The heat persists and even intensifies across Northern California on Friday. High pressure along the coast from the Pacific continues to be the dominant driving factor in our forecast, and we'll have little to no influence from the low pressure area off to our East that brough thunderstorms to the Sierra over the last few days. A Heat Advisory is currently in effect for the valley, foothills, and Trinity County. The valley and foothills will continue to have the advisory in place through 8pm Saturday evening, while the advisory in Trinity County is set to expire at 10pm tonight. An addiitonal Heat Advisory will go into effect in Siskiyou County at 11am this morning and is set to expire at 11pm tonight. Temperatures are starting out in the 70's in the valley and foothills this morning, and in the 50's to 60's in the mountains. Winds are modest and out of the Northeast early today, but will shift to become out of the Southeast this afternoon. Skies will be sunny and humidity is expected to dip into the 7 to 25 percent range this afternon. High temperatures are projected to top out in the 105 to 111 degree range in the valley, while foothill and mountain areas end up in the 90's to triple digits. Fire danger is mostly expected to stay in the moderate range, but could be a little higher in northern portions of the valley and surrounding foothills this afternoon.
Low pressure dropping down from British Columbia to the Pacific Northwest will brush by to our North as we head through your weekend and that will result in cooler temperatures and stronger winds. Low temperatures will still be very warm on Saturday, but high temperatures are projected to fall by around 5 to 10 degrees compared to Friday. Valley areas will end up in the high 90's to around 102 degrees, while foothill and mountain areas top out in the high 80's to mid 90's. Sustained winds out of the West will be up to around 20mph on Saturday afternoon, and gusts could be up to aorund 30mph as the low pressure drops down from the North. Humidity will also stay relatively low, which will result in higher fire danger this weekend. Sunday will be much cooler than Saturday, but winds will be slightly stronger out of the Northwest. Sustained winds to 25mph will be possible, and gusts could reach up to around 35mph. Fire danger will be somewhat higher on Sunday. Temperatures will start out in the 60's in the valley on Sunday and will end up in the high 80's to low 90's in the afternoon. Foothilll and mountain areas will top out in the mid 70's to low 80's on Sunday. We'll also have a slight chance for some Sierra showers on Sunday evening.
Monday will be very similar to Sunday, but winds will be slightly weaker. Temperatures will end up in the same range as Sunday on Monday afternoon. High pressure will rebuild over Northern California towards the middle of next week and that will result in another warming trend on the way, but that we are not expected to be anywhere near as hot as this week. Valley areas will end up back in the mid to high 90's by the middle of next week. Mountain and foothill areas will mostly end up in the mid 80's for the middle of next week, but we could see 90's return to the Northern Mountains by Wednesday.