textproduct: Eureka

SYNOPSIS

Showers continue today and begin to taper off tonight. Chilly temperatures likely tonight and Monday night. Rain likely returns by Wednesday. Near freezing or freezing low temperatures are expected late in the week with more rain possible over the weekend.

DISCUSSION

The low pressure has moved on shore and continues to bring spotty showers around the area. A few stronger showers may develop this afternoon, bringing areas of locally heavy rain and thunderstorms. Snow levels briefly dropped as low as 2500 ft in some of the heavier showers, but are expected to rise to 4500 to 5000 ft this afternoon. A Winter Weather Advisory remains in effect until this evening above 5000 ft in Northern Trinity County for continued snow at Highway 3 at Scott Mountain Pass. The low continues to move out of the area this evening and overnight, with showers winding down. By Monday morning, the only shower activity will be light near the coast with one final pulse of moisture. A chilly morning is likely tonight, though valley fog should keep widespread freezing temperatures from occurring. Still, a few of the coldest valleys in Trinity, northern Mendocino, and northern Lake could see frost tonight with temperatures dropping into the mid 30s.

High temperatures Monday will remain generally below normal for the interior, with 50s to low 60s likely for most areas. Frost is possible again Monday night/Tuesday morning as conditions remain dry and lingering cloud cover exists. Still, valley fog may complicate this. Tuesday, temperatures rebound slightly with highs in the low to mid 60s for the warmer valleys, with 50s still likely at the coast.

The next system arriving Tuesday night into Wednesday will is likely to bring a wetting rain at least to Humboldt, Del Norte, and Trinity Counties. NBM shows over a 90% chance for 0.1" for much of Humboldt and Del Norte, with chances above 50% in Trinity and northern Mendocino Counties. Chances drop off sharply into southern Mendocino and Lake Counties. NBM is showing around 60% chances for over an inch in the mountains of Del Norte and around 40% chances on the coast. In Humboldt, chances above 20% are restrained to the mountains and far northern Humboldt. At this time, snow levels look fairly high at around 5500-6000 ft. A cold airmass behind this front moves in as early as Wednesday evening. Depending on timing, this could bring low snow levels for the remaining light showers and could potentially bring a dusting down to lower elevations. If the front moves out earlier and skies clear, widespread near-freezing to freezing temperatures are possible across the area.

Dry weather is expected to close the work week. Near-freezing temperatures are possible again Thursday night into Friday morning, but temperatures start to rebound again Friday afternoon. 70s could return to some of the warmer interior valleys. This will likely be temporary as around 80% of ensemble members show a return of wet weather likely for next weekend. JB

AVIATION

Mostly VFR conditions across the TAF sites, with period of MVFR with VCSH/-SHRA. Shower activity will continue to diminish from north to south throughout the day. Surface winds from W at 5-10 kts, becoming very light and variable after 13/04Z. Tonight into Monday, MVFR ceilings with VCSH/-SHRA is expected for the coastal terminals. Meanwhile, IFR clouds and mist is possible for UKI. /ZVS

MARINE

Wind is swirling over the water due to a passing low- pressure system this afternoon, with light to localized moderate breezes. Mostly gentle west-northwest winds are expected this evening across the waters. A mid-period westerly swell between 5-8 feet will continue to build in through Monday morning.

Monday, northerly winds return as high pressure starts to build into the area. This will promote moderate to fresh northerly breezes across the waters Monday into Tuesday, with the strongest winds south of Cape Mendocino.

Tuesday, winds diminish and gradually shift to south over the northern waters, before strengthen to fresh breezes Tuesday night into Wednesday as a cold front approaches from the North. This will be followed by strengthening northerly winds Wednesday night through Friday as the pressure gradient tighten. There is a high potential (85-100% chances) of gale force gusts Thursday-Friday. /ZVS

EKA WATCHES/WARNINGS/ADVISORIES

CA... Winter Weather Advisory until 11 PM PDT this evening for CAZ107.

Frost Advisory from 2 AM to 8 AM PDT Monday for CAZ110-111- 114.

NORTHWEST CALIFORNIA COASTAL WATERS... None.