textproduct: Eureka

KEY MESSAGES

-Warmer and drier conditions peak Monday -Gradual cooling and return of the marine layer are expected starting Wednesday and continuing through the week.

DISCUSSION

Most of Northern California will remain cloud free and sunny to start the work week. There are some large discrepancies in how much coastal stratus reforms through Sunday morning, but observations and HRRR guidance suggest more of a narrow band of coastal stratus caught in a southerly eddy off the North Coast.

The combination of high pressure, clear skies, and lighter onshore winds will allow for a nice warm and pleasant day for the region. Some interior valleys should break into the low 90s. Increasing low level moisture from a weak trough/front will increase the marine stratus starting Tuesday. Other than more persistent low clouds, bouts of light drizzle will also be likely late Tuesday through Thursday. The advancement of troughs and zonal flow will trend temperatures cooler. A stronger trough looks to take aim at N CA through the weekend, bringing a chance for some light rain and cooler temperatures. Ensemble members and probabilities for a wetting rainfall (over 0.1 inch) do not look promising for much rainfall at this time.

AVIATION

Winds remain much lighter with mostly VFR conditions expected. Drier air at the lower levels and a well-mixed boundary layer have prevented much coastal stratus formation. Models have been too aggressive with reformation of the stratus, but at least a narrow band may form along the north coast Monday morning. A southerly return eddy would threaten to hold stratus around Humboldt Bay and along portions of the coast through the afternoon. This is currently a low probability scenario (30%) given model trends and observations.

MARINE

Winds and seas will only slowly subside throughout the day Monday. Hazardous seas have been observed in the inner waters, and will continue in the outer waters into Monday afternoon. Winds and seas will then remain low over the northern waters through mid next week, while stronger northerlies remain in the southern waters, mainly confined around Cape Mendocino. A small, long period southerly swell will slowly build in through early next week. Northerly winds will trend stronger late in the week.

EKA WATCHES/WARNINGS/ADVISORIES

CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Hazardous Seas Warning until 3 AM PDT early this morning for PZZ450.

Small Craft Advisory until 5 AM PDT early this morning for PZZ455.

Gale Warning until 5 AM PDT early this morning for PZZ470.

Hazardous Seas Warning from 5 AM early this morning to noon PDT today for PZZ470.

Hazardous Seas Warning until 5 AM PDT early this morning for PZZ475.