Not much is changing in your forecast today. A weak area of low pressure is centered just to our south and a strong ridge of high pressure is off to our east. Another short-wave will track north across our region this afternoon and that will bring a chance for light showers and thunderstorm activity to higher elevations this afternoon and evening. High pressure off to our east is keeping temperatures around or just slightly below average for this time of year. The most likely area for thunderstorm activity today will be in Plumas, Lassen, and Modoc Counties, but there will also be a chance for some thunderstorm activity in the Northern Mountains this afternoon and evening.
Skies are mostly clear of clouds to start the day over northern California, but smoke continues to blanket our region this morning. Air quality is still in the unhealthy range for most of our region, but has modestly improved compared to the start of your Tuesday. Some parts of the mid valley are starting out with air quality in the moderate to unhealthy for sensitive groups range. Temperatures are starting out in the 60's to 70's in the valley and foothills, whlie mountain areas are in the 40's to 50's to start the day. Winds are mostly out of the east this morning, but will shift to become out of the south to 10mph again this afternoon. Humidity is expected to be slightly higher this afternoon, with most areas ranging from around 25 to 40 percent this afternoon. That is a noteworthy improvement compared to the last few days, and will help to keep fire danger back into the moderate to high range this afternoon. High temperatures will mostly end up in the mid 90's in the valley this afternoon, while foothill and mountain areas end up in the mid 80's to lower 90's. The threat of thunderstorms will return to higher elevations this afternoon, with the best chance resting in the northeastern zones of our region.
High pressure to our east will be the dominant feature in your late week and weekend forecast, and will usher in a warming trend from Friday through Sunday. Valley areas will climb into the upper 90's to low triple digits, while foothill and mountain areas will end up in the upper 80's to mid 90's. Active weather will be possible in higher elevations for the afternoon and evening on Friday and Saturday, but the latest models aren't showing much happening during that time. Low pressure tracking through to our north is expected to bring another modest drop in temperatures into our forecast for the start of next week. Valley areas are currently projected to end up in the mid to upper 90's on Monday and Tuesday, while mountain and foothill areas range from the mid 80's to low 90's.