FXUS66 KEKA 032301 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 301 PM PST Tue Dec 3 2024 .SYNOPSIS...Relatively clear, warm and dry conditions expected through midweek. A weak shortwave will move through the region Wednesday and Thursday, producing light drizzle along the north coast. Chances for rainfall or drizzle increase through the weekend. && .DISCUSSION...With a strong ridge of high pressure firmly in place, overnight lows are forecast to drop to chilly but seasonably normal levels in the lower elevations once again tonight. The ridgetop temperatures will likely be much milder above the inversion. Coastal stratus and fog will begin increasing in coverage tonight. A weak shortwave will clip the region Wednesday night, mainly increasing cloud cover. Some light showers and coastal drizzle will also possible early Thursday morning, but precipitation accumulations will be highly limited with chances for over 0.1 inch of rainfall less than 20%. The ridge will further amplify late this week, and daytime highs will be warm, pleasant and much above climatological averages. There are indications the coastal stratus and it is possible fog will regain more of a presence, and this would suppress high temps for portions of the coast. A stronger system will impact the Pacific Northwest this weekend, with some of it likely clipping N CA. Probabilities for a wetting rainfall over a tenth for an inch go up to 40 to 65%, but significantly drop for over 0.3 inches. Orientation of steering high pressure will determine how much moisture makes it to the coast; elevated PWAT values are available just offshore within a weak AR-type feature. 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...VFR conditions with abundant clear skies prevail across all TAF terminals this afternoon. Some tempo IFR visibility reduction in mist is expected once again for KCEC later this evening. HREF model guidance indicate a shallow marine layer developing along the coast late tonight trough Wednesday. As a result, some low clouds and visibility reduction in mist/fog are possible along the coastal terminals. HREF visibility probability indicates there is a 30-40% chance for visibility below 4SM, while 20-30% chance below 5SM per NBM. Meanwhile, VFR conditions remain at UKI. && .MARINE...Gentle to moderate northerly breezes have developed across the coastal waters, with locally gusty winds up to 25 kts downwind of Cape Mendocino this afternoon through early Wednesday. Followed by light to gentle W-NW breezes. Winds will shift to S north of Cape Mendocino Wednesday night as a weak frontal system moves through. On Thursday, northerly winds will redeveloped, with moderate to fresh breezes possible south of Cape Mendocino. A short-period N wave at 4 to 5 feet are expected to subside Wednesday afternoon. A long-mid period W swell will continue to decay through Wednesday morning, followed by mid-period W swell will arrive Wednesday afternoon and will peak late Wednesday night and early Thursday at 6 feet. A forerunner of W well 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