Marine Weather and Tide Forecast for Eureka, CA

DISCUSSION
A Pacific system and associated frontal system is swinging northeastward toward Central California this afternoon, while moisture surge northward across the area. This will bring light to moderate rainfall late this afternoon into evening, focusing especially across Mendocino and Lake counties. This will be followed by showers moving north-northwest across most of the area this evening through Wednesday morning. Expect showers to gradually tapper off from north to south throughout the day on Wednesday. Total rainfall amounts are forecast to be from 0.5 to 1.0 for Lake and the eastern portion of Mendocino and eastern Trinity counties, with the highest amount expected in Lake.
Locally up to 2.0 inches are expected over the higher terrain in Lake County. Mendocino Coast, interior Humboldt, Del Norte, and western Trinity are likely to see less than a half inch across the area, with much of Humboldt and Del Norte unlikely to see even a tenth of an inch.

While this is primarily a rain event for lower elevation, snow levels will hover around 5500 to 6000 feet, which could bring light snow to high mountain passes like Scott Mountain Pass on Highway 3.

In addition, increasing east to southeast are expected tonight through Wednesday afternoon over the interior, mainly focused over Mendocino and Lake counties. Gusts from 25 to 35 mph are expected over the exposed ridges in Mendocino and Lake counties.
However, with the easterly winds may aid in funneling gusty winds in Lake County. The National Blend of Models (NBM) 90-95th percentile (high end) indicates gusts around 30 mph in the lower elevations of Lake County late tonight through early Wednesday afternoon.

Dry weather is expected for late of the work week as a weak high pressure build into the area. Expect seasonably daytime temperatures, and chilly overnight low temperatures with freezing minimums highly probable for valleys in Trinity. Most of the coastal areas will remain with stratus along periods of night and morning fog through Friday.

Unsettled weather pattern returns this weekend and into early next week as a much deeper, positively tilted cut-off trough will slowly approach shore with a broad surface low over the Pacific.
Ensembles models, and WPC Cluster Analysis are in a good agreement with the low moving near the California Coast over the weekend, bringing high chance of widespread precipitation. High uncertainty remains regarding the specific details at this moment.

Heading through early next week, a potent cold upper trough with 500 mb temperatures from -32 to -38C will dig south-southeastward from the Gulf of Alaska into the West Coast. The most recent operational models are suggesting temperature aloft of -4C at 850 mb, -15C at 700 mb, and -35C at 500 mb over NW California. The cold airmass will aid in the development of steep lapse rates promoting heavy precipitation along with isolated thunderstorms and accumulating small hail along the coast early early next week.

Mountain snow is the number one of concerns with these systems.
Heavy snow, with storm total accumulations at or above 1-2.5 feet across the higher ridges, will be probable from Saturday morning through early next week. Snow levels are expected to starting around 5,000 feet Saturday, and continue to gradually dropping to around 1,500 to 3,000 feet MSL by early next week as the upper level trough passes overhead and brings cold air aloft. However, uncertainty exist with snow levels due to it could be lower during convective showers. Travel impacts are expected from Saturday through mid next week. Stay tunes! /ZVS

AVIATION
VFR conditions persist through the early afternoon today inland. Broken high level clouds have filled in and will lower through the day from the south to north reaching between 5 and 10 kft by early this evening. Rain showers will build in the southern half of the area and around KUKI this afternoon and evening, bringing mostly MVFR with possible periods of IFR ceilings mostly from around 22Z-04Z down in Mendocino and Lake counties. The North Coast will stay drier but have a 30% chance of MVFR ceilings late tonight with elevated overcast ceilings.



MARINE
Moderate north winds have now pushed far into the outer waters yet some short period seas remain near 6 feet close to shore.
Short period seas will gradually fall below 6 feet through the afternoon. In addition, a steep, mid period westerly swell will fall below 7 feet, allowing combined seas to subside below 10 feet in all but the furthest out waters.

Relatively calm winds and seas will persist until around late Thursday night into Friday. At that time moderate to strong north winds will return to the southern waters. At the same time a steep long period northwest swell will build, peaking up to around 14 feet Friday at 16 seconds. This swell will, on its own, produce sea hazardous for small craft. Seas will then remain elevated into the weekend as another winter storm passes over the area.



BEACH HAZARDS
Generally mild beach conditions expected through Thursday. Then a steep, northwest long period swell will build in Thursday evening and peak around 13 feet at 16 seconds on Friday.
This swell will align with beaches in Humboldt and Del Norte counties and may produce rapid and unexpected beach run up of over 18 feet. Calmer winds and few short period seas along the North Coast Friday will further enhance set behavior and make waves more sneaky, especially on steep beaches. Take care if going to the beach late in the week. Stay off of rocks, logs, and jetties and never turn your back to the ocean! JHW/DS



EKA WATCHES/WARNINGS/ADVISORIES
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
Small Craft Advisory until 4 AM PST Wednesday for PZZ470.

Small Craft Advisory until 4 PM PST this afternoon for PZZ475.