NEVADA COUNTY (CBS13) — Portions of Nevada County are under an evacuation advisory due to Sunday’s incoming storm.

The National Weather Service has issued a Flash Flood and Debris Flow Watch through Monday. Heavy rain is possible over the River Fire burn scar, which could create ash and debris flows.

READ MORE: Vegetation Fire In Vacaville South Of Winters Dubbed Quail Fire, Evacuation Warning In Effect

Debris flows occur over recently burned areas where is no longer vegetation to absorb water and keep soil in place.

READ MORE: 2 Grass Fires In Elk Grove And Galt

Additionally, a fast-moving mix of mud, ash, and debris can form and move downslope even faster than one could run or drive, according to the Nevada County Office of Emergency Services.

MORE NEWS: Two Vehicle Accident Requires Extrication In South Lake Tahoe

The areas under an advisory are located west of Colfax.