182  
FXUS66 KEKA 191132  
AFDEKA  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE EUREKA CA  
432 AM PDT FRI APR 19 2024  
   
SYNOPSIS
 
ABOVE NORMAL AFTERNOON TEMPERATURES WILL CONTINUE ACROSS  
THE INTERIOR VALLEYS INTO EARLY NEXT WEEK. A WEAK COLD FRONT WILL  
BRING A SLIGHT CHANCE OF LIGHT RAIN AND DRIZZLE TO THE NORTH COAST  
ON SATURDAY FOLLOWED BY BREEZY NORTHERLY WINDS ON SUNDAY.  
 

 
   
DISCUSSION
 
PICS FROM SKY DEPICTS HIGH CLOUDS CONTINUES  
STREAMING ACROSS NORTHERN CALIFORNIA THIS MORNING, WHILE SOUTHERLY  
WIND REVERSAL AIDED COASTAL STRATUS MOVING NORTHWARD REACHING THE  
SOUTHWESTERN PORTION OF MENDOCINO COAST. OVERNIGHT TEMPERATURES  
HAVE BEEN RUNNING 3 TO 8 DEGREES WARMER COMPARED TO LAST NIGHT.  
 
UPPER LEVEL RIDGE WEAKEN SLIGHTLY AND IS EXPECTED TO SHIFT  
EASTWARD TODAY THROUGH SATURDAY. EXPECT ANOTHER PLEASANT DAY WITH  
ABOVE NORMAL TEMPERATURES TO CONTINUE ACROSS THE INTERIOR VALLEYS  
TODAY. INTERIOR TEMPERATURES ARE FORECAST TO BE FEW DEGREES  
WARMER COMPARED WITH YESTERDAY'S READING, WITH HIGHS IN THE UPPER  
70S TO MID 80S. COASTAL AREAS ARE EXPECTED TO BE NEAR NORMAL  
TEMPERATURES, WITH HIGHS FORECAST IN THE 50S. HREF GUIDANCE  
INDICATED LOW STRATUS CLOUDS CHARGING UP ALONG AND LAPPING THE  
MENDOCINO COAST THROUGHOUT THE DAY, AND FORMING OFFSHORE OVER THE  
WATERS AND SPREAD ONTO THE NORTH COAST TONIGHT IN ADVANCE OF A  
WEAK FRONT.  
 
A WEAK FRONT ASSOCIATED WITH A TRANSIENT SHORTWAVE TROUGH WILL  
BRING A PUSH LOW LEVEL MOISTURE AND PERHAPS SOME LIGHT RAIN AND  
DRIZZLE TO DEL NORTE AND NORTHERN HUMBOLDT COUNTIES, PRIMARILY  
DURING THE AFTERNOON ON SATURDAY. OTHERWISE, DRY WEATHER AND SOME  
COOLING OF INTERIOR HIGH TEMPS ARE EXPECTED IN RESPONSE TO BREEZY  
WEST-NORTHWEST WINDS AND GREATER CLOUD COVER ACROSS THE INTERIOR.  
 
SURFACE HIGH PRESSURE WILL BUILD IN QUICKLY OVER THE PACIFIC  
NORTHWEST SATURDAY NIGHT AND SUNDAY IN THE WAKE OF THE FRONT.  
BREEZY NORTHERLY WINDS ARE FORECAST TO REDEVELOPED OVER MOSTLY  
COASTAL AREAS AS SURFACE PRESSURE GRADIENTS TIGHTEN ON SUNDAY.  
NBM PROBABILITIES INDICATES A 60-80% CHANCE FOR WIND GUSTS FROM  
30-40 MPH ALONG THE EXPOSED RIDGES AND COASTAL HEADLANDS OF DEL  
NORTE/HUMBOLDT COUNTIES ON SUNDAY. ALSO, GUSTY WEST-NORTHWEST  
WINDS WILL MOST LIKELY DEVELOP THROUGH CHANNELED TERRAIN IN THE  
INTERIOR BEHIND THE FRONT SATURDAY EVENING.  
 
AFTER A BRIEF PERIOD OF INTERIOR WARMING AND UPPER RIDGING, INTERIOR  
TEMPERATURES ARE FORECAST TO TREND DOWN MID TO LATE NEXT WEEK AND  
MORE SEASONABLE VALUES AS ANOTHER UPPER-TROUGH-COMPLEX IMPACTS  
THE WEST COAST. THE MAGNITUDE AND RATE OF COOLING REMAINS HIGHLY  
UNCERTAIN AT THIS POINT WITH 25-75TH SPREADS ON THE ORDER 10F FOR  
HIGH TEMPS AND 5F FOR LOW TEMPS. CURRENT FORECAST IS FOR NEAR  
NORMAL TEMPERATURES; HIGHS IN THE 60S AND LOWS MOSTLY IN THE 40S.  
THERE ARE SUBTLE INDICATIONS FOR CONVECTION ACROSS MAINLY TRINITY  
COUNTY ON TUESDAY AS AN UPPER TROUGH WITH LIMITED MOISTURE  
GENERATES INSTABILITY.  
 
POTENTIAL FOR PRECIP (SHOWERS) WILL ALSO INCREASE MID TO LATE NEXT  
WEEK, THOUGH AMOUNTS WILL MOST LIKELY WONT BE VERY MUCH WITH RAW  
ENSEMBLE PROBABILITIES OF 20% TO 30% FOR > 1 INCH OF RAIN IN  
24-HOURS FOR THE WESTERN SLOPES OF DEL NORTE AND NORTHERN  
HUMBOLDT. STAY TUNED. ZVS/DB  
 

 
   
AVIATION
 
VFR CONDITIONS AND LIGHT OFFSHORE WINDS AGAIN THIS MORNING  
BENEATH A RIDGE OF HIGH PRESSURE AND SCATTERED CIRRUS. A MARINE  
STRATUS SHIELD OBSERVED ON SATELLITE SOUTH OF POINT ARENA IS  
EXPECTED TO MIGRATE NORTH THIS AFTERNOON, BUT SHOULD REMAIN SOUTH OF  
CAPE MENDOCINO. DIURNALLY DRIVEN WINDS WILL PRODUCE WESTERLY WINDS  
ALONG THE COAST AND NORTHERLY UPSLOPE FLOW AT UKI THIS AFTERNOON  
BEFORE RETURNING TO LIGHT OFFSHORE FLOW. COASTAL SOUTHERLY FLOW  
REVERSAL WILL BECOME MORE SUBSTANTIAL TONIGHT INTO SATURDAY MORNING,  
ENHANCED FURTHER BY AN APPROACHING FRONTAL BOUNDARY. HREF INDICATES  
A STRONG MARINE STRATUS SIGNATURE ROUNDING THE CAPE DURING THIS  
PERIOD, HIGHLIGHTING THE POTENTIAL FOR MIST/FOG AND THICK LOW LEVEL  
STRATUS AT THE COASTAL TERMINALS. STRATUS MAY PRODUCE MVFR/IFR  
CEILINGS REDUCED VISIBILITIES BEFORE THE FRONT CROSSES THE COAST  
SATURDAY AFTERNOON.  
 

 
   
MARINE
 
SEAS CONTINUE TO DIMINISH ADMIST LIGHT NORTHERLY WINDS AS  
THE LAST OF THE SMALL CRAFTS EXPIRE IN THE NORTHERN OUTER WATERS.  
LIGHT WINDS AND A SMALL LONG PERIOD SWELL ENSURE CALM SEAS THROUGH  
SATURDAY, WITH WAVE HEIGHTS FALLING TO 2-4 FEET. WINDS WILL BRIEFLY  
TURN SOUTHERLY AHEAD OF A WEAK FRONTAL PASSAGE SATURDAY AFTERNOON  
BEFORE A SWIFT RESURGENCE OF NORTHERLY WINDS BEHIND THE BOUNDARY  
OVERNIGHT INTO SUNDAY. NBM IS STILL INDICATING 80-90% PROBABILITIES  
OF >34 KT GUSTS DEVELOPING DOWNWIND OF CAPE MENDOCINO BEFORE  
EXPANDING TO THE NORTHERN AND SOUTHERN WATERS BY SUNDAY AFTERNOON.  
RESPONSIVE WIND WAVES ALONGSIDE A LONG PERIOD NW SWELL WILL PRODUCE  
STEEP AND HAZARDOUS SEAS EXCEEDING 10 FEET BY LATE SUNDAY. THE  
TIGHTENING PRESSURE GRADIENT DEVELOPING AHEAD OF ANOTHER OFFSHORE  
RIDGE WILL ENABLE GALE WINDS TO CONTINUE IN THE OUTER WATERS THROUGH  
MONDAY MORNING, FURTHER ENHANCING THE SEA STATE TO WAVE HEIGHTS 12  
TO 14 FEET. UNCERTAINTY REMAINS AS TO HOW QUICKLY THE AXIS OF  
ELEVATED WINDS WILL RETREAT OFFSHORE BEFORE ANOTHER TROUGH COMPLEX  
APPROACHES THE PNW ON TUESDAY.  
 

 
   
EKA WATCHES/WARNINGS/ADVISORIES
 
 
CA...  
NONE.  
NORTHWEST CALIFORNIA COASTAL WATERS...  
NONE.  

 
 

 
 
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.

The Nexlab CA Page Main Text Page