Marine Weather and Tide Forecast for Big Lagoon, CA

FXUS66 KEKA 080711 AFDEKA

AREA FORECAST DISCUSSION National Weather Service Eureka CA 1211 AM PDT Fri May 8 2026

SYNOPSIS...Temperatures will slowly warm for the interior into the weekend. A shallowing marine layer may allow for some break in gloomy clouds close to the coast into the weekend.

KEY MESSAGES...

-High pressure building into the weekend will warm interior temperatures. High temperatures will peak Sunday and Monday with minor to moderate heat risk for interior valleys in Mendocino, Lake, and Trinity Counties.

-Gloomy coastal skies more likely to scatter and clear alongshore in the afternoons this weekend with some enhanced afternoon northerlies around Sunday.

-Cooler temperatures and slight thunderstorm potential late next week.

DISCUSSION...Very weak ridging will arch over the area into the weekend. This will bring slightly warmer and drier conditions to the interior. Interior highs will be slightly above normal in the mid 80s by Saturday. Building heat will help shallow the marine layer along the coast. This will both increase the potential for night time fog but also increase the potential for some coastal blue skies in the afternoon. Friday appears to be the best chance to see blue on the coast with a 60% chance of skies at least scattering out in the afternoon. Stratus looks to slightly resurge on Saturday. North wind will increase along shore Saturday afternoon but especially Sunday. Despite a stronger marine inversion, the wind may help mix out some clouds on Sunday.

High pressure will continue to build Sunday and into early next week. High temperatures will most likely peak around Next Monday.
Interior highs will most likely reach the low to mid 90s. Solidly above average temperatures will promote generally minor to moderate Heat Risk with the greatest risk in Lake County due to warm conditions continuing overnight. A very shallow marine layer along shore will likely make for more scattered skies in the afternoon.
Should skies clear enough, coastal temperatures could reach near 60.

Most model ensemble members show a cutoff low forming up along shore mid to late next week. This low will help slightly weaken high pressure and drop interior temperatures. This low could bring a threat of thunderstorms, but most models show it staying too dry and too far offshore to bring much risk. Most thunderstorm potential late next week is now more than 10% at the moment in most models.
/JHW

AVIATION...A weak front is pushing through N CA Friday. The marine layer deepened in response, bringing wider coverage of IFR to MVFR ceilings and light coastal drizzle. HRRR shows high probabilities for the stratus to clear out Friday afternoon with increasing dry, northerly flow. Around Humboldt Bay to ACV may see longer coverage of MVFR ceilings with moisture pooling from lighter NW winds. Probabilities of MVFR ceiling drop to 30% after 21Z for ACV and 10% at CEC after 20Z. Stratus is forecast to invade the UKI valley again from the south again, taking ceilings below 1700 ft AGL. Improvement at this terminal should occur quicker, through 16-17Z. Northerly winds increase in the afternoon, with 15-25 kt gusts likely at the terminals.

MARINE...Southerly winds starts to increase to fresh to strong breezes by Friday afternoon. Saturday these stronger winds are expected to begin to expand farther north with 15 to 20 kt across much of the area north of Cape Mendocino. This is expected to build the short period wind driven waves to around 4 to 7 feet.
Stronger winds are expected on Sunday with near gale to gale force gusts possible by Sunday afternoon. Winds are anticipated to gradually ease early next week; however, steep seas will prevail across the coastal waters. MKK
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