Area Forecast Discussion
Issued by NWS Eureka, CA
Issued by NWS Eureka, CA
543 FXUS66 KEKA 131346 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 518 AM PDT Thu Jun 13 2024 .SYNOPSIS...Dry weather expected through the weekend. Interior temperatures are forecast to trend down today and moderate to near seasonal levels this weekend. Much stronger westerly to northwesterly winds are expected in the interior this weekend. && .DISCUSSION...Extensive stratus covered coastal areas north of Cape Mendocino and extended deep into North Coast river valleys this morning. Low clouds were also forming south of Fort Bragg along the Mendocino coast. The low overcast will most likely scour out this afternoon in response to daytime heating and mixing. The clearing may not last very long for the North Coast as damp onshore breezes result in new stratus generation by early this evening. Stratus and marine layer depth will probably increase on Friday in response to a shortwave through that is forecast to move into the Pac NW by Sat. NW winds aloft in the wake of the shortwave should mix down and scour out the low clouds on Sat. It will get windy this weekend. Prime concern heading into the weekend is potential for strong and gusty westerly to northwesterly winds in the interior, particularly in Lake, Trinity and Mendocino due to the low RH`s. Peak gusts from 25 to 35 mph are probable, with lower probabilities for gusts to 40-50 mph. Strongest winds will most likely occur on Sunday with the passage of a 500mb shortwave trough. Windy conditions in the interior will probably continue into Monday. With fine fuels curing, the strong westerly to northwesterly winds will pose a slight risk for rapid spread of grass fires both Sunday and Monday - if ignitions occur. The highest risk will be in Lake and perhaps eastern Trinity and southern Mendocino where fine fuels continue to cure. Interior temperatures are forecast to trend down today through the weekend. Pockets of moderate heat risk persist today in Lake county, otherwise low or no risk is forecast for the weekend into early next week. Slightly cooler air and continued dry conditions with clear skies should result in chilly overnight temperatures once winds decouple. There is a chance (20-40%) for brief morning frost in the colder valleys of Trinity and eastern Humboldt counties this weekend and early next week. This trough is forecast to be relatively dry and right now the potential for any precipitation is quite meager, 5-10% chance for Del Norte late this weekend. Models diverge on the track of the 500mb trough. Minuscule amounts of rain is not impossible for Del Norte and northern Humboldt on Monday. Wetting rain chances are meager with NBM probabilities for greater than 0.10in no more than 13% for Del Norte and northern Humboldt counties. NBM has temperatures remaining near seasonal normals early next week, followed by gradual warming mid to late next week. DB && .AVIATION...Stratus has returned to the coastal terminals early this morning, with IFR ceilings being reported. These could briefly dip down to LIFR around sunrise, before lifting by mid-morning. Winds at the coastal terminals will be breezy this afternoon, especially at CEC, and will ease after sunset. Stratus will likely return tonight, starting first around Humboldt Bay, then advecting toward CEC. UKI will stay VFR today with typical afternoon breezes. JB && .MARINE...Gales force winds gusting up to 40 knots continue in the outer waters early this morning. The sea state remains hazardous with 10 to 13 ft waves at 10 seconds being observed. Some easing is expected this afternoon north of Cape Mendocino. While seas will remain steep, significant wave heights will dip below 10 ft by Friday afternoon. South of Cape Mendocino, gales force gusts will continue in the expansion fan into Friday. Currently, the expansion fan drifts more into the southern inner waters Friday, which could lead to the return of gales near-shore, but these will subside below gales by Friday evening. The threat of gales look low over the weekend although northerly winds will remain breezy. The sea state will continue to be characterized by northerly wind waves and mid- period northwesterly swells through the weekend. JB && .EKA WATCHES/WARNINGS/ADVISORIES... CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Hazardous Seas Warning until 9 AM PDT this morning for PZZ450. Small Craft Advisory until 3 AM PDT Saturday for PZZ455. Gale Warning until 9 AM PDT this morning for PZZ470. Hazardous Seas Warning from 9 AM this morning to 3 PM PDT this afternoon for PZZ470. Gale Warning until 9 AM PDT Friday for PZZ475. && $$ 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