Area Forecast Discussion
Issued by NWS Eureka, CA
Issued by NWS Eureka, CA
222 FXUS66 KEKA 041213 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 413 AM PST Wed Dec 4 2024 .SYNOPSIS...Coastal stratus and fog are increasing along the North Coast, but full sunshine above average daytime temperatures will prevail elsewhere. A weak, shortwave will move through the region Wednesday night and Thursday, possibly generating some light showers or drizzle. Chances for rainfall or drizzle increase again through the weekend with a quick passing front. && .DISCUSSION...A strong ridge of high pressure is firmly in place. Daytime highs are warm and above average, with interior valleys reaching the mid 60s to up to 70. Coastal stratus and fog, which has been observed to be dense at times, have developed and will continue increasing in coverage. This will suppress highs for portions of the coast. A weak shortwave will clip the region tonight into Thursday, mainly increasing cloud cover. Some light showers and coastal drizzle will be possible, but precipitation accumulation will be unlikely for most of the area south of the OR border. The ridge will further amplify late this week, and daytime highs will be warm, pleasant and much above climatological averages. A stronger system will impact the Pacific Northwest through the weekend, with some of it likely clipping N CA with the passing of a front. Probabilities for a wetting rainfall over a tenth for an inch go up to 40 to 65% for far North Humboldt and Del Norte counties. There is a 20 chance for over 0.3 inches through Del Norte County Saturday. Chances for lingering showers carry through Sunday. Cluster and ensemble members show strong evidence the trough will then drop into the Great Basin as an inside slider going into next week, and this pattern is favorable for amplified offshore winds. /JJW && .AVIATION...With high pressure continuing to build into Northern California, shallow stratus development is forming along the coast. As of 3:45AM, there is extensive stratus development along the Mendocino Coast and around the Humboldt Bay region. As a result, LIFR to IFR conditions could be likely into mid morning for coastal terminals. However, at both KCEC and KACV, intermittent and light offshore flow could still aid in keeping the stratus off the coast for a time. Reversal southerly flow just along the coast could help bring the extensive stratus at the Mendocino Coast all the way up to the Del Norte Coast through today. By this evening and overnight, the stratus could be widespread along all of the North Coast. Interior valleys will continue to be foggy/misty into mid morning, particularly the Trinity and Eel river valleys. There is a potential for MVFR conditions around KUKI, but models indicate that VFR conditions are expected for most of the forecast period. /JLW && .MARINE...Light to gentle northerly breezes will continue through the middle of the week. Winds will shift southerly north of Cape Mendocino by tonight as a weak frontal system moves through. On Thursday, northerly winds will redevelop with moderate to fresh breezes possible south of Cape Mendocino. A short-period N wave at 4 to 5 feet is expected to subside this afternoon. A long-mid period W swell will continue to decay through this morning, followed by mid-period W swell that will arrive this afternoon and will peak late tonight and early Thursday at 6 feet. A forerunner of the westerly swell trains will traverse the waters through the weekend. && .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