textproduct: Eureka

KEY MESSAGES

- Gradual cooling trend and deepening marine layer this week and continuing into the weekend.

- Enhanced west-northwest winds through the channeled terrain and higher ridges on Wednesday, then shifting to the coast on Thursday.

- Another weak cold front has the potential to bring breezy to gusty winds Friday and into the weekend.

DISCUSSION

A gradual cooling trend will start on Wednesday as a cold front moves through. Enhanced west-northwest winds are expected along the channeled terrain and exposed ridges in the wake of a passing weak front.

Gusts from 25 to 35 mph are most likely, with locally up to around 40 mph possible. Mendocino and Lake counties will see better coverage of stronger winds, where there is a high probability (60 to 80%) for gusts over 30 mph Wednesday afternoon and evening. The combination of dry weather, warm temperatures, and gusty winds will bring a locally elevated fire weather threat for portions of Lake County (see Fire Weather section). Other than more coastal low clouds, bouts of patchy drizzle will also be possible Wednesday night.

Thursday, a surface high pressure will build in. This will aid in rebounding daytime temperatures across the area on Thursday. In addition, breezy north- northwest gusts of 25 to 35 mph is expected over the coastal and exposed ridges. Locally strongest winds are possible over the exposed ridges in the King Range. Expect low clouds mixing and clearing out Thursday afternoon, allowing a mostly sunny day, with more stratus redeveloping overnight around Humboldt Bay and vicinity.

A stronger upper-level trough will drive southward Friday and through the weekend, promoting seasonal temperatures. Additional breezy to gusty winds are also expected with the pressure gradient tightening across the area. Dry weather is expected to remain under prevailing dry weather through this weekend. /ZVS

AVIATION

LIFR conditions were underway early Tuesday morning, along with some fog. A weak front is passing and will present opportunity for light drizzle. The front and approaching trough will deepen the marine layer to trend ceilings higher and give better opportunity for MVFR to perhaps VFR levels through the afternoon if scattering is fully achieved. Northerly winds will increase through the afternoon behind the front, and gusts of 20 to 25 kts are forecast for the terminals before winds ease into the evening.

MARINE

After a brief lull, northerly winds will quickly increase across the waters Wednesday behind a front. Advisory level wind gusts of 20-30kts will occur through the afternoon. The southern waters will see further strengthening overnight. The Gale Watch has been upgraded to Gale Warning for the southern outer zone (475). A Gale Watch has also been hoisted for the southern inner zone (455) for Thursday when stronger winds are expected to work closer to the coast. The seas state will turn steep from short period seas, and this will be the dominant wave group other than a small long period southerly swell.

FIRE WEATHER

Enhanced west- northwest winds are expected along the channeled terrain and exposed ridges on Wednesday, with gusts of 20 to 35 mph likely. Locally higher gusts are possible south in Lake County. Onshore marine moisture will continue to promote moderate to good RH recoveries for areas below the inversion (<2000 feet). Daytime RH recoveries will be generally in the upper 20s and 30s percent on Wednesday, with a slight lower percent each day through Friday. Locally elevated fire weather conditions are expected on zones 419 and 421 on Wednesday due to low daytime RH combine with locally gusty winds over the ridges. A deeper trough will likely bring stronger winds Friday and into the weekend. /ZVS

EKA WATCHES/WARNINGS/ADVISORIES

CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory from 5 PM Wednesday to noon PDT Thursday for PZZ455.

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

Small Craft Advisory from 11 PM Wednesday to 6 AM PDT Friday for PZZ470.

Small Craft Advisory from 5 PM Wednesday to 2 AM PDT Thursday for PZZ475.

Gale Warning from 2 AM Thursday to 6 AM PDT Friday for PZZ475.