textproduct: Eureka

AVIATION...12Z UPDATE

Coastal areas can expect LIFR through the morning before afternoon clearing takes effect. Northerly winds are to be expected for CEC and ACV. An incoming cold front will disrupt the marine layer, decreasing the chances for LIFR developing Friday night. IFR to MVFR is more likely at this point. Inland areas can expect NW winds up to 10kts with afternoon gusts up to 15kts possible and VFR conditions. Winds could be erratic near terrain as well, possibly causing Low Level Turbulence near terminals. DS

PREV DISCUSSION

/issued 1231 AM PDT Fri Oct 9 2026/

KEY MESSAGES...

* A developing trough will bring much cooler conditions by Friday and the weekend.

* Strong, gusty north wind close to shore and along ridges this weekend.

* No wetting rain forecast for the next 10 days.

SYNOPSIS...Much more seasonable, cooler and moister conditions arrive begin to arrive today with fog slowly maxing out along shore. Strong north winds will impact the area through the weekend. Chances for wetting rain remain near 0.

DISCUSSION...High pressure is finally beginning to break down across the area, spelling the end of 6 days straight of much above normal temperatures and shallow marine fog along shore. Through the day today, weak low pressure moving over the eastern Pacific will weaken heat and bring generally much more seasonable conditions. Highs will drop back into the lower 90s with a deepening though still present marine layer along shore. A broad trough and associated surface cold front will further cool conditions by Saturday and into Sunday. High temperatures will drop back into the 70s. Despite the front, few models show any moisture with front. Some very light coastal drizzle is possible as the marine layer lifts, but chances of wetting rain are below 10%. SOme high resolution models show showers forming along the Sacramento Valley around Sunday, an offshoot of much broader convection in Southern California. That said, general lacking precipitable waters and little to no instability make virga and weak radar returns the most likely outcome.

As the trough dips south, there is strong model agreement that there is potential for unusually (EFI values of 0.85) strong north winds Saturday and Sunday. Winds may be particularly enhanced by low pressure detaching from the trough and moving south, though actually instability with this low is tenuous at best. NBM shows most likely wind gusts along shore of 35 mph on Saturday. The strongest winds would be on coastal ridges and headlands during the day Saturday. There is a 80% chance of gusts over 45 mph over the King Range and in the coastal waters, though that chance is only 10 to 20% for more populated areas like Crescent City and Humboldt Bay. Winds will most likely keep marine air scattered out along the coast, especially as winds turns slightly easterly by Sunday morning and into early next week.

As winds weaken, clear skies and dry air may allow for freezing conditions in the morning by Monday (20% chance for eastern interior valleys). Even the coast has good chances of lows int he low 40s, the coldest of the year so far. Ensembles remain dry throughout the extended forecast period (next 10-14 days), though much weaker high pressure will generally result in more seasonable temperatures. /JHW

AVIATION...06z TAF...A very shallow marine layer is again impacting the coast, bringing a thin band of LIFR fog and ceilings to near coastal terminals. LIFR conditions will most likely persist overnight. Weakening high pressure and increasing winds will finally aid in better and deeper clearing by Friday afternoon. High resolution models suggest winds will help keep more VFR conditions through Friday evening, though more sheltered areas such as Humboldt Bay may see LIFR fog and ceilings return one more time (40% chance), though slightly lifted IFR ceilings are more likely. /JHW

MARINE...North winds will quickly increase Friday and push closer to shore as low pressure pushes east of the area. Gusts will most likely be near gale conditions by this afternoon in the outer waters. Of course, steep short period seas up to 10 feet will rise in response. Winds will continue to strengthen Saturday as a broad trough dips north of the area. By Saturday, there as 80% chance of gusts over 45 kts in the southern outer waters with gale conditions pushing in the inner waters. Very windy conditions will then persist until at least next Monday. Around Sunday a long period swell around 5 feet at 22 seconds will augment the sea state. If short period seas were not so steep, such a swell would create a significant sneaker wave risk. /JHW

FIRE WEATHER...Prolonged much hotter and drier than normal conditions will finally begin to ease today. However due to the lagging nature of heavier fuels, ERC values will crest near the 90th percentile on Friday and Saturday. Such values will most likely be record breaking for October. At the same time, strong north winds gusting 30 to 40 mph will build near shore and along exposed ridges Saturday. Passing low pressure may aid in more moderate winds mixing into usually protected valleys Saturday afternoon. Winds will turn more easterly by early Sunday, helping to further dry conditions and produce poor RH recovery at high elevations. Although by Saturday, conditions will be much more seasonably cool and moist (highs in 70s and RH around 30 percent), the lack of any rain chances and recent drying will still support near record breaking Burning Index values for October around Saturday. All that said, there is potential for much above average fire activity through the weekend. /JHW

BEACH HAZARDS...Strong winds will generate very steep short period seas through the weekend with breaking waves running up over 16 feet at area beaches by Saturday evening. Conditions will be most hazardous on northwest facing beaches. Even as short period seas continue, a very long period swell building in early Sunday around 4 feet at 24 seconds will create an increase in the sneaker wave risk. Though short period seas will dimish this risk somewhat, some infrequent, but much higher wavers should be expected Sunday. Beach hazards will also be enhanced by tidal anomaly of 2 feet. Take extra care on area beaches. Updates to come when available. /JHW

EKA WATCHES/WARNINGS/ADVISORIES

CA... Dense Fog Advisory until 8 AM PDT this morning for CAZ101- 103.

NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until midnight PDT tonight for PZZ450.

Gale Warning from midnight tonight to 9 PM PDT Saturday for PZZ450.

Small Craft Advisory until 3 PM PDT this afternoon for PZZ455.

Gale Warning from 3 PM this afternoon to 9 PM PDT Saturday for PZZ455.

Hazardous Seas Warning until 9 PM PDT this evening for PZZ470.

Gale Warning from 9 PM this evening to 9 PM PDT Saturday for PZZ470.

Small Craft Advisory until 9 AM PDT this morning for PZZ475.

Gale Warning from 9 AM this morning to 9 AM PDT Sunday for PZZ475.