textproduct: Eureka

SYNOPSIS

Gusty northerly winds will continue while generally diminishing throughout the day. Chilly temperatures could occur after the winds back off this morning and will more than likely be chilly Wednesday morning. A ridging pattern will dominate through the week with some chance of light rain this weekend.

DISCUSSION

Northerly winds will remain breezy today. A cutoff low to the south has tightened the pressure gradient against the restrengthening ridge today. Forecast soundings indicate well- mixing through the boundary layer through this period, allowing for efficient downward momentum transfer and gusty surface winds along the coast. Winds will generally ease throughout the day today, but will remain breezy through this afternoon. Winds are expected to significantly diminish tonight and into Wednesday.

Chilly, and potentially frosty, morning conditions are possible for portions of Northwest California this morning and Wednesday morning. Chances are still varied for low temperatures at or below 36 degrees this morning due to generally overcast skies and lingering elevated winds. However, the growing season has begun for Mendocino, Lake, coastal Del Norte, and the northern Humboldt coast. As a result, a Frost Advisory will be in effect this morning until 9am for a small area around Hiouchi in Del Norte County; a small area of the northern Humboldt Coast around McKinleyville, Fieldbrook and Blue Lake; areas of NE Mendocino from Piercy, Laytonville, Covelo, Willits, and Potter Valley; and a small portion of Lake County mostly around Upper Lake and Gravelly Valley Airport.

As of now, Wednesday seems like the best bet for widespread frosty conditions due to the likelihood of calmer winds and clearer skies. Due to this, a Frost Advisory could also be applicable for Wednesday morning. NBM indicates a generally high probability (85 to 95 percent) for lows at or below 40 degrees for most of Northwest California with immediate coastal regions and southern Mendocino and Lake counties having general lows in the mid to low 40s. Also on Wednesday morning, high probabilities of about 70 to 90 percent exist for temperatures at or below 36 degrees for portions of the northern Humboldt Coast from about Humboldt Hill to just north of Orick (including Eureka, Arcata, and McKinleyville). There is also about an 80 to 90 percent chance for morning low temperatures 36 degrees or less for regions of interior Del Norte, interior Humboldt, Trinity, and NE Mendocino counties.

A strong Pacific ridge will generally remain in control as additional weak fronts attempt to briefly flatten it, introducing more very slim chances for light showers, mainly in Del Norte County. Chances for a wetting rainfall (0.1 inch or higher) only reach 15% to 25% this weekend. There will be periods of rebounding high temperatures between the fronts. /JLW & JJW & EYS

AVIATION...6Z TAFs

Northerly winds eased overnight. Winds turn much lighter and northeast through Tuesday morning. MVFR CIGs from 1500 to 2500 ft AGL may linger around Humboldt into Tuesday morning, but probabilities for VFR conditions increase significantly after 10Z Tuesday. VFR conditions are then forecast to remain through this TAF period (6Z Wednesday) apart from some patchy interior valley fog. Northerly winds will increase again, with gusts up to around 20 kts at the terminals Tuesday afternoon.

MARINE

The northerly winds will continue to trend lower Tuesday while steep and some hazardous seas remain. Gale conditions will remain longer in the southern waters through late Tuesday night. Steep and hazardous seas of 13 to 15 ft can be expected in the southern waters into Wednesday morning. A northwest swell reaching 9 ft at 13 seconds will add to the combined sea height. The northerly winds will more significantly drop Wednesday afternoon, but the southern waters around and downwind of Cape Mendocino will remain a focus of increased northerly winds. Localized gale strength wind gusts may be found lee of the cape late in the week or into the weekend.

EKA WATCHES/WARNINGS/ADVISORIES

CA... Frost Advisory until 9 AM PDT this morning for CAZ101-103- 109>115.

NORTHWEST CALIFORNIA COASTAL WATERS... Gale Warning until 4 AM PDT early this morning for PZZ450- 470.

Gale Warning until 10 AM PDT this morning for PZZ455.

Gale Warning until 3 AM PDT Wednesday for PZZ475.