textproduct: Eureka

KEY MESSAGES

* A weak frontal system arriving Wednesday will likely lead to cooler temperatures and a few showers or thunderstorms.

* There is a slight chance for thunderstorms in mainly in Trinity, Humboldt and Del Norte counties on Wednesday.

* Warmer temperatures and dry conditions return end of the week.

SYNOPSIS

An upper level low will bring cooler temperatures and a chance for showers and thunderstorms Wednesday and possibly Thursday. Warmer and drier conditions are expected Friday and into the weekend.

DISCUSSION

An upper level low dropping south over the area is expected to impact the area Wednesday and Thursday. This is expected to bring some showers and possible thunderstorms to the area Wednesday afternoon and evening. The models have come into better agreement on the location of this low and the instability. The Hires models are showing a number of showers moving through the area WEdnesday afternoon. These may continue overnight, although confidence is low on whether there will be enough instability for thunderstorms overnight. The GFS does keep 100 to 150 j/kg of MU CAPE over northern Humboldt and Del Norte counties through much of Thursday night. These storms are not expected to be particularly dry, but there certainly may be strikes that occur on the edge of the rainfall cores.

Thursday evening the low is expected to move out of the area, although this may be slower than currently expected. Still any showers or thunderstorms should end by sundown on Thursday.

Friday and into the weekend high pressure is expected to build into the area bringing a return of warm and dry conditions. Winds are expected to remain fairly light and the marine layer is likely to be fairly persistent. MKK

AVIATION

Stratus developed along the coast this morning and has mostly cleared out this afternoon. Tonight this stratus is expected to return MVFR to IFR conditions, quickly at ACV and more slowly in KCEC. Wednesday skies are expected to clear out again along the as the an upper level low moves overhead and weakens the inversion. This may also bring a few thunderstorms to interior Humboldt and Del Norte counties as well as Trinity county. MKK

MARINE

The northerly winds persist across the outer waters and near the capes. A local area of southerly winds has developed just close to the coast near Crescent City. It is uncertain on when this will expand, but it is likely to expand by Wednesday afternoon. The northerlies are also expected to diminish through the afternoon on Wednesday as southerly winds spread across the area. These light southerly winds are expected to persist on Thursday. Locally stronger winds are expected near Crescent City, especially in the evening. Friday the winds are expected to become northerly again and increase over the weekend. MKK

FIRE WEATHER

High pressure building off the coast will continue the warming and drying trend across Northwest California today. Wednesday afternoon or overnight an upper low entering over Del Norte, Humboldt, and N. Trinity counties has the potential to cause a few thunderstorms. There is still a lot of uncertainty on the details of these storms, yet the most likely scenario seems to be storms forming over the Salmon, Klamath, and Trinity Alps before flowing towards the coast. Confidence is slowly increasing that there may be some storms with the models becoming increasingly confident if the track up the upper level low. There will likely be rain with each of these storms, yet some lightning that strokes away from the core of the storm could start a fire. It is possible that the there could be a few storms on Thursday, but these are expected to be limited to northern Trinity county and Siskiyou county. Warmer and drier weather along is expected to return Friday and Saturday. MKK/DS

EKA WATCHES/WARNINGS/ADVISORIES

CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 9 AM PDT Wednesday for PZZ450.

Small Craft Advisory until 8 PM PDT Wednesday for PZZ455- 470.

Small Craft Advisory until 3 AM PDT Thursday for PZZ475.