textproduct: Eureka

KEY MESSAGES

- Above-normal temperatures through Tuesday, with interior Minor HeatRisk.

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

- Enhanced west-northwest winds through the channeled terrain and higher ridges on Wednesday, followed by breezy north-northwest winds along the coast and exposed ridges on Thursday.

-Stronger winds possible Friday and into the weekend.

DISCUSSION

Coastal stratus with some fog is forecast to form and persist Tuesday. A local wind eddy will dictate how fast the clouds can dissipate, and there is a chance it lingers at least into the afternoon. A weak trough and front will move through late Tuesday through Wednesday. Light drizzle and perhaps a few light showers will be all the precipitation received from them.

Behind the passage of the trough, a Northeast Pacific trough and a ridge of high pressure to its south will begin strengthening the pressure gradient late Wednesday, with further strengthening Thursday. Northerly to westerly winds increase in response, with breezy conditions, particularly inland over the ridges and through channeled terrain. 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 overnight. These winds will remain Thursday, but will be weaker. A stronger Northeast Pacific trough will drive into the Pacific Northwest Friday, and this will create an even tighter pressure gradient and likely stronger winds Friday and into the weekend.

AVIATION

Stratus expected to fill in along the north coast through Tuesday morning. Uncertainty still exists on how shallow the ceilings will lower to. The neighboring profilers are showing a shallow marine layer, and guidance has trending with higher probabilities for LIFR conditions and possibly some fog. Southerly return flow from a wind eddy has established itself along the Humboldt and Del Norte coast. This feature will hold the stratus over the immediate coast Tuesday until it weakens, which will likely occur later in the afternoon after 20Z. Surface winds will be light, with some west to northwest gusts in the afternoon through the interior.

MARINE

The local pressure gradient is being weakened by an approaching weak front and trough. As a result, northerly winds will continue trending low through Tuesday. Winds will remain stronger, up to 20 kts in the southern waters, mainly south of Cape Mendocino. Behind the passage of the trough, a Northeast Pacific trough and a ridge of high pressure to its south will begin strengthening the pressure gradient late Wednesday, with further strengthening Thursday. Northerly winds increase in response, and gale strength gusts will begin to develop in the southern waters Wednesday night in the southern waters. Gale strength gusts may expand into the northern waters, mainly south of Point St. George, Thursday afternoon.

FIRE WEATHER

Dry weather and above-normal temperatures through Tuesday, with generally lighter winds. Marine influence will again expand starting Tuesday, bringing cooler and more moist conditions. Temperatures will trend lower through the end of the week. West- northwest winds will strengthen behind a front on Wednesday. The interior ridges and channeled terrain will see stronger gusts of 20 to 30 mph. Locally higher gusts are likely south in Lake County. Good to moderate RH recoveries are expected to prevail for most of the area. Moderate recoveries in zones 419 and 421, with the locally gusty winds, will create elevated fire weather conditions Wednesday. A deeper trough will likely bring stronger winds Friday and into the weekend.

EKA WATCHES/WARNINGS/ADVISORIES

CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 9 AM PDT this morning for PZZ470- 475.