Area Forecast Discussion
Issued by NWS Eureka, CA
Issued by NWS Eureka, CA
470 FXUS66 KEKA 161159 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 459 AM PDT Thu May 16 2024 .SYNOPSIS...Temperatures will cool into the weekend with gusty north wind pushing onshore in the afternoon. Coastal stratus and fog will most likely return along much of the coast each night through Friday. && .DISCUSSION...Skies have remained mostly clear overnight, allowing for another round of cool temperatures down into the 50s across the area. That said, offshore wind has been gradually weakening, allowing for shallow fog and marine stratus to gradually appear on satellite, especially around Humboldt Bay. A shortwave passing over the Pacific Northwest today and Friday will help push gusty northerly wind onshore (gusts 10 to 20 mph most likely right along shore). While onshore flow will help support more extensive stratus and fog overnight, it will disrupt surface high pressure. Weaker high pressure will support a gradually cooling trend and only a very weak marine inversion that will most likely mix out each afternoon. The trough over the Pacific Northwest will continue to deepen through the weekend, allowing for interior tempertures to drop below average. This will brings highs in the 70s by Saturday and Sunday. This pattern will also allow for a deeper, though diffuse, marine layer. Such a pattern could generate very light coastal drizzle (10% chance) most likely Friday or Saturday morning. Essentially all ensemble members show a generally troughy pattern continue into next week which will allow below normal temperatures to persist. Increasingly deep troughs will allow for more moisture to be pulled across the area. Though the vast majority of models show little chance (less than 20% chance) of wetting rain, some showers and thunderstorms are certainly possible over high terrain by mid next week. /JHW && .AVIATION...Gusty northerly winds are slowly beginning to decouple from the surface layer, delaying marine stratus development at CEC this morning. Hi-res models beginning to verify the progression of stratus development at ACV and broken ceilings at CEC amidst a southerly wind reversal reaching around the Cape along the Humboldt and Del Norte coasts. NBM indicates >80% probability for <1,000 foot ceilings and IFR visibility`s at ACV between 5 and 8 am this morning. Clouds expected to scatter out by early afternoon along the north coast with increasing northerly winds and daytime heating. Similarly, IFR ceilings creeping up UKI valley this morning will likely persist through the early morning before offshore winds briefly turn northerly this afternoon. && .MARINE...Northerly gales expected to continue in the northern outer waters through the end of the week, producing 10 to 14 foot short period waves across the outer waters as gusts waver in intensity and distribution. Conditions will be slightly moderated lee of the Cape down to Point Arena as the inner waters are sheltered from the strongest winds. HREF currently indicating peak gusts of 35-45 knots possible Friday night into Saturday across the outer waters, producing significant wave heights exceeding 15 feet at 10-11 seconds. Steep and dangerous seas will continue through at least late this weekend - long range models vary on the continuation of gales in the southern waters as the orientation of offshore high pressure shifts. && .EKA WATCHES/WARNINGS/ADVISORIES... CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Hazardous Seas Warning until 3 PM PDT Friday for PZZ450. Gale Warning until 3 AM PDT Saturday for PZZ470. Hazardous Seas Warning until 3 AM PDT Friday 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