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.

Scattered storms are on the move with periods of heavy rainfall and it's expected to last into the early morning hours of Thursday.