A severe thunderstorm with strong winds and heavy rain that hit the Mahoning Valley Sunday afternoon brought major flooding and power outages in both Mahoning and Trumbull counties.

Mahoning County was hit hardest by the storm, with reports of many fallen trees, toppled and downed power lines and flooded roads throughout the county. Areas of Austintown, Boardman and Canfield reported the most flooding, storm damage and power outages.

In Boardman, many roads were not passable because of high water tables and fallen trees and power poles across roads.

Because of the damage, Boardman fire Chief Mark Pitzer issued a warning to residents to stay in their homes because of the amount of storm damage and excessive flooding.

Trees were uprooted at Forest Lawn Cemetery between Market Street and Glenwood Avenue in Boardman. Residents were asked to avoid areas such as Shields and Tippecanoe roads where there was an excess of downed trees and powerlines.

Boardman firefighters reported about 1 foot of water at the intersection of South Avenue and Route 224.

On Sunday afternoon, about 27,000 Mahoning County residents, mostly in Austintown and Boardman, were without power, according to Ohio Edison. By late in the evening, about 18,000 were still without power. Six hundred outages were reported in Trumbull County.

The Mahoning County Emergency Management Agency and Boardman firefighters asked residents of Boardman and Canfield to stay home to allow work crews to clean up damage from fallen trees and flooding.

Trumbull County also saw a lot of flooding following the storm.

A spokesman with the Trumbull County 911 Center said they received numerous calls of flooding on many roads, including Route 46. The spokesman said many lanes of the road were difficult to pass through.

A flash flood watch remained in effect until 10 p.m. Sunday for Mahoning, Trumbull and Columbiana counties. Earlier in the day, there was a flash flood warning issued for the area.

The National Weather Service will conduct a storm survey Monday across Mahoning County to determine if a tornado touched down in the area. The National Weather Service in Cleveland is forecasting more rain for the area with a 70% chance Monday and 50% chance Tuesday.