A tornado warning is in effect for Philadelphia and parts of southeastern Pennsylvania, including Montgomery, Chester, Delaware and Bucks Counties until 5:45 p.m, the National Weather Service says.Tuesday's weather forecast brings two distinct risks to the Philadelphia region — we've issued a NEXT Weather Alert for excessive heat during the day and chances of storms at night.

Downpours set off flood warnings Wednesday night for Philly and surrounding areas, and most of Chester County and northern Delaware.

"Flash flooding of small creeks and streams, urban areas, highways, streets and underpasses as well as other poor drainage and low-lying areas."

North Carolina remains second only to Florida in CSU's projected landfalling storms index.