


Area Forecast Discussion
Issued by NWS Eureka, CA
Issued by NWS Eureka, CA
632 FXUS66 KEKA 180614 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 1114 PM PDT Fri Oct 17 2025 .SYNOPSIS...Slight warming and drying will peak Saturday with mostly clear skies. Cooler weather and very light coastal rain is expected Sunday with warmer weather again early next week. && .DISCUSSION...Transient high pressure will continue to peak across the area Saturday, allowing for the hottest interior valleys to reach near 80. A weak, shallow marine layer will persist along the coast. Despite clearer skies, continued high dewpoints have prevented any meaningful frost formation across the interior. A weak upper level trough quickly move across the area on Sunday. This will pool in cooler and more moist air alongside midlevel clouds. Overall moisture advection will be weak, however, supporting only very light rain right along the immediate coast. There has been little change in the forecast with likely rain amounts currently between 0.1 and 0.2 inches in Del Norte County with even 50% of models showing little more than drizzle there. Looking south closer to Humboldt Bay, less than 10% of models show any wetting rain. Weak high pressure and slight warming will most likely quickly reassert itself early next week, though low pressure passing to the southeast will limit the amount of warming with only a moderate chance (50%) of some highs even over 80. Strong offshore flow around the low will likely help better dry conditions compared to the currently high stubborn dewpoints. Widespread patchy frost will be likely (60% chance) Monday morning, especially in Trinity County. There is increasing confidence in long range forecasts that a significant rain event will impact the area late next week. Though high uncertainty remains, NBM already places a 95% chance of wetting rain all the way along the North Coast with an 70% chance of 3 day rainfall over 3 inches and a 25% chance of 3 day rainfall over 5 inches. Despite these high totals form the NBM, ensemble spreads remains very large, indicating great potential for lower end scenarios to still be realized. On the stronger end, such an event would likely be accompanied by strong wind with such rainfall amounts capable of moderate flood impacts. /JHW && .AVIATION...18/06Z TAFs...IFR to LIFR ceilings around 300-500 feet along the coastal terminals this evening, while visibility variations between 4SM BR to P6SM. Expect lower ceilings and vsby drop to 1/2SM in fog, with a period of 1/4SM in fog possible early Saturday. There is an increasing chance (45-55%) for 1/2SM or less after 12Z Saturday, especially at KACV. Low ceilings are expected to gradually lift and scattered after 18Z. However, microscale eddy may keep the shoreline with low clouds moving in and out, especially in the vicinity of Humboldt Bay. Onshore flow will push back inland the stratus and fog later in the afternoon and evening. For inland areas, including UKI, mainly VFR conditions are expected to prevail with light breezes. /ZVS && .MARINE...Northerly winds will gradually diminish tonight through Saturday. Generally light to moderate breezes is expected by Saturday afternoon, with very light and variable winds nearshore. A long period northwest swell at 2-5 feet at 18-20 seconds continue building across the waters this evening, and peaking to 8-10 feet at 16 seconds Saturday afternoon. Saturday night into Sunday morning, southerly winds will developed briefly across the outer waters as a weak frontal system moves through, before shifting to northerlies Saturday afternoon. Northerly winds increase again on Sunday afternoon and continue strengthening through early next week. Gale strength gusts are forecast around and south of Cape Mendocino Sunday afternoon through Sunday night. Northerly winds will remain somewhat strengthened into mid next week. The northerly wind pattern breaks down thereafter as a strong trough takes aim at the vicinity of N CA. Strong southerly winds are possible Thursday or Friday if this system take a more southerly track. Chances for at least sustained gale strength southerlies and large surf continue to increase through the weekend with modeled potent NE PAC cyclones. A long period west northwest swell will begin trickling in late this afternoon with 20 second period forerunners. This swell will continue building through Saturday afternoon, peaking around 10 ft at 16 seconds. A second larger swell move in late Sunday through Monday, and Breakers may reach 20 feet through that period. Additional large swells are then likely through next week with an active Pacific storm track. /ZVS&JJW && .BEACH HAZARDS...A Beach Hazard Statement is in effect through Saturday evening. A long period westerly swell will currently moving across the waters will peak to 8 to 10 feet at 16 seconds Saturday afternoon. This high energy swell has the potential to bring moderate risk of sneaker waves, especially late afternoon/ early evening on Saturday. Shorter period NW swell of 5-8 ft at 7-9 seconds may initially mitigate the risk during the morning and afternoon hours on Saturday. Sneaker waves are a unique hazard, with many minutes between waves. Pay attention and stay above the high water line and any wet sand to stay safe. If the ground is wet, waves have surged there recently. Stay safe and never turn your back on the ocean! A potentially larger swell is then forecast to move in late Sunday through Monday./ZVS && .EKA WATCHES/WARNINGS/ADVISORIES... CA... Beach Hazards Statement through Saturday evening for CAZ101- 103-104-109. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until noon PDT Saturday for PZZ450-455. Small Craft Advisory until 11 PM PDT Saturday for PZZ470. Small Craft Advisory until 11 PM PDT Sunday 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