Area Forecast Discussion
Issued by NWS Eureka, CA
Issued by NWS Eureka, CA
619 FXUS66 KEKA 042113 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 213 PM PDT Sat May 4 2024 .SYNOPSIS...A stout front brought rain and slushy snow to elevations above 2500 feet. A cold air mass approaches and could bring thunderstorms and hail to the coast this evening. && .DISCUSSION...A deep upper level trough brought cold fronts through the are this morning. Bands of precipitation have distributed beneficial amounts of rain across the CWA. Over the last 24 hours, accumulations have totaled over 3 inches for coastal Del Norte and Del Norte interior. Klamath has reported 3.39 inches while the interior at Gasquet, 3.18 inches. Arcata airport has reported 2.80 inches while the rest of Humboldt has received around 2 inches. Lesser amounts in Lake county, 0.96 at Konocti and 1.55 inches at Soda Creek. Mendocino has faired well for this time of year with 1.83 at McGuires and 2.44 inches at South Leggett. In summation, we have received beneficial rain and are several magnitudes greater than the normal values for early May. Antecedent rainfall was minimal before this system and so flooding was not an issue. This approaching low has a cold core and could cause wintry weather to extend through the evening. Reports of snow at 2700 feet this morning confirmed the previous forecast snow levels and with model soundings showing instability and southerly flow, thunderstorms and possibly small hail are possible if day heating of the ground supplies lift to the overrunning cold air mass. The winter weather advisory has been extended through this evening for elevations above 2500 feet as wet snow has already been reported and temperatures are expected to drop. Colder to much colder than average tempertures will remain in place through the weekend and into next week. Near freezing to freezing temperatures for some interior valleys are forecast, but expected fog and lingering cloud cover will hold the temperature up for some valleys over the next couple of nights. Zonal flow followed by a weak shortwave on Monday will bring more unsettled weather and drizzle to light rain. A pronounced ridge of high pressure will then begin building in mid to late next week, and there is growing probability for the warmest interior valleys to exceed 85 degrees through that period. /JJW /EYS && .Aviation...Through this TAF period, the region will continue to experience isolated post frontal showers. Winds have also turned more northwesterly. Scattered thunderstorms may be possible this afternoon and evening, as well, with the threat of small hail at the coastal terminals. MVFR to low VFR ceilings can be expected into tonight while showers taper off. Some low level cloud development may occur for the Russian River Valley into early tomorrow morning. && .Marine...After the passage of a cold front this morning, gusty northwest winds will become confined to the southern waters with the potential for thunderstorm development this afternoon. Steep wind waves are expected in response later today through Sunday as lingering showers dissipate. Combined seas today are forecast to be 5-7 feet with 7-9 second periods through the weekend before a long period northwest swell fills in early next week. Strong northerlies combined with another steep northwest swell by Tuesday night or Wednesday may produce combined seas exceeding 10 feet. A few persistent northwest swells for the next several days will play a factor in combined wave height increasing by mid-week. && .EKA WATCHES/WARNINGS/ADVISORIES... CA... Winter Weather Advisory until 5 PM PDT this afternoon for CAZ102-105>108-111. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until midnight PDT tonight 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