textproduct: Eureka

KEY MESSAGES

* A general troughing pattern will bring additional light rain over the region today and periods of unsettled weather over the weekend.

* Overnight temperatures for the interior will turn chilly, bringing chances for frost this morning and through the weekend.

SYNOPSIS

Early this morning, temperatures for the interior will turn chilly, bringing chances for frost this morning and through the weekend. A general troughing pattern will bring additional light rain chances today and periods of unsettled weather over the weekend.

DISCUSSION

A second colder and somewhat unstable area of low pressure will continue to move by the area. This will continue the chances for showers and perhaps a couple of coastal thunderstorms.

As the environment attempts to clear out through this morning, much cooler overnight lows will develop for the interior. If clouds do clear out and fog does not develop, areas of frost will be likely for the interior. There is still some question on the amount of clearing or even additional light showers, especially with the numerous troughs forecast through the weekend. These will also bring a shot for some isolated thunderstorms. Despite the uncertainty, a Frost Advisory has been issued for southern Trinity, northeastern Mendocino, and northern Lake counties due to the forecast lows being in the mid 30s and the fact these cold temperatures are occurring so early in meteorological fall.

The broad upper low to the north will stall ahead of blocked flow through the weekend, with weaker shortwave disturbances rotating in. More weak troughing may redevelop behind it. This gives mixed signals for the extended outlook. There looks to be some sort of warmup early to mid next week, but if it occurs, it should be short lived if the troughs continue moving through. There are also questions about whether tropical moisture may stream northeast toward the region from decaying tropical systems well off the coast. Model guidance has a large variance in possibilities ranging from completely dry after Sunday to several chances of showers and possibly thunderstorms mid to late week.

AVIATION...(06Z TAFs)

Generally unsettled weather continues with isolated showers or drizzle moving through this morning, especially through Del Norte County and northern Humboldt. Ceilings are expected to lower to MVFR to IFR by this morning with some lifting into the afternoon for coastal terminals. Skies will continue to clear for interior regions of Northwest California through the next 24 hours. Ceilings will drop again for coastal terminals later this evening.

MARINE

A trough from the north is bringing steep NW swell at 8 to 11 ft at 11 seconds to much of the waters. With buoys reporting over 10 feet a Small Craft Advisory has been issued for waters north of Cape Mendocino through this morning. Otherwise winds will be light for most of the waters through Saturday. Then, northerlies will strengthen some through the weekend, mainly over the southern waters south of Cape Mendocino. The northerlies do not look to fully strengthen again until early next week. Hurricane Marie will deliver a long period southerly swell Saturday. Though small, at around 4 ft at 16 seconds, is a larger than typical swell from this direction.

BEACH HAZARDS

Hurricane Marie will usher in a long period southerly swell of 3-4 feet at 16 seconds for south facing beaches by Saturday into Sunday. Thus, there could be a risk of sneaker waves, especially if the swell comes in slightly larger.

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... Beach Hazards Statement from late tonight through Monday evening for CAZ104-109.

Frost Advisory until 9 AM PDT this morning for CAZ108-110- 111-114.

NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 9 AM PDT this morning for PZZ450- 470.