Hot and mostly dry conditions are on the way in your Tuesday forecast, and a Heat Advisory is now in effect for the valley, foothills, and Trinity County. Siskiyou County will also be under a Heat Advisory from 10am through midnight tonight. Trinity County will have their Heat Advisory expire at 10pm tonight, but the Heat Advisory in the valley and foothills is set to stay in effect through 8pm on Saturday night. Skies are clear for the start of your Tuesday and temperatures are very warm this morning. Valley and foothill areas are starting out in the 70's, while most mountain areas are starting out in the 50's. Winds are mostly light and out of the Northeast this morning, but are expected to pick up to around 10 to 15mph out of the South this afternoon. Humidity has recovered well overnight and is mostly above 60 percent in the valley to start the day, but will more than likely dip into the teens this afternoon. High temperatures are projected to top out in the 100 to 108 degree range in the valley this afternoon, while foothill and Sierra locations end up in the mid to high 90's, and the Northern Mountains top out in the 90's to triple digits this afternoon. High pressure centered to our Southeast continues to be the main driving factor in our forecast, but an area of low pressure moving into the Pacific Northwest will have some influence over our conditions today. That influence will be a very modest drop in temperatures from Monday, and the potential for some thunderstorm activity in higher elevations closest to the Oregon border and in portions of the Sierra.
A very similar setup is expected on Wednesday, but we'll add a few more high clouds into the mix. Temperatures will be roughly the same as what we'll see on Tuesday, and we'll continue to have the threat of thunderstorms in portions of the Sierra. Low pressure will be moving off to our Northeast on Thursday, and high pressure will become stronger across our region. That will result in dry weather, sunny skies, and hotter temperatures on the way for your Thursday and Friday. Valley areas will start out in the 70's and end up in the 105 to 110 degree range late this week, while foothill areas start out in the 70's and end up in the mid 90's to triple digits. Mountain areas can expect low temperatures in the 50's, and high temperatures in the mid 90's to triple digits on Thursday and Friday.
High pressure will begin to weakend and move East as we head into your weekend and area of low pressure will be dropping into our region from the Pacific Northwest. This will result in a modest drop in temperatures on Saturday and a decent drop in temperatures on Sunday. High temperatures on Saturday will top out in the high 90's to low triple digits, while foothill and mountain areas end up in the high 80's to low 90's. Valley temperatures will then end up in the low to mid 90's on Sunday, while foothill areas end up in the low to mid 80's, and mountain areas end up in the 70's to 80's. Breezy winds out of the North are also expected to develop, which could result in slightly elevated fire danger for the latter half of your weekend. There will also be a slight chance for some shower and thunderstorm activity developing in mountain areas on Sunday afternoon. Monday will be similar to Sunday, but high temperatures are projected to be a couple of degrees cooler.