Marine Weather and Tide Forecast for Ferndale, CA

KEY POINTS:

- Rain begins late Wednesday and continues through Thursday.

- Strong winds Wednesday into very early Thursday. Peak winds very late Wednesday (gusts 30 to 50 mph with locally higher gusts at wind prone ridges and coastal headlands).

- Lowering snow levels Thursday (around 4000 ft.) mostly affecting the highest mountain passes.

- Potential for thunderstorms through the day Thursday with a chance for small hail.


DISCUSSION
High pressure will persist over Northwest California Tuesday, bringing very similar conditions to the last several days. Low clouds and fog will continue for Tuesday morning, although the coverage is a bit more limited. Some valleys in southern Mendocino and southern Lake counties are expected to remain clear. Afternoon highs continue to be in the 60s to low 70s and again have kept them below the NBM for Tuesday.

Early Wednesday, the next weather system will begin to approach the area. Increasing southerly winds are forecast to start by early Wednesday morning, first on the ridges and then to lower elevations along the coast. These winds are expected to peak late Wednesday evening. 925 mb winds of 70 kt just off the coast are depicted in several models. There is support for this in the ensemble clusters, but still some variability between clusters. The ECMWF EFI is also highlighting the significant winds, but showing a shift of tails near 1 indicating potential variability on the outcome. Currently it looks like most areas will see wind gusts of 30 to 50 mph with the higher winds over the higher terrain and along the coast. Currently it looks like a wind advisory may be needed for portions of Del Norte, Humboldt, Mendocino and Lake counties.

Rain is forecast to start by early Wednesday afternoon on the south slopes and along the Mendocino coast. Farther north, the onset of rain is forecast to occur a bit later, especially north of Cape Mendocino. The Humboldt Bay area may be delayed even more, possibly until late evening, due to the downsloping from the King Range. Most areas are expected to see 1 to 2 inches of rain with local amounts upwards of three inches Wednesday night through early Thursday morning. Some flooding is possible in small streams, urban areas and poor drainage areas.

Thursday morning there may be a brief break in the rain behind the front, but showers are expected to take over fairly quickly as the upper level trough moves over the area. This trough is bringing some of the coldest air so far this fall. Snow levels are expected to fall as low as 3500 or 4000 feet by Thursday evening. Most of the main highway passes are not expected to be impacted, but Hwy 3 at Scott Mountain summit has a 30 percent chance of seeing over 3 inches of snow.

The colder air is forecast to generate some instability, resulting in a potential for thunderstorms through the day on Thursday. Some of these storms may also contain small hail. Generally it is not expected to be cold enough to cause widespread problems, but there could be some accumulations.

Friday, the upper level trough starts to move out of the area and high pressure quickly starts building back in. There isn't very good model agreement on this yet, but some models show some precip developing for the coastal counties. Saturday is generally looking drier, especially in the afternoon. Inland valleys may see chilly temperatures, but fog is likely which may keep the valleys from dropping below freezing. Another system is expected to bring additional rain to the area Sunday, although this looks weaker than the earlier system. MKK



AVIATION
(6Z TAFs)...Stratus and fog have returned to the coastal terminals. LIFR conditions with low visibilities are being observed and are likely to continue through the night. Model guidance shows high probabilities for ceilings to lift and scatter by 18Z Tuesday, but there is a 30% chance for at least IFR ceilings to persist through the day. Regardless, confidence is high on the return of stratus Tuesday evening, but the marine layer is likely to deepen, bringing MVFR to IFR impacts. Outside some of the river valleys, most inland areas are forecast to remain VFR for the next 24 hours.
There is potential for UKI to receive stratus Tuesday night into early Wednesday. JB



MARINE
A brief period of mild conditions are expected Tuesday as north winds weaken and a mid-period swell and residual steep wind waves begin to decay. An approaching system will turn winds southerly starting Wednesday morning. These will gradually build Wednesday and peak Wednesday night. Gale force winds are likely and isolated storm force gusts are possible. In addition to hazardous winds, steep wind waves over 10 ft are expected Wednesday night through Thursday.

Winds ease behind the front and turn southwesterly. As the surface low moves to the north of the area, south winds may briefly pulse upward again Thursday, with lower (30%) chances for gale force gusts if the low moves southward. Otherwise, gusts of 25-30 kts are possible, especially in the northern waters. Seas will remain elevated as steep wind waves combine with a large long-period NW swell of 13-15 ft filling in Thursday and Friday. There is growing confidence on another storm arriving late this coming weekend into early next week.



EKA WATCHES/WARNINGS/ADVISORIES
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
Gale Watch from Wednesday afternoon through late Wednesday night for PZZ415-450.

Gale Watch from Wednesday afternoon through late Wednesday night for PZZ455.

Gale Watch from Wednesday morning through late Wednesday night for PZZ470.

Small Craft Advisory until 10 AM PST this morning for PZZ475.

Gale Watch from Wednesday morning through late Wednesday night for PZZ475.