987 FXUS66 KEKA 090704 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 1204 AM PDT Wed Jul 9 2025 .SYNOPSIS...Near or slightly below normal temperatures are expected again Wednesday. Warming is expected again Thursday with additional warming Friday and hot weather continuing into early next week. && .DISCUSSION...The center of the upper low currently moves over the area. This has the potential to bring some thunderstorms to the area. The models aren`t explicitly outputting thunderstorms, but there is some elevated instability. This, combined with the dynamics of the low and steep lapse rates aloft may bring some nocturnal thunderstorms. Wednesday during the day the upper level low is expected to move off to the east and we will be in northwest flow. It looks like the threat for thunderstorms will diminish through the day light hours on Wednesday. Wednesday night into Thursday morning offshore flow is expected in Humboldt and Del Norte counties. This should diminish the marine layer and allow skies to clear. Thursday is expected to be the transition day with warmer temperatures, but highs are expected to remain in the 90s in most inland areas with low to mid 60s possible along the coast. Friday additional warming is expected with highs climbing over 100 in many of the valleys. The coast may see highs in the middle to upper 60s with continued offshore flow. This is expected to bring moderate to major heat risk to many of the areas. This heat is expected to persist through the weekend in some of the interior areas. A heat advisory may be needed in some of the more persistently hot areas. There is some uncertainty on how much the valleys will cool off at night and that could mitigate the impact of the heat. MKK && .AVIATION...Mostly IFR conditions are expected along the North Coast into Wednesday morning. The upper low spinning over head has aided in the deepening of the marine layer, as well. With southerly flow up the Russian River Valley, there is a possibility of MVFR ceilings for KUKI a few hours before sunrise Wednesday. There appears to be little chance for clearing through the day Wednesday for coastal terminals with ceilings most likely lifting into MVFR range by the afternoon. /JLW && .MARINE...Light winds and low seas are currently dominating the marine environment as an upper low spins over the coastal waters. This low will move inland Wednesday allowing surface high pressure to re-build toward the Northwest California coast over the Eastern Pacific. This will enhance the pressure gradient and once again strengthen the northerlies. Near gale to gale wind gusts are possible Thursday through Saturday, most likely over the outer water zones, pulling into just the northern waters this weekend as the thermal trough builds north over land. Steep short period seas will build in response to the gale northerlies. /RPA && .FIRE WEATHER...High temperatures in the 80`s and 90`s are expected for most of the interior on Wednesday. The marine layer is expected to remain deeper through Wednesday morning as an upper-low moves past the area, bringing slightly higher afternoon RHs. As this upper low moves overhead there is the potential for thunderstorms to move across Humboldt, Del Norte and Trinity counties early Wednesday, yet as of writing this no storms have been seen via satellite/radar. Confidence on these storms manifesting remains low and the better chance for Thunderstorms remains to the north of the area, with storms seen over NE Oregon. Overnight recoveries generally remain good aside from the exposed ridges in the thermal belt. Much hotter temperatures and drier humidity are likely in the interior late this week. Thursday and Friday mornings offshore flow will bring poor recoveries to the higher elevations and may push the stratus off the coast. Triple digit temperatures are likely in most of the interior valleys by Friday with very low afternoon RHs and moderate overnight recoveries. JB && .EKA WATCHES/WARNINGS/ADVISORIES... CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory from 3 AM to 11 AM PDT Thursday for PZZ455-470. Gale Watch from Thursday morning through Thursday evening for PZZ455-470-475. Small Craft Advisory from 9 PM this evening to 11 AM PDT Thursday 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