textproduct: Eureka

SYNOPSIS

Widespread rainfall has arrived to the area and will turn showery this evening and overnight. Small hail and isolated thunderstorms are possible at the coast this evening and overnight. Light snow is possible down to 2500 ft overnight. Near freezing to freezing temperatures possible Friday morning. Warmer temperatures likely this weekend.

DISCUSSION

The cold front has arrived to the area bringing widespread rain and gusty winds. Gusty south winds will turn westerly this afternoon, and are likely to remain breezy (gusts of 20 to 30 mph) through the evening. Lake County could see westerly gusts of up to 35 mph this afternoon and evening. Isolated higher gusts up to 45 mph are possible in the higher elevations.

Rainfall totals remain steady, with total amounts of just under 1.00" to 2.00" for the lower elevations of Del Norte, Humboldt, and northern Mendocino. The higher elevations could see as much as 4". Eastern Trinity, Southern Mendocino, and Southern Lake will see much less precip, struggling to even reach a quarter to a half inch. Snow levels are being observed at around 5000 feet early this afternoon. These levels will sharply fall behind the frontal passage, perhaps as low as 2500 ft. This could bring some light snow accumulations to the highest passes on Highways 199, 299, and 36. Any snowfall will likely be slushy and may not stick to the roads, however this will need to be watched as increased shower activity could bring greater accumulations. At Scott Mountain Pass on Highway 3, 3-6" of total snowfall is expected. A Winter Weather Advisory has been issued for the Trinity Horn for this snow, and the likelihood of freezing temperatures and hazardous road conditions through Thursday morning.

At the coast, showers with isolated thunderstorms and small hail are possible tonight, primarily for Del Norte and Humboldt Counties, into early Thursday morning. Temperatures in the 40s and warmer road temperatures will likely keep accumulations brief and minor, but this can still produce very slick road conditions. Be cautious driving tonight in these areas.

Showers taper off Thursday and skies begin to clear. Temperatures are likely to be chilly Thursday and Thursday night. High temperatures are likely to be in the 50s for much of the interior and the coast. Low temperatures are likely to drop into the 30s or low 40s across the area. The big question is if valley fog will develop. With such a cold, dry airmass, and clearing skies, widespread frost and near-freezing temperatures are possible. Fog from recent rains could complicate this and keep temperatures higher, however.

Regardless, temperatures will rebound this weekend with high 70s to mid 80s likely for the interior by Saturday. Coastal temperatures could approach the 70s, especially a few miles inland. Model guidance suggests the potential for more light rain showers and possibly interior thunderstorms mid next week. JB

AVIATION

A cold front sweeping through Wednesday is brining a sharp westerly wind shift and moderate to locally heavy rainfall. Mostly MVFR CIGs will continue, with TEMPO movement into IFR, mainly with the higher precipitation rates. Winds will remain gusty from west overnight as CIGs and VIS improve with a turn to a more showery precipitation mode. VFR conditions will then take hold going into Thursday morning while winds turn lighter.

MARINE

A sharp westerly shift occurred Wednesday afternoon behind a passing cold front. A very steep and hazardous post-frontal westerly swell will quickly push in Wednesday night, peaking late Thursday morning at 11 to 15 feet. Historically, these types of setups have brought a surge in wave height larger than modeled. A Fresh Breeze of 15-20 kts westerly winds will continue into Thursday morning before quickly weakening as the direction turns more northerly. Northerly winds then strengthen from the south to north Thursday evening. The northerlies increase more Friday, and localized gales are forecast south of Cape Mendocino Friday afternoon through Friday evening. Calmer conditions are forecast to begin by late Saturday.

EKA WATCHES/WARNINGS/ADVISORIES

CA... Wind Advisory until 3 PM PDT this afternoon for CAZ101-102.

Winter Weather Advisory until 11 AM PDT Thursday for CAZ107.

NORTHWEST CALIFORNIA COASTAL WATERS... Gale Warning until 3 PM PDT this afternoon for PZZ450.

Small Craft Advisory until 5 AM PDT Thursday for PZZ450.

Hazardous Seas Warning from 5 AM to 5 PM PDT Thursday for PZZ450.

Small Craft Advisory until 1 PM PDT Friday for PZZ455-475.

Small Craft Advisory until 11 PM PDT this evening for PZZ470.

Hazardous Seas Warning from 11 PM this evening to 5 PM PDT Thursday for PZZ470.