Area Forecast Discussion
Issued by NWS Eureka, CA
Issued by NWS Eureka, CA
042 FXUS66 KEKA 041300 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 412 AM PDT Sat May 4 2024 .SYNOPSIS...A passing cold front will continue to bring periods of heavy rain early this morning, with snow above 2500 feet. A much colder airmass will then settle in behind the front to bring near freezing to freezing temperatures for some interior valleys. && .DISCUSSION...A late season cold front brought widespread heavy rainfall rates up to 0.5 inches per hour overnight, with activity continuing this morning as it moves southward. Soils, creeks, rivers, and gutter systems have handled the water well with non- advisory level issues observed so far. Interior snowfall continues as snow levels are quickly dropping. The Winter Weather Advisory remains for elevations above 2500 feet. A seasonably anomalous, cold upper low will work its way over N CA throughout the day. Associated instability and 700mb temperatures as cold as -13C will bring showers and possibly a thunderstorm, some which could contain small hail through this evening. Colder to much colder than average tempertures will remain in place through the weekend and into next week. Near freezing to freezing temperatures for some interior valleys are forecast, but expected fog and lingering cloud cover will hold the temperature up for some valleys over the next couple of nights. Zonal flow followed by a weak shortwave on Monday will bring more unsettled weather and drizzle to light rain. A pronounced ridge of high pressure will then begin building in mid to late next week, and there is growing probability for the warmest interior valleys to exceed 85 degrees through that period. /JJW && .AVIATION...Biggest problem to deal with to start the forecast will be ceilings in the IFR to MVFR range behind a cold front as wind has shifted to the west. Cold front aloft will play a part in some thunderstorm potential this afternoon and evening, although chances are quite small. Ensembles indicate the chance of MVFR or worse ceilings dips below 50% along the coast by about 21-22Z, and toward 17Z for KUKI. For visibility, the overall trend is for improvement in visibility for all TAF sites, except for some potential that some slight worsening of visibility will occur within the first couple of hours of the forecast. Can`t rule out the potential for small hail accumulation for the coast this afternoon and early evening. We may not completely lose our light rain or drizzle potential through the night tonight and into early Sunday morning. && .MARINE...After strong winds occurred directly behind a passing cold front earlier this morning, gusty northwest winds will become confined to the southern waters by late this morning, with the potential for thunderstorm development. Steep wind wave response expected late today through Sunday as lingering showers dissipate. Combined seas today are forecast to be 5-7 feet with 7-9 second periods through the weekend before a long period northwest swell fills in early next week. Strong northerlies combined with another steep northwest swell by Tuesday night or Wednesday may produce combined seas exceeding 10 feet. A few persistent northwest swells for the next several days will play a factor in combined wave height increasing by mid-week. Small craft advisories are all ending by mid-evening tonight. && .EKA WATCHES/WARNINGS/ADVISORIES... CA... Winter Weather Advisory until 11 AM PDT this morning for CAZ102-105>108-111. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 9 AM PDT this morning for PZZ470. Small Craft Advisory until 9 PM PDT this evening 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