Marine Weather and Tide Forecast for Trinidad, CA

DISCUSSION
Another weak weather system riding down the east side of the ridge is expected to bring some clouds and possible some light showers in Del Norte county. Temperatures have warmed into the mid 70s to low 80s this afternoon in the inland areas while the coast lingers in the upper 50s. Breezy winds continue this afternoon along the coast with gusts around 25 mph. Stratus is expected to spread up the river valleys again tonight. Friday conditions will be fairly similar to today, although possibly a few degrees cooler. Winds will also be lighter in the afternoon.

Friday night into Saturday a slightly stronger weather system moves into the area bringing cooler temperatures and the potential for some rain or drizzle. For the Del Norte county inland areas the NBM is show a 20 to 30 percent chance of a tenth of an inch of rain. Northern Humboldt and Northern Trinity are only showing a 5 to 15 percent chance of a tenth of an inch with less than a 5 percent chance farther south. Winds are expected to increase Saturday afternoon behind this system with gusts to 35 mph along the coast and up to 40 mph in the southern inland areas. High temperatures will also be cooler for the inland areas with highs only around 70 in the warmer valleys and upper 50s along the coast. Sunday inland temperatures are expected to start warming but only a few degrees over Saturday. Saturday night is expected to be the coolest nights with some of the colder valleys potentially seeing frost if they can remain clear.

Next week high pressure is expected to build back into the area and the inland areas could see highs over 90 degrees. Currently the NBM is showing a 30 to 50 percent probability of the inland valleys exceeding 90 degrees. The models are generally showing high pressure, but there are some indications that some weak shortwaves might move over the top of the ridge bringing cooler temperatures. MKK

AVIATION
Steady northerly winds blocked by the coastal terrain will result in low cloud redevelopment this evening and overnight over Humboldt Bay and Eel delta. MVFR ceilings are highly probable for KACV with lower chances for IFR ceilings by daybreak Friday.
Sporadic MVFR or IFR cigs will also be possible at KCEC once northerlies subside and small scale eddies generate light southerly and southeasterly winds nearshore. Otherwise for UKI, VFR with occasional mid/high is expected. Now winds will remain gusty for coastal terminals early this evening with peak gusts to 25 kt or so.
There is a 50% chance for turbulence and low level wind shear for small aircraft, particularly around KACV once surface gustiness decouples this evening. Chance for turbulent flow and shallow mountain waves will continue tonight over southern Humboldt county interior (King Range) and much of western Mendocino county. DB

MARINE
Surface ridging extending from a high centered over the northeast Pacific coupled with a thermally induced trough over the California interior will continue to produce northerlies with to 25 to 30kt over the waters through tonight. Winds will ease to 10 kt or less nearshore by late evening, however. High resolution models continue to depict a couple of expansion fans in the lee of Cape Mendo and Cape Blanco this afternoon and evening. Strongest expansion fan is forecast to occur south of Cape Mendocino where gusts to 35-40 kt are highly probable based on HRRR. Gale warning remains marginal with coverage of gusts > 35kt less than 50% for marine zones 475 and 455.

Pressure gradients will start to relax north of Cape Mendo on Friday as a weak front approaches from the NW. Winds and seas are forecast to subside in response north of Cape Mendo. South of Cape Mendo, gradients will remain sufficiently tight to support gusts to 25-30 kt for a continuation of advisory conditions. Waves will also remain sufficiently steep and uncomfortable south of Cape Mendo; around 6 to 8 ft at 7 seconds.

Northerly winds and steep waves will increase again over the weekend with small craft advisory conditions likely both north and south of Cape Mendo by Sat afternoon and evening. Pressure gradients may become sufficiently steep to support gusts over 35 kt in the lee of Cape Mendo by Sunday. DB

EKA WATCHES/WARNINGS/ADVISORIES
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
Small Craft Advisory until 9 PM PDT this evening for PZZ450.

Small Craft Advisory until 3 PM PDT Friday for PZZ455.

Small Craft Advisory until 3 AM PDT Friday for PZZ470.

Small Craft Advisory until 3 PM PDT this afternoon for PZZ475.

Gale Warning until 9 PM PDT this evening for PZZ475.