textproduct: Eureka

KEY MESSAGES

* Cooler temperatures will arrive this weekend, bringing chances for isolated interior frost.

* The extended forecast is dry

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

SYNOPSIS

A colder airmass will bring chances for isolated frost over the coming mornings. The extended forecast does not currently have chances for additional rainfall.

DISCUSSION

A colder air mass will continue to affect Northwest California this weekend. This will bring the potential for isolated frost for some of the coldest interior valleys (particularly Hayfork). Early this morning, the combination of offshore winds and increasing mid to high level clouds from a nearing frontal boundary should limit the frost potential. Wind sheltered interior areas that recorded rainfall may also likely see radiational fog early this morning, but the increasing higher clouds should limit coverage. A trough will pass through Sunday to reinforce some chillier air and continue an isolated interior frost threat. Chances for chilly temperatures and frost will continue into at least early next week. The passing trough Sunday and a frontal boundary preceding it Saturday 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

The well mixed environment with light offshore winds early this morning could aid in inhibiting the expected overnight radiational fog development. Wind sheltered areas may see some fog still, including ACV. Mid to high levels clouds arriving may also limit the fog coverage. Any low clouds that may develop are anticipated to scatter or clear mid to late morning.

MARINE

Northerly winds are quickly strengthening. The northerly winds will reach gale strength by early this morning in the southern waters. Steep short periods will build with the wind, entering the inner waters at times. The northerlies will weaken some Sunday with a passing trough, but will restrengthen early next week. A small long period WNW swell is forecast to arrive Monday, at around 3 to 6 ft at 16 to 17 seconds.

FIRE WEATHER

A pronounced offshore wind surge will continue early this morning, drying out the interior somewhat today with min RH dropping to the low 20s to upper teens. The extended forecast does not include any more chances for wetting rain.

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 Sunday. 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 there recently. Stay safe and never turn your back on the ocean!

EKA WATCHES/WARNINGS/ADVISORIES

CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 11 PM PDT this evening for PZZ450.

Small Craft Advisory until 9 AM PDT this morning for PZZ455.

Small Craft Advisory until 7 AM PDT Sunday for PZZ470.

Gale Warning until 11 AM PDT this morning for PZZ475.