Officials urged Ventura and L.A. County residents affected by recent wildfires to brace for possible mudslides on Wednesday, when a storm system is expected to dampen southwest California.

According to the National Weather Service, a Pacific storm system will likely bring light to moderate rainfall across the region. There’s also a slight chance of heavy showers late Wednesday afternoon into the night in areas including those affected by the Woolsey and Hill fires.

Forecasters said they expect about a quarter to an inch of precipitation, which would likely lead to rockslides and mudslides, particularly on Highway 1 and canyon roads. Officials also warned of major traffic delays.

As of Sunday morning, the deadly Woolsey Fire that erupted on Nov. 8 near Simi Valley and made its way south to Malibu has burned nearly 100,000 acres and was 88 percent contained.  The Hill Fire, which ignited the same day in Santa Rosa Valley, scorched 4,531 acres and was fully contained.

In January, the mudslides that struck Montecito a month after the Thomas Fire exploded killed 21 people.

“Much like Montecito, the orders will be ‘evacuate,’ and you need to evacuate if you get that,” Cal Fire Thom Porter previously said.

Sandbags for residents are available in several fire stations, including Ventura County fire station 33 in Thousand Oaks and station 36 in Oak Park.

The city of Thousand Oaks’ Municipal Service Center is also offering pre-filled sandbags. L.A. County residents can enter their address on this page of the county website to find the nearest site to pick up free sandbags.

Thousand Oaks officials provided this homeowner’s guide to using sandbags during weather events.