textproduct: Eureka

KEY MESSAGES

* Smoke remains over areas outside of the marine layer due to local and distant wildfires.

* Interior temperatures are expected to remain near normal through the first half of the week with highs in the low to mid 90s.

* Another trough is expected to bring below normal temperatures and the potential for a few thunderstorms late in the week.

SYNOPSIS

A series of upper level troughs off the West Coast are expected to generally keep inland temperatures near normal. Persistent marine clouds expected along the coast with some afternoon clearing. Late in the week, a stronger trough will bring cooler inland temperatures and even the potential for inland thunderstorms.

DISCUSSION

Tuesday the ridge is expected to build slightly over the area. The marine clouds are expected to push back to the coast in afternoon, but once again it may be hard to clear out right at the coast for very long. Inland temperatures are generally expected to be in the mid to upper 90s or even 100 in he warmest valleys. Wednesday may start to see a few degrees of cooling here and there, especially closer to the coast as the marine layer may deepen slightly.

Thursday several more degrees of cooling are expected as an upper level trough begins to approach the area. This will likely deepen the marine layer.

Thunderstorms are possible Friday as the trough deepens and starts to move past the area just off the coast. Currently, two of the four ensemble clusters are showing some instability Friday afternoon. Confidence remains low, but there is potential for thunderstorms. This will be monitored. As this system moves by the area, winds are anticipated to increase in the afternoon and evening over the interior areas. This trough will also bring cooler temperatures on Friday with most of the area remaining below normal. Saturday temperatures are expected to remain below normal before starting to warm up on Sunday. MKK

AVIATION

Widespread stratus continues to redevelop along the coast early this morning with LIFR conditions expected for coastal terminals. KACV and KCEC should drop to 1/4 mile visibility at times. Tuesday, the models show some clearing in the afternoon, but this looks like it will be only for a few hours in the afternoon. VFR conditions are expected for interior terminals with periods of high clouds.

MARINE

Wind driven waves/fresh swell remain somewhat larger, around 6 to 8 feet at 8 seconds. A small southerly swell continues around 3ft@17s.

High pressure briefly returns Tuesday and Wednesday which will increase northerly winds to around 20 to 25 kt. Thursday and Friday, another upper trough is expected to flow over NW CA causing winds to diminish again with the potential for local southerly winds near the coast. MKK

FIRE WEATHER

The main challenge for the fire weather forecast is the potential for thunderstorms late in the week. Tuesday through early Thursday, weak high pressure is expected to bring dry and fairly stable conditions. Winds will generally be terrain driven with with typical northwest breezes in the afternoon. Thursday night into Friday, another trough is expected to approach the area. At this point it is still hard to tell if the moisture instability and lift will line up to get thunderstorms, but it is possible. This will continue to be watched through the work week. Also, this trough may bring some breezy winds in the afternoon on Friday.

Smoke was impacting portions interior Humboldt as well as the Trinity River Valley. Early this morning, smoke is expected to spread back into southern Humboldt and more of the Trinity River Valley. MKK

EKA WATCHES/WARNINGS/ADVISORIES

CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 9 PM PDT Wednesday for PZZ470- 475.