textproduct: Eureka

KEY MESSAGES

* Cooler temperatures continue into the early work week, bringing chances for isolated interior frost.

* Slight chance for showers and thunderstorms this afternoon and evening.

* The extended forecast is dry.

* A long period swell will bring a moderate risk for sneaker waves early this week.

SYNOPSIS

A colder airmass will bring slight chances for isolated frost over the coming mornings. Dry weather is likely for the next week.

DISCUSSION

A large trough is forecast to move over Northern California today. High clouds along with chances for rain for isolated areas are likely. Chances for showers are low, but models indicate a chance for them along the border of western Siskiyou and possibly around the Yolla Bollys. There may be a light wetting rain, if any.

Wind sheltered interior areas that recorded rainfall Thursday night into early Friday morning may see radiational fog, but this will be less likely into the coming week, especially with cloud cover sweeping in ahead of the frontal boundary. As previously mentioned, a trough will pass through today which will reinforce some chillier air and continue an isolated interior frost threat. Chances for chilly temperatures and frost will continue into at least early this coming week. The passing trough today and the frontal boundary preceding it will be dry, but could bring a weak afternoon shower or two. The extended outlook looks to remain dry with no chance for measurable rainfall.

AVIATION...(18Z TAFs)

High clouds have made their way eastward after the passing of the frontal boundary, minus a few convective cumulus clouds which are progressing east as well. Mostly low cloud cover in the form stratus is anticipated overnight into Monday morning for the coastal terminals as post frontal clearing helps flight categories for the rest of Sunday during daylight hours. Slightly gusty southerly winds are also anticipated from about Humboldt Bay up to Point St George. The southerly reversal flow could bring any low cloud development along the Humboldt Coast up to the Del Norte Coast. KUKI has a VFR prevailing forecast but the ASOS is not functioning and so you may see "AMD NOT SKED" until further notice.

MARINE

Winds have eased slightly over the coastal waters and will continue to back away from the shoreline north of Cape Mendocino. Northerlies are anticipated to build this afternoon with Gale force gusts in a few localized areas to the south of Cape Mendocino. Steep short periods will build with the wind, entering the inner waters at times. A small long period WNW swell is forecast to arrive Monday, at around 3 to 6 ft at 16 to 17 seconds. The Gale Watch covering Monday afternoon 22z to Tuesday afternoon 22z, has been upgraded to a Gale Warning for gusts up to 40 kts in the southern outer waters and hazardous mixed sea state.

BEACH HAZARDS

A long period west northwest swell at 3 to 6 ft with a period up to 17 seconds will build in Monday. This swell will bring a moderate risk for sneaker waves. A smaller 3 ft long period south swell will also bring some risk for sneaker waves for south facing beaches starting today. High astronomical tides will increase the danger, especially over rocks and jetties.

Sneaker waves are a unique hazard, with up to 30 minutes between waves. Large, unexpected waves can sweep across the beach without warning, sweeping people into the sea from rocks, jetties, and beaches. These sneaker waves can also move large objects such as logs, crushing anyone caught underneath. Even ankle to knee deep water can knock you down and drag you out when a sneaker wave hits. Pay attention and stay above the high water line and any wet sand to stay safe. If the ground is wet, waves have surged.

EKA WATCHES/WARNINGS/ADVISORIES

CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory from 9 PM this evening to 3 AM PDT Tuesday for PZZ450.

Small Craft Advisory until 9 AM PDT Tuesday for PZZ455.

Small Craft Advisory until 3 AM PDT Tuesday for PZZ470.

Small Craft Advisory until 3 PM PDT Monday for PZZ475.

Gale Warning from 3 PM Monday to 3 PM PDT Tuesday for PZZ475.