913  
FXUS66 KEKA 211228  
AFDEKA  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE EUREKA CA  
428 AM PST FRI FEB 21 2025  
   
SYNOPSIS
 
DRY AND WARMER WEATHER CONTINUES TODAY. CHANCE OF  
RAIN RETURNS THIS WEEKEND AND CONTINUES INTO EARLY NEXT WEEK.  
GUSTY SOUTHERLY WINDS EXPECTED ALONG THE NORTH COAST AND OVER THE  
INTERIOR MOUNTAINS THIS WEEKEND AND EARLY NEXT WEEK.  
 

 
   
DISCUSSION
 
SATELLITE IMAGERY SHOWED VARIABLE HIGH THIN CLOUDS  
MOVING ACROSS THE AREA THIS MORNING. PATCHES OF FOG AND LOW CLOUD  
COVER WERE ALSO APPARENT UNDERNEATH THE CIRROSTRATUS. MORE HIGH  
AND PERHAPS MID CLOUDS OFFSHORE WILL LIKELY SPREAD OVER THE AREA  
THROUGH TODAY. RIDGE ALOFT WILL DOMINATE AND NO RAIN IS EXPECTED.  
EVEN TONIGHT HIGH RESOLUTION MODEL GUIDANCE CONTINUES TO INDICATE  
VERY LITTLE OR NO RAIN FOR THE AREA, THOUGH CAMS SHOW A FEW LIGHT  
SHOWERS OR SPRINKLES POSSIBLE TONIGHT.  
 
A LONG FETCH OF DEEP LAYER MOISTURE EMANATING FROM THE SUBTROPICS  
(PWATS OVER 1 INCH) 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 AND FAR NORTHERN HUMBOLDT. 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 WITH  
LOWER PROBABILITIES FOR AR3). EXPECT MOSTLY BENEFICIAL RAINFALL.  
MINOR NUISANCE FLOODING IS POSSIBLE WITH THE HEAVIER RAINFALL  
SATURDAY NIGHT INTO EARLY SUNDAY. MUDSLIDES WILL ALSO BE POSSIBLE  
IN THE STEEP TERRAIN ON HIGHWAY 199 IN DEL NORTE COUNTY SATURDAY  
NIGHT WHEN THE HEAVIEST RAIN RATES OCCUR.  
 
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 SURFACE LOW IS FORECAST  
TO DEVELOP JUST OUTSIDE 135W NORTH OF 40N ON MONDAY AND STRONGER  
WIND GUSTS TO 50 MPH ARE POSSIBLE FOR THE COASTAL HEADLANDS AND  
INTERIOR RIDGES AS THE PRESSURE GRADIENT TIGHTENS AND A 925MB  
SOUTHERLY 50KT+ SPEED MAX DEVELOPS ALONG THE COAST IN ADVANCE OF  
A FRONTAL BOUNDARY. THE EXACT TIMING REMAINS UNCERTAIN, THOUGH THE  
ECMWF HAS BEEN CLUSTERING AROUND MONDAY AFTERNOON/EVENING WITH  
ENSEMBLE MEAN GUSTS NEAR 50 MPH FOR PT ST GEORGE AND KCEC AIRPORT.  
LOOKING THE NBM, 90TH PERCENTILE MAX GUSTS ARE ON THE ORDER OF 55  
TO 65 MPH OVER THE INTERIOR MOUNTAINS OF DEL NORTE WITH LOWER  
PROBABILITIES FOR GUSTS OVER 50 MPH FOR THE HUMBOLDT INTERIOR  
MOUNTAINS; KNEELAND AND BERRY SUMMIT. WIND THIS STRONG WILL MAKE  
DRIVING DIFFICULT AND COULD KNOCK DOWN TREE BRANCHES.  
 
PRECIP SHOULD START TO END ON TUE AS BROAD UPPER RIDGING QUICKLY  
SPRINGING BACK AND HOLDS INTO MID WEEK (WED). THE RIDGE ALOFT  
WITH ABOVE NORMAL 500MB HEIGHTS WILL LIKELY REMAIN THE DOMINANT  
FEATURE CONTROLLING NW CALIFORNIA WEATHER INTO LATE NEXT WEEK.  
TEMPERATURES WILL LIKELY REMAIN ABOVE NORMAL. DB  
 

 
   
AVIATION
 
OFFSHORE FLOW HAS KEPT VFR CONDITIONS AT THE TERMINALS,  
WITH LOW CLOUD CONSTRAINED TO SOME OF THE RIVER VALLEYS EARLY THIS  
MORNING. SOME BRIEF IMPACTS FROM SHALLOW MIST/FOG IS POSSIBLE AT ALL  
THE TERMINALS BEFORE/AROUND SUNRISE, BUT CONFIDENCE IS LOW. ANY LOW  
CLOUD THAT DOES FORM WILL LIFT AND SCATTER OUT SHORTLY AFTER  
SUNRISE. HREF IS HINTING AT STRATUS FORMING OFFSHORE THIS AFTERNOON,  
AND ONSHORE FLOW COULD PUSH THIS INTO THE COASTAL TERMINALS. A WEAK  
SHORTWAVE COULD BRING A BRIEF SPRINKLE TO CEC THIS EVENING, AS WELL.  
WHILE CONFIDENCE IS NOT HIGH ON SEEING STRATUS (LESS THAN 30% PROBABILITIES).  
IF ANY DOES PUSH ON SHORE, THE SHORTWAVE COULD WEAKEN THE SURFACE  
INVERSION TO RESULT IN IFR/MVFR CEILINGS RATHER THAN LIFR. REGARDLESS,  
RAIN CHANCES INCREASE TONIGHT INTO SATURDAY. JB  
 

 
   
MARINE
 
RELATIVELY LIGHT WESTERLY WINDS ARE EXPECTED TODAY AS HIGH  
PRESSURE WEAKENS, BUT SEAS REMAIN ELEVATED AS A FRESH LONG-PERIOD  
WESTERLY SWELL BUILDS IN, BRINGING COMBINED SEAS OF 8-12 FT. WINDS  
TURN SOUTHERLY AHEAD OF A FRONT OVERNIGHT INTO SATURDAY. SIGNIFICANT  
INCREASES IN WINDS ARE EXPECTED NORTH OF CAPE MENDOCINO, WITH STRONG  
BREEZES TO NEAR-GALE FORCE GUSTS FORECAST SATURDAY AFTERNOON. SOUTH  
OF CAPE MENDOCINO, WINDS REMAIN RELATIVELY LIGHT SATURDAY WITH  
GENTLE TO MODERATE BREEZES EXPECTED.  
 
WINDS SUNDAY REMAIN ELEVATED IN THE NORTHERN WATERS AND INCREASE  
SLIGHTLY IN THE SOUTHERN WATERS TO MODERATE TO FRESH BREEZES. NEAR-  
GALE FORCE GUSTS ARE POSSIBLE IN THE NORTHERN WATERS AGAIN SUNDAY  
AFTERNOON. SEAS THROUGH THE WEEKEND WILL BE CHARACTERIZED BY  
SOUTHERLY WIND WAVES AND FURTHER LONG-PERIOD WESTERLY SWELLS. WINDS  
FURTHER INCREASE MONDAY AS A FRONT MOVES THROUGH, WITH GALES  
POSSIBLE NORTH OF CAPE MENDOCINO. JB  
 

 
   
BEACH HAZARDS
 
A WESTERLY SWELL PEAKING AROUND 9-12 FT AT 16  
SECONDS BUILDS INTO THE WATERS TODAY. WITH LIGHT WINDS AND MILD  
WEATHER EXPECTED, 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 THROUGH LATE TONIGHT FOR CAZ101-103-  
104-109.  
 
NORTHWEST CALIFORNIA COASTAL WATERS...  
SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 3 PM PST  
SUNDAY FOR PZZ450.  
 
SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 3 PM PST  
SATURDAY FOR PZZ455.  
 
SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 3 PM PST  
SUNDAY FOR PZZ470.  
 
SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 3 PM PST  
SATURDAY FOR PZZ475.  
 

 
 

 
 
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