textproduct: Eureka

KEY MESSAGES

* Elevated fire danger today in Trinity, Lake, and NE Mendocino Counties due to low RH and breezy winds.

* Near to slightly below normal interior temperatures expected through next week.

* Coastal stratus likely to form each night and clear each afternoon through at least mid next week.

SYNOPSIS

Near to slightly below normal temperatures likely for the interior areas, while near to slightly above normal coastal temperatures are likely for the coastal areas for the coming days. Breezy afternoon winds elevating fire danger in eastern Trinity, eastern Mendocino, and Lake Counties.

DISCUSSION

A weak upper level low off the coast of the Pacific Northwest continues to slowly move northwestward. This troughing pattern will bring a deeper marine layer with elevated stratus and possibly coastal drizzle over the coming days. Interior temperatures will remain about or slightly below normal with most valley seeing high 80s to mid 90s. A weak and deep marine inversion will bring elevated stratus to the coastal areas and extend fairly far inland overnight into the Eel, Klamath, and Trinity River valleys. Coastal temperatures will moderate somewhat, but could still reach slightly above normal depending on how fast stratus erodes to the coast in the morning and early afternoon. Low to mid 60s are generally expected for the immediate coast and high 60s to low 70s are likely just a few miles inland. Should the stratus erode early, the immediate coast may see high temperatures in the high 60s to low 70s.

The troughing pattern will also support breezy afternoon winds in the interior, especially in the higher terrain and channeled terrain in the afternoon. West winds could gust to 20 to 25 mph in these areas this afternoon. Relative humidity in the teens and 20s will support an elevated fire weather threat for eastern Trinity County, eastern Mendocino County, and Lake County. Relative humidity creeps upwards in the coming days, although winds will remain breezy most afternoons through early next week. /JB

AVIATION...(18Z TAFs)

Stratus has largely eroded to the immediate coastline, through some periodic impacts of IFR ceilings are possible into the mid afternoon at the coastal terminals. A deeper marine layer is expected overnight with stratus intruding into the interior river valleys. IFR to MVFR ceilings are expected at the coastal terminals. Outside the immediate coast and river valleys, VFR conditions are expected to continue for the next 24 hours. /JB

MARINE

Light winds continue across the waters with southerly winds being observed north of Cape Mendocino and northerlies south of the Cape. Seas are dominated by mid to long period northwesterly and southerly swells of 2 to 5 ft. Northerly winds start to increase south of Cape Mendocino Saturday night into Sunday, with sustained winds of 15 to 20 kts likely in the outer waters by Sunday evening. This pattern continues through mid next week. Wednesday, northerly winds increase again across the waters with strong breezes and steep seas expected for the outer waters. /JB

FIRE WEATHER

Breezy westerly winds are likely starting this afternoon for the interior areas and may be particularly breezy with gusts of 20 to 25 mph over the ridges and channeled terrain in eastern Trinity, northeast Mendocino, and Lake Counties. Afternoon RH today is forecast to be in the teens and 20s, which will bring an elevated fire weather threat. Relative humidities begin to rebound somewhat this weekend with most interior areas in eastern Trinity, northeast Mendocino, and Lake County seeing afternoon RH in the 20s with good overnight recoveries. This pattern continues through at least mid next week with only minor fluctuations in wind and RH each day. Closer to the coast, a deep marine layer will bring high RH and perhaps stratus and/or fog into the river valleys. Afternoon RH ranges from 70s to 80s at the immediate coast to 30s and 40s in interior Humboldt, Del Norte, and western Mendocino Counties. /JB/MKK

EKA WATCHES/WARNINGS/ADVISORIES

CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... None.