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 through 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

A weak trough is moving through the area this afternoon and bringing some fairly thick high clouds. These are moving out of the area. The CAMS are showing some light showers developing in Siskiyou county, but moving north and away from the area. Tonight the marine is expected to return, although it isn't expected to be particularly deep. 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 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 starts 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. So confidence remains low, but there is the potential for thunderstorms and will continue to message the threat. As this system moves by the area winds are expected 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

The marine clouds have pushed off the coast from KCEC and KACV, but this is expected to shortlived. The Mendocino coast continues to be cloudy. Tonight widespread stratus is expected along the coast again and this is generally expected to be LIFR in most areas. There is the potential for KACV and KCEC to drop to 1/4 mile at times overnight. Tuesday the models show some clearing in the afternoon, but this looks like it will be only for a few hours in the afternoon. MKK

MARINE

Northerly wind have diminished this afternoon and are around 15 to 20 kt. The 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. The northwest winds this afternoon have pushed some of the smoke out of Southern Humboldt and out of the Trinity river valley of Big Bar. Tonight smoke is expected to spread back into southern Humboldt and more of the Trinity river valley. Tuesday is generally expected to see similar smoke conditions to today. MKK

EKA WATCHES/WARNINGS/ADVISORIES

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