Area Forecast Discussion
Issued by NWS Eureka, CA
Issued by NWS Eureka, CA
551 FXUS66 KEKA 250715 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 1215 AM PDT Tue Aug 25 2026 .KEY MESSAGES... * Gradual cooling this week with inland temperatures returning to near or slightly below seasonal normals. * Increasing Relative Humidity and a deeper marine layer will diminish the fire danger this week. && .SYNOPSIS...An upper level trough approaching the Pacific Northwest is expected to start bringing cooler temperatures and a deeper marine layer to the area. The near coastal areas are expected to start cooling today and Wednesday with more cooling late in the week farther inland. && .DISCUSSION...An upper level trough is in place off the Pacific Northwest. This is expected to stall here with shortwaves occasionally rotating around it. The first one is expected to start some minor changes to the weather. This is expected deepen the marine layer and potentially bring some drizzle to the coast this morning. Areas in the "near coastal" zone are expected to see some cooling today with more marine influence. The coast may see brief periods of clearing this afternoon, although generally the status at the immediate coast is expected to be stubborn. Additional shortwaves continue to move around the trough to the northwest of the area. This may bring some subtle changes to the weather each day, but overall the pattern is expected to remain fairly persistent through the work week. The northerly winds will start to increase slightly Thursday, especially along the Mendocino Coast. Next weekend some offshore flow and brief warmup is possible before the trough takes hold again. MKK && .AVIATION...IFR with locally LIFR conditions are in place this morning. The marine layer is gradually getting deeper and this should keep the CIGS and VIS from getting too low this morning. There may some drizzle at times, but this isn`t expected to drop conditions significantly. Ukiah is expected to remain clear, although a clouds will be pushing north from Sonoma county so a few hours of clouds around sunrise are not out of the question. This afternoon CIGs are expected to lift to MVFR conditions at the coast, but clouds likely remain in place for the majority of the afternoon. Tonight clouds are expected to push back inland at the coast, but again expect CIGS won`t get too low. MKK && .MARINE...Winds have diminished along the coast and some local areas have become southerly. These have reached 10 to 15 kt near Pt St George and Crescent City. These local southerly winds will diminish this morning and northerly winds return late this afternoon and tonight. South of Cape Mendocino these may reach 10 to 15 kt with generally 5 to 10 kt farther north. In addition to the local wind driven waves there is a small southerly swell. Currently it is around 2 feet at 14 seconds. This is expected to reinforced with another southerly swell around 2 feet at 17 seconds. Winds are expected to remain fairly steady through Wednesday night. Thursday or Thursday night the northerly winds are expected to increase again to around 15 to 25 kt by Friday afternoon. These are expected to continue to increase over the weekend to 20 to 30 kt. MKK && .FIRE WEATHER...The current weak ridging pattern will give way to a weak troughing regime, bringing cooler temperatures and helping recovery RH values overnight. Minimum daytime RH values will also improve. Trinity Lake county will still have minimum RH values in the upper teens to 20`s Tuesday but will continue to improve as the work week progresses and the offshore low pressure system approaches BC and Washington coast gradually bringing the marine air farther inland as it deeps. Winds will generally remain light and terrain driven, aside from southwesterly afternoon breezes. && .EKA WATCHES/WARNINGS/ADVISORIES... CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... None. && $$ NOTE: The full forecast discussion is now regularly issued between 10 am/pm and 1 pm/am. Additional updates will be issued as needed. 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