A dead fish is seen in the mud on the median strip in the center of closed Route 51 in Pittsburgh, where Saw Mill Run flooded the street from heavy morning rains on Wednesday. Route 51 and Banksville Road remain closed into the evening.

PITTSBURGH — Pittsburgh and its southern suburbs cleaned up from flash flooding caused by heavy morning rains Wednesday, but a new round of late afternoon and evening storms left tens of thousands without power and reports of a tornado briefly appearing north of the city.

Duquesne Light reported about 30,500 customers without power as of 10 p.m. Wednesday and said damage due to numerous downed trees was hampering repairs. FirstEnergy’s West Penn Power reported a total of 21,335 customers without power at around 2 a.m. Thursday.

The tornado touched down south of New Castle at about 4:30 p.m. Wednesday as a new line of heavy storms moved through the region. The National Weather Service said barns were damaged, but there were no immediate reports of injuries.

Despite widespread Wednesday morning flash flooding that damaged homes and businesses and stranded some motorists following heavy rain in Pittsburgh and its suburbs, city and Allegheny County officials reported no fatalities or serious injuries.

The hardest-hit areas appeared to be the Route 51 corridor through the south part of the city and into the suburbs. Nearby areas, including Castle Shannon, Baldwin and Bridgeville, had some roads washed out and, as creeks overflowed onto low-lying areas, others were left caked in mud or littered with the occasional dead fish.

Three inches of rain or more fell in some areas Wednesday morning at the rate of 1 to 2 inches per hour. The saturated ground prompted emergency officials to warn drivers to avoid roads that flooded in the morning and to abide by barricades later in the day with more storms forecast.

Besides roads being closed as a precaution, others were impassable due to damage or debris, including a long stretch of Route 51 and Banksville Road, another key artery into the city’s southern suburbs.

“Even if the water recedes, the roadways are gone,” Pittsburgh Public Safety Director Michael Huss said, noting that some portions of both roads washed away.

During the worst of the morning flooding, Huss said the city’s swift-water rescue teams were responding to “several emergency and life-threatening situations.”

Once the rains ended by late morning, Allegheny County spokeswoman Amie Downs confirmed there were no deaths or serious injuries.