723 FXUS66 KEKA 012129 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 229 PM PDT Sat Apr 1 2023 .SYNOPSIS...Showers will increase in coverage and intensity tonight through Sunday. In addition, periods of light to moderate snowfall will impact mountain roads and passes in Del Norte and Humboldt Counties. Otherwise, gusty north winds will develop across the region during Monday morning. Light showers will remain possible Tuesday through Thursday, followed by potentially warmer and drier weather next weekend. && .DISCUSSION...Cool northwesterly flow aloft was occurring over the West Coast this afternoon, while in the low-levels, a shallow moist layer was promoting occasional drizzle and showers in NWRN CA, particularly across the coastal foothills. During the next 24 hours, an upper-level shortwave trough is forecast to progress east across the NERN PAC. That feature will aid in deepening the moist layer, and cooling temperatures aloft will also steepen lapse rates. Showers will subsequently increase in coverage and intensity, particularly across Del Norte and Humboldt Counties. In addition, snow levels situated between 2000 to 2500 ft MSL will favor light accumulations across the higher ridges and passes in Del Norte and Humboldt Counties. Some travel impacts may occur along portions of HWY 199, 299, and 36 due to 2-4 inches of snow accumulation between 5 AM to 11 PM Sunday. A winter weather advisory has been issued as a result. The previously mentioned shortwave is forecast to exit east on Monday, but model guidance shows post-trough showers lingering across NRN CA. In addition, north-northwesterly winds may gust from 20 to 30 mph during part of Monday. Otherwise, minor upper disturbances are forecast to impact the West Coast Tuesday through Thursday, and will aid in additional shower generation. Multi- model guidance then signals ridge amplification next weekend into early next week, which would favor warmer and drier weather across much of the WRN CONUS. Garner && .AVIATION...A weak frontal boundary is moving across the area bringing MVFR to IFR conditions due to light rain and drizzle this afternoon. The front is moving from northwest to southeast and areas behind the front are already seeing CIGs lifting and MVFR to IFR conditions. CIGS will continue to gradually improve this afternoon before another boundary starts to move onshore dropping conditions once again this evening and tonight as it moves in from the northwest. This will lower CIGs and vis again in the rain showers, likely to MVFR with periods of IFR. Clouds will start to diminish again through the day Sunday behind this boundary. MKK && .MARINE...Winds and seas have diminished as the front has moved inland today and winds have turned west to northwest this afternoon. The winds remain around 5 to 10 kt tonight so will allow the small craft advisory to expire this afternoon. This will bring some 2 to 3 foot wind driven waves with it. In addition, tonight a northwest swell is expected to move into the area and slowly build to around 5 to 6 feet at 12 seconds. Sunday northwest winds are expected to gradually increase through the day to around 15 to 20 kt by late in the afternoon. A small craft advisory will likely be needed as these pick up again. Monday these northwest winds and associated seas will remain elevated before diminishing on Tuesday ahead of another system. The northwest swell is expected to build again on Monday to around 7 to 10 feet at 11 seconds. This is expected to drop to 6 to 8 feet on Tuesday. Mid to late in the week another system is expected to bring moderate to strong southerly winds and an additional frontal boundary, however there is still a lot of uncertainty in the strength and timing of this. In addition a small northwest swell is expected to slowly diminish through the week. MKK && .EKA WATCHES/WARNINGS/ADVISORIES... CA... Winter Weather Advisory from 5 AM to 11 PM PDT Sunday for CAZ102-105-106. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 3 PM PDT this afternoon for PZZ450-470. && $$ 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