Be prepared for the heat to continue and the threat of mountain thunderstorms to persist across the northern Sierra and Southern Cascades today. High pressure off to our east continues to keep our region hot today, but some influence from the Delta Breeze will result in a modest temperature drop in most of our lower elevations this afternoon. We have mostly clear conditions over northern California this morning, and we'll have plenty of sunshine on the way in your Thursday forecast. There will be potential for afternoon and evening thunderstorm activity in the northern Sierra and southern Cascades this afternoon and evening. Temperatures are starting out in the 60's to 70's in the valley and foothills this morning, while our higher elevations are mostly starting out in the 50's. We'll continue to have winds out of the south to 15mph in the valley and foothills. Southwest winds to 15mph, and gusts to 25mph will be possible in portions of the northern Sierra and southern Cascades today. This will result in elevated fire danger in areas of Lassen, Modoc, and Plumas Counties this afternoon and evening. Humidity will dip into the 17 to 29 percent range today, which is up slightly compared to Wednesday. High temperatures are projected to top out in the 96 to 103 degree range in the valley, and mid 80's to mid 90's in most mountain and foothill areas this afternoon. Our fire danger stays in the moderate to high range due to our dry fuels, and our fairly dry airmass overhead. The stronger winds and the threat of thunderstorms in our higher elevations will also bring fire danger concerns today.
Not much is going to change in our forecast through this weekend, but tempratures are expected to get slightly hotter as the influence from the Delta Breeze diminishes. Temperatures will end up slightly hotter on Friday, and we'll end up in the upper 90's to around 107 degrees in the valley through your 4th of July Weekend in the valley. Mountain and foothill areas will continue to have high temperatures topping out in the 80's to 90's through your extended forecast. There will be potential for northern Sierra and southern Cascades thunderstorms on Friday, and then the threat of thunderstorms will become slightly more widespread on Saturday. This could even include portions of the north valley, the Shasta County Mountains, and we could even potentially see thunderstorm activity as far west as Trinity County. Sunday is not currently expected to be as active, but the threat of thunderstorms will continue. The trend of hot and dry weather will persist as we head through next week.