textproduct: Eureka

SYNOPSIS

Dry weather along with near-normal temperatures are expected through the weekend. Breezy winds expand to the interior Friday through the weekend with low relative humidities bringing a fire weather threat. Light rain is possible for the North Coast Monday.

KEY MESSAGES

- Near normal temperatures and dry weather expected through the weekend.

- Widespread breezy to gusty winds each afternoon and evening Friday and through the weekend, with low RH values promoting locally elevated fire conditions across the interior.

- Chance for light rain for the North Coast Monday.

DISCUSSION

An upper-level trough will drive southward Friday and through the weekend, which is expected to cool temperatures 5 to 10 degrees. An associated weak cold front will track southward across the CWA on Friday, promoting widespread breezy west- northwest winds. Breezy conditions will prevail through the weekend, with the strongest winds over the coastal headlands and exposed ridges. Generally gusts from 25 to 35 mph are expected, with locally higher gusts. There is a 60-90% chances for gusts greater than 35 mph over the coastal headlands and higher terrain. Even lower elevations of Lake County could see gusts of up to 30 mph, and with low afternoon relative humidities, elevated fire weather conditions are expected. See the fire weather section for more details.

Ensemble clusters suggest a troughing pattern over the area through mid-next week. Precipitation chances (15-30%) of light rain return on Monday and gradually diminish on Tuesday. The highest chances for rain are for coastal Humboldt and Del Norte, but some sprinkles are possible for much of northwest California. Uncertainty remain high regarding to the amounts of precipitation over the area for this system. /ZVS/JB

AVIATION

Marine layers clouds have nearly dissipated as of this writing as northerly flow mixes in dry air across the region. Wind gusts in excess of 25 kt will be possible at the coastal terminals through the early evening with a very tight pressure gradient over the coastal waters. A trough approaching the Pacific Northwest will begin to weaken the pressure gradient overnight into Friday allowing the north winds to weaken. Thus, less gusty conditions are likely Friday afternoon. This may also allow the coastal clouds to be a little more persistent Friday in the Humboldt Bay area. RPA

MARINE

North winds are currently moderate to strong over the coastal waters with near-gale to gale force winds expected south of Cape Mendocino. Steep wind waves of 10 to 12 ft are possible south of the Cape, even nearshore. Farther north seas will be a little smaller where the upwind fetch is shorter. Overnight into Friday the winds will gradually decrease and seas will subside as a trough approaches the Pacific Northwest causing the pressure gradient to weaken. This trough will move past the West Coast over the weekend only to be reinforced by another trough early next week. This will cause winds to continue to weaken and potentially briefly turn out of the south Monday. Overall, this will cause improved conditions and much lower seas early next week. RPA

FIRE WEATHER

Gusty west-northwest winds are expected in interior areas each afternoon from Friday through Sunday. These winds combined with low afternoon relative humidities will promote elevated fire weather conditions. While the strongest winds are expected in the ridges where afternoon gusts could peak over 30 mph, lower elevations could see gusts of 20 to 30 mph each afternoon. In the eastern portions of the area (Trinity, eastern Mendocino, and Lake Counties), afternoon relative humidities are expected to drop into the low to mid 20s Friday afternoon. Terrain channeling in Lake County, especially, will bring locally critical fire weather conditions Friday afternoon and evening. Cooler temperatures, slightly higher relative humidity, and slightly lighter winds are expected Saturday and Sunday afternoons, but still an elevated fire weather threat is expected. Light rain is possible Monday and Tuesday of next week. /JB/ZVS

EKA WATCHES/WARNINGS/ADVISORIES

CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until noon PDT Friday for PZZ450.

Gale Warning until 6 AM PDT Friday for PZZ455.

Small Craft Advisory until 3 PM PDT Friday for PZZ470.

Gale Warning until 3 PM PDT Friday for PZZ475.