textproduct: Eureka

SYNOPSIS

High pressure continues to build over the area, bringing warm and dry conditions. Isolated thunderstorms are possible in northern Trinity County Wednesday afternoon. Rain is possible for the North Coast Friday.

KEY MESSAGES

- Warming trend for the interior will continue through Thursday.

- Troughing to the north of the area on Wednesday could bring chances of interior thunderstorms.

- Cooler temperatures, breezy winds, and a chance of rain is possible Friday.

DISCUSSION

High pressure continues to build over Northwest California today. Warm interior conditions with high temperatures for most valleys reaching the 90s. The warmest areas, along the Trinity and Klamath River Valleys, could see triple digits. This warming trend is likely to continue through Thursday. Coastal areas continue to see stratus continuing into the afternoon with only partial clearing. More clearing is possible Wednesday and with breezier winds off the coast.

Troughing to the north of the area on Tuesday and Wednesday could bring additional chances of thunderstorms to northeast Trinity County. Tuesday, confidence is very low as both moisture and instability remain meager, but an isolated rain shower may be possible. Confidence is very slightly higher Wednesday with a modest increase in moisture, but still chances remain at around 10%.

Ensembles are showing high confidence in a upper-level trough moving through the area late Friday. Rain chances have increased for the North Coast with NBM showing around a 50% chance for measurable rain for Humboldt and Del Norte Counties. Wetting rain (over 0.1") is around 50% in coastal Del Norte and 25% over coastal Humboldt. Outside a few sprinkles, the rest of the area is likely to remain dry; but increased cloud cover and breezy winds will drop high temperatures 15 to 20 degrees in the interior. Especially breezy westerly wind in Lake and southern Mendocino Friday are highly likely evening behind the frontal passage. NBM shows over 70% chance for gusts over 30 mph for much of Lake County, while the higher terrain can see gusts over 40 mph. This will need to be watched for a potential fire weather threat. Otherwise, chilly nights, especially for June, are likely behind this frontal passage with mid to high 30s possible for the coldest interior valleys. JB

AVIATION...(18Z TAFs)

LIFR ceilings being observed at the coastal terminals are likely to be persistent for much of the day. Some lifting to IFR and brief scattering is possible this afternoon. Otherwise, LIFR ceilings and visibilities are possible again tonight for the coast. Inland areas, aside from a few near-coast river valleys, are likely to remain VFR. JB

MARINE

Northerly winds gradually ease today, especially nearshore and seas are expected to gradually ease as well. Winds continue to diminish Tuesday, but could still be breezy in the lee of Cape Mendocino. Stronger northerly winds with near-gale to gale force gusts briefly return Wednesday. Winds ease again late week as a general troughing pattern sets up. Stronger northerly winds return this weekend. Seas this week remain dominated by wind waves and small long period northwest and southerly swells. JB

EKA WATCHES/WARNINGS/ADVISORIES

CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 3 PM PDT this afternoon for PZZ450-475.

Small Craft Advisory until 9 PM PDT this evening for PZZ470.