Get ready for hot temperatures, and the potential for active weather on the way in your Thursday forecast. High pressure to our east will continue to build west, and will help to usher monsoonal moisture into our region from the south over the next couple of days. That moisture moving into our region will bring the threat of thunderstorms back into our forecast for the afternoon and evening hours over the next several days. The best chance for thunderstorms will stay in our higher elevations, but there will be a slight chance for some active weather in the northern zones of the valley on Friday and Saturday. A Red Flag Warning for high fire danger is set to go into effect in western Siskiyou County from 2pm through 11pm Thursday due to the threat of thunderstorms, and a Fire Weather Watch has been issued for portions of Siskiyou and Modoc Counties from Friday afternoon through Friday night due to the threat of thunderstorms. Dry lightning, and locally gusty winds will result in higher fire danger in our higher elevations today through at least Saturday. An Excessive Heat Warning will be in effect for the west side of Siskiyou County from 11am Thursday through 11pm Friday, and a Heat Advisory will be in effect in Trinity County from 10am through 8pm Friday. Clouds are starting to increase from the south as we start your Thursday morning, and we'll fluctuate beteween mostly sunny to partly cloudy skies today. Temperatures are starting out in the 70's in the valley, 60's to 70's in the foothills, and 40's to 50's in most of our mountain areas early today. We'll have winds out of the north or northeast early this morning, but south winds will pick up again as we head into this afternoon. Air quality is very impacted in areas closest to the fire this morning, and those impacts are extending into the far east side of the valley in Butte County early today. South winds picking up this afternoon should help to limit air quality impacts in the valley, but will do very little to help air quality in the upper foothills and Plumas County this afternoon. The threat of thunderstorms will ramp up during our afternoon hours in all of our mountain areas, with the best chance for active weather in areas along the eastern slopes of the Sierra. Humidity is projected to end up in the 10 to 22 percent range in the valley this afternoon, but will likely stay a little higher in our mountain areas. High temperatures are projected to top out in the 103 to 108 degree range in the valley, with upper 80's to upper 90's possible in the foothills and Sierra, and mid 90's to lower triple digits projected for the Northern Mountains. The tricky part of our forecast for today is how much the smoke overhead will limit our heating heading into your Thursday afternoon. There is a good chance our high temperatures will fall short of projections in areas where smoke from the Dixie Fire is overhead.
Very similar conditions are expected across northern California on Friday, but the threat of thunderstorms will become slightly more widespread. Even the northern zones of the valley will have potential for thunderstorm activity Friday afternoon and evening. Winds will again start out out of the northeast in the morning hours, and then end up out of the south during the afternoon hours. We'll continue to have partly cloudy skies, and the potential for thunderstorms in the same areas of our region on Saturday, but temperatures are projected to dip by several degrees compared to the end of our work week. Valley areas will likely end up in the mid 90's to lower triple digits this weekend, while foothill and mountain areas top out in the 80's to 90's. The threat of thunderstorms will continue to be a concern for our fire danger through the weekend, but that threat is expected to taper off on Sunday. Any thunderstorms we do see forming could be accompanied by dry lightning and locally gusty winds. This is why we'd love to see showers, but thunderstorms are such a big concern. Low pressure approaching the coast will start to push the ridge to our east further to the east on Sunday. This will drive down our potential for thunderstorms and result in stronger winds out of the south. We'll have sunny to mostly sunny skies, average temperatures, and periods of gusty north winds early to mid week next week. Some modest cooling will be possible for the middle of next week, but we'll stay in a similar temperature range to the weekend on Monday and Tuesday.