(MOAB, Utah) — Monsoon rains are causing a flash flooding threat to linger over a large swath of the Western U.S. following several flooding events overnight.

Flash flood events were reported over the desert Southwest Saturday night into Sunday morning, with Moab, Utah, experiencing flooding that spilled from streets to businesses and mud piling up on storefronts.

In New Mexico’s Carlsbad Caverns National Park, more than 100 people were evacuated after being stuck for hours due to impassable roadways.

More than 12 million people from Arizona to Louisiana were under flood alerts on Sunday morning.

Drought conditions in the region are causing the sudden burst of rain to mix with the parched soil as if it were concrete, leading to flash flooding.

The megadrought combined with record heat is also increasing fire threats farther west.

Dry conditions and hot temperatures are continuing in the Pacific Northwest. Fire weather watches have been ordered for northeastern Oregon and southern Washington due to the potential for abundant lightning, and a fast-growing wildfire has sparked in the Klamath National Forest in Northern California.

Farther south, record highs were tied in Redding and Sacramento, California, on Saturday at 110 degrees and 106 degrees, respectively.

Hot temperatures are expected to continue in the region on Sunday.

Copyright © 2022, ABC Audio. All rights reserved.