678 FXUS66 KEKA 100705 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 1205 AM PDT Tue Jun 10 2025 .SYNOPSIS...Isolated thunderstorm threat for Trinity, Del Norte, and NE Mendocino County continues Tuesday afternoon into the evening. Warm temperatures continue Tuesday, however, a cooling trend will keep temperatures cooling steadily through the week into the weekend. && .DISCUSSION...* Isolated afternoon and early thunderstorms in the interior, primarily Trinity County on Tuesday. Cloud-to-ground lightning strikes and gusty erratic winds possible. * Interior heat risk diminishing and becoming low on Wednesday. High temperatures generally decreasing each day this week along with cooler overnight low temperatures late this week. * Gustier afternoon and evening westerly and northwesterly breezes expected mid to late week. An upper level ridge over California will migrate eastward as a weak upper level trough swings over our area from the north. This synoptic weather change will ad variety to our daily weather. First and foremost, there is CAPE aloft over the Klamath mountains, allowing for daytime heating to pop into thunderstorms for one more afternoon. The GFS is showing "Most Unstable CAPE" values centered over Del Norte, Trinity, and Northeastern Mendocino County Tuesday night. Brief wetting rain, cloud to ground lighting, and small (pea- sized) hail is possible with these storms. upper level vorticity will be present in the 700mb level which could help sustain some thunderstorm briefly. However, the storms look relatively dry with the troposphere being at 46% RH by 00Z/5PM. Tuesday has a decreased chance in the NBM probability for thunder with the Trinity Horn area having a 10-20% chance of thunderstorms. Del Norte and NE Mendocino show only a 0-5% chance so confidence remains low for storms developing in those areas. THe majority of the convective development looks to stay much further east of CWA in southern OR and NE CA. Potential for gusty winds and dry lightning could be a fire weather concern for these areas. This incoming trough looks quite dry and main impacts appear to be a return of stronger gusty winds and cooler temperatures. Inland valleys will struggle to break 90F on Wednesday through the rest of the week and weekend. High tempertures look to be around the low 80s at the warmest for inland valleys Friday and Saturday as of right now. This comes a relief after what has been a warm couple of weeks to start meteorological summer. These cooler temperatures will also be accompanied by stronger winds with afternoon wind gusts around 15-20mph in the later portion of the week. && .AVIATION...A strong marine inversion has persisted along the coast and has gradually lowered to LIFR ceilings overnight. Ceilings will most likely continue to drop through the night with short periods of dense fog (50% chance) likely along the coast around sunrise. High resolution models indicate ceilings will be slow to lift along the coast with Humboldt Bay even having a 30% chance of at least IFR conditions persisting all day. The interior, meanwhile, will remain VFR with isolate afternoon thunderstorms over high terrain being the greatest potential concern. /JHW && .MARINE...Gentle northerly winds have continued to spread throughout the waters overnight with short period seas generally below 5 feet. North winds will steadily increase in the outer waters through around midweek with strong wind gusts in the southern outer waters by Wednesday morning. Strong winds will spread north by Thursday with near gale force gusts fanning south of Cape Mendocino. The sea state will be nearly entirely controlled by short period wind waves of 5 to 7 feet around mid week. High pressure stalling over the eastern Pacific will encourage strong northerly winds to continue into the weekend. /JHW && .EKA WATCHES/WARNINGS/ADVISORIES... CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory from 9 PM this evening to 9 PM PDT Wednesday for PZZ475. && $$ 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