LAS VEGAS (KTNV) — Many residents of the Las Vegas Valley woke up Wednesday morning to a sky full of smoke and ash.

It’s wildfire season in the West, and there are several in the region sending bad air our way. Three large fires in Southern California in particular are likely to be the culprits.

Fire at airport
Estimated size: 22,000 acres as of 4 a.m. Wednesday
Location: Santa Ana Mountains, northwest of Murrieta

Line fire
Estimated size: 34,000 acres as of 4 a.m. Wednesday
Location: San Bernadino Mountains, northeast of Riverside

Bridge fire
Estimated size: 46,000 acres as of 4 a.m. Wednesday
Location: San Gabriel Mountains, northwest of Riverside

The smoky air prompted the Clark County Division of Air Quality to issue a warning Wednesday for polluted air in Southern Nevada.

Officials warn that particles in wildfire smoke can aggravate respiratory conditions such as bronchitis, asthma and heart disease.

“Under the current circumstances, it may be best for children, the elderly and people with respiratory and heart conditions to stay indoors,” they advise.

Computer models predict that the thick plume of smoke will pass just east of Las Vegas on Wednesday afternoon, but will linger in southern Clark County in places like Searchlight and Laughlin. Winds are expected to blow from the southwest or west over the next few days, meaning that wildfire smoke could potentially blow from Southern California into Southern Nevada during that time and be worth keeping an eye on.