Heat advisory issued for upcoming triple-digit heat in Southern California

A significant warm-up is coming to the Inland Empire and parts of San Bernardino and Riverside County valleys.

KCAL News has issued a Next Weather Alert for this Thursday and Friday in preparation for the incoming heat. The alert will affect Inland Empire communities in the deserts and valleys, as well as residents living in the Southern California mountains and non-coastal areas in Los Angeles, Orange, and Ventura counties.  

The National Weather Service has issued a heat advisory ahead of the upcoming weather. The advisory will go into effect at 10 a.m. Wednesday and remain until 8 p.m. Friday.

Forecasters predict Thursday will be the hottest day of the week, with most areas of Southern California experiencing temperatures 5 to 10 degrees above normal. The NWS says areas like the San Gabriel Valley, San Fernando Valley and Calabasas will have temperatures 10 to 12 degrees above normal. Maximum temperatures in the valleys could reach up to 106 degrees.

As temperatures rise, so will the risk of fire danger. The NWS says there will be "abnormally elevated fire behavior and growth with risk of plume dominated fires."

Weather officials are also warning communities that the high temperatures may cause heat-related illness.