Area Forecast Discussion
Issued by NWS Eureka, CA
Issued by NWS Eureka, CA
783 FXUS66 KEKA 131924 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 1224 PM PDT Sun Jul 13 2025 .SYNOPSIS...Excessive heat is forecast to continue in the interior through Monday. Temperatures and heat risk are forecast to diminish by mid week, but it will still feel hot all week. Isolated dry lightning remains a very remote possibility for the northern Trinity mountains through early next week. && .DISCUSSION... Hot weather continues in the interior, with high temperatures between 100 and 110 likely. The highest temperatures are likely along the Trinity and Klamath Rivers in Trinity and Humboldt Counties. Slightly lower temperatures are found in Mendocino as marine influence increases humidities and lowers temperatures. This heat does bring Moderate to Major HeatRisk and is dangerous to those without proper cooling and those sensitive to heat related illness. Smoke and haze models are showing higher smoke concentrations in the valleys this morning before improving in the afternoon. Greater instability today may help more haze to mix out and better air qualities except immediately downwind from the fires. Models are showing a moisture intrusion coming from the east. Moisture combined with elevated instability may also bring a slight chance (10-15%) for an isolated thunderstorm to northern Trinity County. Model soundings do show a weak capping inversion and moisture remains limited, so confidence remains low. There is a similar setup Monday and Tuesday, but confidence is even lower (5-10% chance for an isolated thunderstorm). The ridge begins to move eastward Tuesday and Wednesday, allowing for the marine layer to deepen and some relief to the hottest temperatures. Temperatures are likely to remain warm, especially in Trinity County, with mid to high 90s, but the consistent triple digits are likely to end. && .AVIATION... Coastal stratus has retreated to the immediate shoreline as inland daytime temperatures increase. Breezy conditions expected again along the coast with westerly gusts 10 to 15 knots possible this afternoon. UKI will remain clear with breezy WNW winds 10 to 15 knots. Increasing northerly winds offshore will help to scour out some of the stratus layer, but a persistent southerly reversal will likely keep cloud cover nearshore and the coastal terminals IFR to LIFR. Brief scattering is possible prior to 00Z, but IFR ceilings are expected to return late this evening (HREF >50%). Strong northerly winds will push closer to the coast overnight into early Monday morning. HREF probabilities for IFR ceilings quickly fall below 50% after 12Z for CEC while ACV may hang onto cloud cover through 18Z. Gusty winds expected through Monday afternoon with >30 knots possible at CEC. && .MARINE... Gale force winds in the northern outer waters will gradually expand southward in coverage this afternoon into Monday, with gusts exceeding 40 to 45 knots likely in NW PZZ470. As these winds push towards the coast, near- gale to gale gusts are possible nearshore of Point Saint George and Cape Mendocino, especially Monday afternoon. Steep and hazardous seas 9 to 14 feet will likely propagate into the inner waters as well. Steep wind driven seas 12 to 16 feet are expected through Tuesday, especially in the outer waters. High pressure will begin to break down Tuesday afternoon, diminishing hazardous conditions by midweek. && .FIRE WEATHER... Building high pressure along with offshore flow has brought warming and drying to the interior and near-coastal areas. Afternoon RHs remain very dry, into the teens and 20s across most the interior. High elevation areas (above 2000-2500 ft or so) continue to see moderate to poor overnight RH recoveries. Lower elevations are largely seeing moderate to good overnight recoveries. Offshore winds in the higher terrain are forecast to remain breezy overnight, especially in Del Norte county, though at least Monday morning. Offshore flow begins to weaken slightly Monday night and Tuesday morning, and more significantly by Tuesday night. Upper-level moisture arrives from the east this afternoon into early next week. Elevated instability along with some moisture brings a slight chance (10-15%) for isolated dry thunderstorms to northern Trinity County. As of now, moisture looks more limited on Monday, but there is still a 5-10% chance for isolated dry thunderstorms. The ridge begins to weaken Monday into early next week, which will slowly deepen the marine layer into the middle of next week. RHs will improve in the near-coastal areas with moderate to good overnight recoveries possible in the highest terrain by the Tuesday or Wednesday. && .EKA WATCHES/WARNINGS/ADVISORIES... CA... Extreme Heat Warning until 11 PM PDT Monday for CAZ102-105- 107-108. Heat Advisory until 11 PM PDT Monday for CAZ106. Heat Advisory until 11 PM PDT this evening for CAZ110-111- 113>115. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 11 AM PDT Monday for PZZ450-475. Hazardous Seas Warning from 11 AM Monday to 11 AM PDT Tuesday for PZZ450-475. Small Craft Advisory from 5 PM Monday to 11 AM PDT Tuesday for PZZ455. Hazardous Seas Warning until 5 PM PDT this afternoon for PZZ470. Gale Warning from 5 PM this afternoon to 11 AM PDT Tuesday for PZZ470. && $$ 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