MID 30'S TO LOW 40'S..WHILE UPPER 20'S TO
LOW 30'S FOR TRINITY COUNTY. FOR AREAS WHERE SKIES CLEAR OUT
QUICKLY, AREAS OF VALLEY FOG ARE EXPECTED TO DEVELOP FRIDAY NIGHT
INTO SATURDAY.
STORMY WEATHER WILL MOST LIKELY RETURN AROUND SUNDAY. THE SYSTEM
SUNDAY WILL BE DRIVEN BY A COMPACT SURFACE LOW THAT HAS SHOW
SIGNIFICANT VARIABILITY IN MODELS, THOUGH IT IS VERY UNLIKELY TO
BE AS WINDY AS THE CURRENT SYSTEMS. RAINY WEATHER WILL CONTINUE
THROUGH MOST OF THE FIRST WEEK OF APRIL. BY EARLY NEXT WEEK, THE
MAIN IMPACT CONCERNS WILL SHIFT FROM WIND TO RAIN. SATURATED SOILS
AND WEAKER DOWNSLOPING EFFECTS WILL BOTH ENHANCE PRECIPITATION
POTENTIAL. 3 TO 5 INCHES OF STEADY RAINFALL IS MOST LIKELY FOR
POPULATED AREAS THROUGH NEXT WEEK. LONG RANGE CNRFC GUIDANCE
CURRENTLY SHOWS A ROUGHLY 20% CHANCE OF MAIN RIVERS REACHING FLOOD
STAGE BY THE END OF NEXT WEEK. ADDITIONALLY, SNOW LEVELS WILL
LIKELY DROP THROUGH THE EVENT, PARTICULARLY IN TRINITY COUNTY. THE
POSSIBILITY OF IMPACTFUL SNOW WILL HAVE TO BE WATCHED CLOSELY BY
MID NEXT WEEK.
AVIATION
AVIATION CONCERNS/FLIGHT HAZARDS ACROSS THE REGION
TODAY ARE BEING SIGNIFICANTLY IMPACTED. THESE WEATHER HAZARDS ARE
ASSOCIATED WITH A VERY WOUND-UP LOW OFF THE OREGON COAST. THE
GREATER IMPACTS ARE SURFACE WINDS AND ABOVE GROUND WINDS
(925MB/~2000 FEET AGL). SURFACE WINDS WILL INCREASE AS THE
PRESSURE GRADIENT GETS TIGHTER; THE ABOVE GROUND WINDS WILL REACH
>60KTS ALONG PORTIONS OF THE COAST; AND THEREFORE PROMOTE THE
POWERFUL THREAT OF LLWS (LOW LEVEL WINDSHEAR). PRECIPITATION
REMAINED MOSTLY LIGHT ACROSS THE REGION THROUGH MUCH OF THE DAY.
HOWEVER, ANOTHER PRONOUNCED WAVE OF RAIN AND EMBEDDED SHOWERS
BEGAN TO INTENSIFY AND SPREAD ACROSS HUMBOLDT AND DEL NORTE
COUNTIES BY MID AFTERNOON. STRONG WINDS HAVE PROBABLY ALLOWED MOST
CIGS TO STAY VFR, BUT THE GROWING RAIN SPREAD IS ALLOWING CIG/VIS
TO DIP INTO MVFR. ADVERSE WEATHER IS EXPECTED TO CONTINUE A
SOMEWHAT UP/DOWN, WALLOPING PATTERN ACROSS THE REGION THROUGH THE
NEXT 24-36 HOURS. A SLIGHT CHANCE OF INCREASED INSTABILITY COULD
EVEN TRIGGER SOME STRONGER CONVECTION. /TA
MARINE
WINDS ARE PEAKING THIS AFTERNOON AS A STRONG LOW SPINS OFF
THE OR/WA COAST. STRONG GALES APPROACHING 40 KNOT GUSTS ARE BEING
OBSERVED IN THE NORTHERN WATERS, WITH SOLID 30 TO 35 KNOT GALE GUSTS
IN THE SOUTHERN WATERS. ALREADY STEEP 10 TO 12 FOOT SHORT PERIOD
WAVES ARE BEING FURTHER REINFORCED BY A LARGE 18-20 FOOT LONG PERIOD
SWELL THAT FILLED INTO THE WATERS LATE THIS MORNING. COMBINED SEAS
APPROACHING 20 TO 23 FEET WILL CONTINUE TO PRODUCE STEEP AND
HAZARDOUS CONDITIONS EVEN AS GALES GRADUALLY PUSH NORTH AND DIMINISH
LATE THIS EVENING. A HIGH SURF ADVISORY WILL REMAIN IN EFFECT
THROUGH EARLY FRIDAY MORNING - SEE THE BEACH HAZARDS SECTION FOR
MORE DETAIL.
GUSTY WINDS AND STEEP SEAS WILL GRADUALLY DIMINISH ON FRIDAY BEFORE
A BRIEF REPRIEVE FROM ADVISORY LEVEL CONDITIONS EARLY THIS WEEKEND.
THERE IS STILL UNCERTAINTY SURROUNDING THE TRACK OF A TIGHT, FAST
MOVING LOW APPROACHING THE WATERS EARLY SUNDAY MORNING. DEPENDING ON
THE STRENGTH AND PROXIMITY OF THE LOW TO THE COAST, LOW END GALES
WILL BE POSSIBLE, ESPECIALLY IN THE OUTER WATERS. NBM STILL ONLY HAS
ABOUT A 30% CHANCE OF SOUTHERLY GUSTS >34 KNOTS BY 11AM SUNDAY. THIS
ACTIVE PATTERN IS EXPECTED TO CONTINUE THROUGH MID-NEXT WEEK.
BEACH HAZARDS
A LARGE WESTERLY SWELL IS CURRENTLY GENERATING 22 TO
24 FOOT BEACH ORIENTED SURF ACROSS AREA BEACHES. A HIGH SURF
ADVISORY WILL REMAIN IN EFFECT THROUGH EARLY FRIDAY MORNING TO
ACCOUNT FOR THESE LARGE BREAKING WAVES AND WAVE RUNUP, WITH ELEVATED
WAVE HEIGHTS PERSISTING THROUGH THE DAY. TAKE EXTRA CARE NEAR
SHORELINE/ WATER'S EDGE AND REMEMBER TO NEVER TURN YOUR BACK ON THE
OCEAN!
EKA WATCHES/WARNINGS/ADVISORIES
CA...
HIGH WIND WARNING UNTIL 11 PM PDT THIS EVENING FOR CAZ101.
HIGH SURF ADVISORY UNTIL 5 AM PDT FRIDAY FOR CAZ101-103-104-
109.
WIND ADVISORY UNTIL 11 PM PDT THIS EVENING FOR CAZ102-
104>106.
WIND ADVISORY UNTIL 8 PM PDT THIS EVENING FOR CAZ103.
WINTER WEATHER ADVISORY UNTIL 8 AM PDT FRIDAY FOR CAZ107.
NORTHWEST CALIFORNIA COASTAL WATERS...
GALE WARNING UNTIL 9 PM PDT THIS EVENING FOR PZZ450-470.
HAZARDOUS SEAS WARNING FROM 9 PM THIS EVENING TO 3 PM PDT
FRIDAY FOR PZZ450-470.
HAZARDOUS SEAS WARNING UNTIL 9 AM PDT FRIDAY FOR PZZ455.
GALE WARNING UNTIL 3 PM PDT THIS AFTERNOON FOR PZZ475.
HAZARDOUS SEAS WARNING UNTIL 9 AM PDT FRIDAY FOR PZZ475.
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