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. - Very slight chance for thunderstorms in northeast Trinity County Wednesday.

- Chance of rain for the North Coast Friday.

- Cooler temperatures & breezy winds likely late week into the weekend.

DISCUSSION

High pressure continues to build over Northwest California. 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 brief and partial clearing. Clearer skies are possible Wednesday with breezier winds off the coast.

Troughing to the north of the area today and Wednesday could bring additional chances of showers and thunderstorms to northeast Trinity County. This afternoon, 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%.

There is high confidence in a upper-level trough moving through the area Friday. Measurable rain is very likely in northern Humboldt and Del Norte, while chances of wetting rain (over 0.1") are around 60% in coastal Del Norte and 30% over coastal Humboldt. Outside a few sprinkles, the rest of the area is likely to remain dry. Despite the lack of rain in the interior, increased cloud cover and breezy winds will drop high temperatures 15 to 20 degrees in the interior with most areas in the 70s by Saturday. Saturday night, chilly temperatures are possible, especially for June. Frost may be possible in Hayfork and surrounding valleys with NBM showing around a 30% chance for low temperatures of 36 or lower.

Gusty westerly wind in Lake and southern Mendocino Friday is highly likely behind the frontal passage. NBM shows over 70% chance for gusts over 30 mph for much of Lake County, while the higher terrain and wind prone areas can see gusts over 40 mph. Similarly breezy winds are possible Saturday afternoon and evening, with around 50% chances for the lower elevations to see gusts over 30 mph. Sunday, widespread gusts ease, but the east side of Lake County could see gusty northeasterly winds. These conditions will need to be watched for a potential fire weather threat. Coastal areas are also likely to be breezy with gusts of 20 to 30 mph possible in the afternoons this weekend into early next week. JB

AVIATION...(18Z TAFs)

LIFR to IFR ceilings are likely to persist along the coast today. Some brief scattering and lifting is possible this afternoon, but stratus will likely be back by sunset. Building high pressure is likely to bring a shallower marine layer, bringing a higher potential for fog overnight. LIFR ceilings and visibilities are both possible along the coast. Most interior areas will likely see VFR conditions through the night outside of the near-coast river valleys. JB

MARINE

Northerly winds remain light to moderate today with the strongest winds in the lee of Cape Mendocino. Steep seas have been slow to subside in the outer waters, but wave heights are likely to drop below 8 ft this afternoon and evening. Much milder seas are found nearshore. Winds increase tonight into Wednesday with near- gale force gusts possible in the lee of Cape Blanco and Cape Mendocino. Winds nearshore will be much lighter, but steep seas of 5 to 8 feet are likely to propagate into the inner waters. Seas generally remain dominated by wind waves this week, with only minor mid to long period southerly and northwesterly swells. Winds ease again Thursday night into Friday as a cold front approaches the area. Seas will likely remain elevated as a steep northwesterly swell of around 6 to 8 ft at 9 seconds arrives Friday night into Saturday. Strong northerly winds are likely to return late Saturday into Sunday. JB

EKA WATCHES/WARNINGS/ADVISORIES

CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 3 PM PDT this afternoon for PZZ470-475.