973 FXUS66 KEKA 170551 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 1051 PM PDT Sat Apr 16 2022 .SYNOPSIS...Cold overnight temperatures are expected tonight, with freezing temperatures across many areas. Additional periods of rain and high elevation snow are expected Monday and Tuesday and again Wednesday and Thursday. && .UPDATE...Adjusted parts of the Mendocino Coast zone to a freeze warning instead of a hard freeze warning. Temps are running a little milder than expected thus far. The rest of the advisories and warnings remain as issued earlier, though some areas around Ukiah may have a tough time reaching 32 degrees, especially if there continues to be some high cloud cover. && .PREV DISCUSSION... /issued 300 PM PDT Sat Apr 16 2022/ Skies have become mostly clear to partly cloudy across much of the area this afternoon, with mostly cloudy skies lingering across the Del Norte and NE Humboldt interior. These instability clouds will further thin this evening, allowing for areas of freezing temperatures tonight. In fact, some areas will reach hard freeze criteria. N coastal Humboldt county should escape a freeze in most locales, but areas of frost are anticipated. Coastal Del Norte is expected to be above freezing tonight, with too much cloud cover to support frost formation. The evening shift will keep an eye on temperatures through the evening in case they fall more quickly than expected before clouds roll in. Nearly zonal upper flow tonight will be replaced by a digging upstream trough over the E Pacific during Sunday and into Monday. Rain will spread into the area on Monday with some very high elevation snow across E Del Norte and N Trinity counties. Another, stronger upper trough will dig toward the area on Wednesday night and Thursday, with more rain and mountain snow. Snow levels with the second system are expected to be a bit lower along with higher QPF values. As a result, heavier snows are anticipated over N Trinity County along with portions of the Yolla Bollys. This may lead to travel concerns at Scott Mountain Pass. /SEC AVIATION...Northwest California is forecast to experience clearing skies and dryer conditions throughout the next 24 hours as a high pressure system off the coast of central California briefly exerts influence over the region before the next low pressure system approaches. Some cloud cover is still expected along the coast throughout the period. Onshore gentle to light breezes are forecast to occur along the coast into tonight before light and generally north winds dominate overnight. Early tomorrow morning, winds will pick up and turn easterly before turning generally southerly as a low pressure system approaches the Pacific Northwest into Monday morning. VFR conditions are expected throughout the region. Lower visibility and ceilings may occur in some interior valleys just before sunrise due to the lingering moisture from the recent rain. MARINE...North winds over the coastal waters will continue to diminish into tonight. Moderate breezes are forecast to linger in the lee of Cape Mendocino into tomorrow morning. NAMNest in particular indicates that by early tomorrow morning, winds will begin trending southerly in the northern waters and this trend will continue south as the low pressure system to our north moves east toward British Columbia. As the cold front associated with the low approaches the Pacific Northwest, southerlies will intensify in the coastal waters. By Sunday evening, southerlies in the northern outer waters are projected to reach advisory level and by Monday morning, gale level. Near gale sustained winds and gale gusts are forecast to reach the southern outer waters and around the Cape Mendocino Coast by late morning/early afternoon. Winds are projected to cause steep and elevated seas Sunday evening and into late Monday morning, but models indicate that wave heights are expected to stay mostly below 10 feet except in the northern outer waters. Another low pressure system will bring stronger winds to the coastal waters and steep and elevated seas by Wednesday. A defined westerly swell is expected to begin moving through the coastal waters late Monday. Also, a particularly powerful westerly swell is expected to begin moving through the coastal waters by Thursday afternoon at about 14 feet and 17 seconds. && .EKA WATCHES/WARNINGS/ADVISORIES... CA... Freeze Warning until 9 AM PDT Sunday for CAZ102-104-105-109- 112-113-115. Hard Freeze Warning until 9 AM PDT Sunday for CAZ106-108- 110-114. Frost Advisory until 9 AM PDT Sunday for CAZ103. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory from 3 AM to 9 PM PDT Monday for PZZ450. Small Craft Advisory from 6 AM to 9 PM PDT Monday for PZZ455. Small Craft Advisory from 3 PM Sunday to 3 AM PDT Monday for PZZ470. Gale Warning from 3 AM to 3 PM PDT Monday for PZZ470. Small Craft Advisory from 3 AM to 9 AM PDT Monday for PZZ475. Gale Warning from 9 AM to 3 PM PDT Monday 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