Area Forecast Discussion
Issued by NWS Eureka, CA
Issued by NWS Eureka, CA
155 FXUS66 KEKA 092041 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 1241 PM PST Sun Nov 9 2025 .SYNOPSIS...Above normal temperatures and dry conditions will persist through Tuesday with night and morning valley and coastal fog. Wet and unsettled weather conditions will impact the area starting mid to late in the day on Wednesday. This will bring heavy rain and wind Wednesday night. Thursday snow levels are expected to drop as low as 4,000 feet with additional precipitation. && .DISCUSSION...High pressure continues over the area with a weather system moving by to the north of the area. This once again brought fog to the valleys, although it was not as widespread as yesterday morning. This is expected to continue to keep temperatures cooler than the NBM model guidance in the valleys. Afternoon highs will still be above normal and likely a few degrees warmer than yesterday. This pattern is expected to continue Monday and Tuesday mornings. As it continues to dry out there is an outside chance for some frost in the colder valleys Monday and Tuesday mornings, but at this point it doesn`t look too likely. Tuesday night into Wednesday the next weather system starts to approach the area. South to southeast winds are expected to start to increase overnight and this may help diminish fog and low clouds. Current models show the rain starting after 18Z (10AM) Wednesday in most areas. More likely it will start closer to early or mid afternoon. A period of moderate to heavy rain is expected from Wednesday evening through Thursday morning. One to three inches of rain is expected early Thursday morning. Integrated Vapor Transport (IVT) values remain fairly strong, there is still a 50 to 60 percent chance of exceeding 500 kg/m/s. This may be enough to generate some flooding of poor drainage and low lying areas, but not much beyond that. Once again the rivers are not expected to see much of a rise. Strong winds are expected with this system, the GFS has low level jet at 925 mb around 50 to 60 kt off the coast. There is some ensemble support for this, but the clusters show fairly big discrepancies making confidence low on the winds. Gusts of 40 to 50 mph are expected in wind prone areas with local gusts to 60 mph possible on the ridges. Thursday afternoon and into the evening the upper level trough is expected to move overhead bringing showers to the area and lower snow levels. Rainfall amounts are expected to be lighter with this showers, although a few on the north coast could produce locally heavy rain. This colder storm will bring the potential for lower snow levels. Currently the models show them dropping to around 4,000 feet and possibly a bit lower. Currently this is expected to be above the main highway passes except for Hwy 3 at Scott Mountain summit which could see several inches of snow. This will likely bring snow to many of the higher elevation areas including Horse mountain in Humboldt county. Friday snow levels are expected to start to rise as high pressure starts to build in. There may be some light rain or snow produced by overrunning as this builds into the area. Generally drier weather is expected on Saturday before another system starts to move into the area on Sunday. MKK && .AVIATION...18z TAF...Isolated and shallow ground fog today quickly gave way to widespread calm and clear VFR conditions all across the area. VFR conditions will continue well into the evening hours. A weak trough passing to the north may encourage a weak, shallow marine layer to form overnight. Such a layer would bring LIFR ceilings near the coast. Any marine layer would be localized with chances greatest (40% chance) around Crescent City and less (20% chance) around Humboldt Bay. If a marine layer does form, it could persist through much of Monday morning before lifting later in the day. /JHW && .MARINE...Mild conditions continue today with a decaying mid period swell now below 6 feet being the only notable feature. Otherwise, calm northerly winds will be too weak to generate any short period seas, helping to create an unusually calm sea state through early Monday morning. Moderate northerly winds will build in the southern waters Monday afternoon and slowly spread north by Tuesday, most likely building short period seas back above 6 feet alongside continuing. In addition, a renewed mid period westerly swell will begin to arrive early Monday, building back above 8 feet. Moderate conditions will continue through early Wednesday. Much steeper seas will return late next week as another storm system most likely (70% chance) brings gale force southerly winds late Wednesday into Thursday. /JHW && .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