textproduct: Eureka

SYNOPSIS

A weakening cold front is expected to bring a chance for light rain primarily to Del Norte and northern Humboldt counties on Thanksgiving Day. A cooling trend follows for the weekend with dry conditions and a chance for freezing temperatures during the morning hours. Additionally, a long period swell is expected to bring hazardous beach conditions late Sunday into early next week.

DISCUSSION

Nighttime Microphysics satellite imagery depicts increasing cloudiness across the area ahead of an approaching weak frontal boundary. A weakening cold front will bring light rain showers and sprinkles for Thanksgiving Day, for Del Norte and Northern Humboldt counties. Generally less a tenth is expected from early this morning into Friday. Elsewhere, mostly dry conditions are expected for Thursday and Friday.

Another shortwave trough will drop down from the NW over the weekend. Current indications are for this trough to take an over land trajectory as a ridge builds over the Gulf of Alaska. Potential for more light precip is not completely out of question just yet. General consensus is for continued dry weather Fri-Sun. Only about 20% of the cluster means are showing some light rain, while 80% suggest dry weather. Repetitive frost advisories and/or freeze warnings will most likely be forthcoming over the next several nights and early mornings as this trough reinforces the dry offshore flow over the area.

Early to mid next week, another inside slider type trough is expected. This trough may bring a greater chance for blustery north and northeast winds by mid week. Once again there is a range of possible outcomes, however the overall blocking pattern suggest predominately dry weather only with a 10-20% chance for fleeting precipitation for Del Norte and Trinity Counties. /ZVS&DUG

AVIATION...(06Z TAFS)

Conditions will transition as the approaching trough slings moisture into the area. High clouds are moving into the coast as of 6z with light rain in the forecast, expected to arrive at KCEC 10-13z. MVFR/VFR flight categories with ceilings lifting to 5000ft or so at KCEC into the late morning. It looks less likely for KACV as far as rain chances but the possibility does exist. Models have most of the areas of rain isolated to Del Norte and northern Humboldt county with around .03 or less as the total. Otherwise southerly winds will prevail for the TAF period as the cyclonic rotation arrives at the coastal terminals. KUKI will be decoupled from the active weather as most of the action is above the 40N latitude.

MARINE

Southerly winds are expected to increase to around 10 to 15 kt across the northern outer waters late tonight and into Thursday. Northerly winds are forecast to redevelop Thursday afternoon in the wake of the front, before strengthening on Friday. Models suggests the strongest winds will be south of Cape Mendocino, with potential gusts up to 25 kts. For the weekend, northerly winds are anticipated to expand northward with gusts up to around 30 kts across the outer waters by Sunday.

A forerunner mid-period WNW swell around 8 to 12 feet at 12 seconds will build in on Thursday. Wind waves around 6 to 9 feet at 8 seconds expected on Sunday. /ZVS

BEACH HAZARDS

A W-NW swell around with periods from 18-22 seconds will move through the waters Sunday evening through Monday, resulting in building surf along the beaches and increasing the potential of sneaker waves. Breaking waves will increase Sunday evening into Monday morning, reaching 14 feet by Monday morning along the northwest facing beaches. Sneaker waves are a unique hazard, with many minutes between waves. 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! /ZVS

EKA WATCHES/WARNINGS/ADVISORIES

CA... Frost Advisory from 2 AM to 9 AM PST Thursday for CAZ107- 110-112-113-115.

NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory from 3 PM Thursday to 9 AM PST Friday for PZZ450-470.

Small Craft Advisory from 11 PM Thursday to 9 AM PST Friday for PZZ455-475.