Monsoonal lightning is being predicted for some already dry and fire-plagued areas of Southern California later this week, as a heatwave prepares to settle in across much of the state.

A Heat Advisory is in effect starting Thursday morning at 10 am for much of the interior Bay Area, including the non-coastal Peninsula, all of the East Bay east of the hills, and much of Napa, Solano, and eastern Sonoma counties. You'll note that San Francisco is not included in there, and it seems like most of Marin County along with Richmond, Berkeley, Oakland, San Mateo, and towns on the ocean will be spared. This advisory extends through 10 pm Friday.

An Extreme Heat Watch was issued by the National Weather Service for the Central Valley south of Santa Clara and San Joaquin counties, and an Extreme Heat Warning is in place for the same period for San Luis Obispo and Santa Barbara counties.

A Red Flag Warning has been issued for San Luis Obispo and Santa Barbara counties starting Thursday morning and extending through Saturday morning, due to the possibility of lightning strikes and conditions that are ideal for rapid wildfire growth. Other areas around Los Angeles and the foothills of Ventura County are under a Red Flag Warning that starts on Wednesday.

While San Francisco could see a balmy high of 78 on Thursday, prompting some impromptu park and beach trips, other parts of the Bay Area will likely see more extreme temps.

The National Weather Service predicts a high of 107 in Concord on Thursday, and 101 in San Rafael, with a high of 93 in Santa Rosa. Temperatures cool down a bit Friday, and by Saturday, San Francisco's high is forecast to be 70, with the deep East Bay cooling into the 80s by Sunday.

Photo by Jo Dorais