Area Forecast Discussion
Issued by NWS Eureka, CA
Issued by NWS Eureka, CA
346 FXUS66 KEKA 022158 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 258 PM PDT Thu May 2 2024 .SYNOPSIS...Mainly dry weather is expected for tonight and Friday. A colder storm with will generate moderate to heavy rain Friday night through Saturday morning. Drastically colder temperatures and light snow are expected for the mountains above 3500 feet on Saturday. Mainly dry conditions and below normal temperatures are expected next week. && .DISCUSSION...A weak cold frontal boundary brought some light rain to Humboldt and Del Norte counties this morning. This evening and tonight mainly dry weather is expected as some shortwave ridging moves over the area and this will continue into Friday. Some drizzle may linger this evening along the Humboldt coast north of Cape Mendocino. It looks like there will continue to be clouds around, especially in the north and along the coast. Friday an upper level low dropping down from the gulf of Alaska. This will bring a cold front to the area and a period of moderate to heavy rain Friday night and early Saturday. Current NBM is now showing widespread 1 to 2 inches of rain. The NBM is showing a 50 percent chance of over 3 inches in the mountains of Del Norte county and in the King range. Southern Lake county and eastern Trinity county valleys may only see a half to three quarters of an inch of rain. Current models show the rain starting mid afternoon Del Norte county and moving south quickly in the late afternoon and evening with rain expected to reach southern Lake county by 10 pm to midnight. Snow levels are expected to drop to around 3500 to 4000 feet. Some of the rain will likely fall ahead of the colder air, but several inches of snow is possible at 4000 feet. The steady rain is expected to come to an end from north of south Saturday morning. Showers are expected in the afternoon. There is some instability and this will bring the potential for thunderstorms in the afternoon. Models are showing CAPE of 100 to 200 j/kg. The NAM is showing some skinny cape in areas along the coast. The question will be if surface temperatures will be warm enough to generate this instability. Saturday night into Sunday morning showers are expected to come to an end, however it looks like clouds will linger over the area. The cold airmass will bring cool temperatures, but with all the moisture around there is not expected to be good radiational cooling. Any valley areas that do clear even briefly will likely see frost or freezing temperatures. However the coldest places will likely be at the higher elevations. 850 MB temperatures are -5C so elevations as low as 2,000 feet may see freezing temperatures even with some cloud cover. Sunday afternoon temperatures will remain chilly with highs in many areas remaining in the 50s. Sunday night through Tuesday the upper level trough is expected to keep some clouds and possible light rain along the Humboldt and Del Norte coasts. This should keep temperatures from getting as cold in these cloudy areas. Farther south and east will likely see near freezing or freezing temperatures. Wednesday drier air is expected to move in and this may be the coldest night some of the valleys and the coast. MKK && .AVIATION...IFR/LIFR conditions are improving slightly as a weak frontal boundary drops south into the CWA, ushering in low to mid level dry air. CEC and ACV will likely scatter out to broken mid- level ceilings and VFR/MVFR conditions this afternoon and evening with some reduced visibilities. Moist westerly flow will gradually weaken and turn offshore (NE) overnight with broken ceilings, warding off widespread fog at coastal terminals. Otherwise, UKI remains quite clear with gusty northerly winds that will diminish this evening beneath scattered high cirrus. LLWS will return overnight as the the BL decouples beneath a shallow inversion. Hi- res models hint at some scattered low level ceilings in the valley, but temperatures will likely have a hard time cooling to saturation. Winds expected to become southerly with increasing cloud cover ahead of a frontal boundary approaching Friday afternoon. && .MARINE...NW winds continue to diminish and turn westerly as a weak front drops into area waters, leaving winds and seas fairly light through the end of this week. Winds will gradually increase and turn southerly ahead of a frontal boundary late Friday, enhancing wave heights to 6-7 feet for the remainder of the weekend. Locally generated NW wind waves will continue to be reinforced by additional frontal passages early next week before a long period swell fills into the waters. && .EKA WATCHES/WARNINGS/ADVISORIES... CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... None. && $$ 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