The latest heat wave is bringing triple-digit temperatures to the interior of Southern California and elevated fire danger to the southern Sierra Nevada.
The National Weather Service says the heat arriving Thursday and building into the weekend results from high pressure over the desert Southwest that's moving westward.
Spiking temperatures will be accompanied by elevated moisture moving up from Mexico that could add humidity to the heat wave.
In the Sierra, fire danger warnings are posted from Sequoia to Yosemite, while flood warnings due to snowmelt are posted in northern Mono County in California and southern Lyon County in Nevada.
To the south, there's a red flag warning for Santa Barbara County's mountains and south coast due to predicted "sundowner" winds starting Thursday evening.