Flash Flooding and Flood in Pennsylvania, May 24, 1999

A pair of thunderstorms brought very heavy downpours across extreme southeast Pennsylvania. The second in the series occurred too quickly on the heels of the first set of storms. The ensuing heavy rain caused considerable urban and poor drainage flooding as well as flooding of streams within Philadelphia and lower sections of Montgomery and Bucks Counties. Storm totals averaged between 2 and 3 inches, most of which fell within two hours. Within Philadelphia, 2.06 inches of rain fell in two hours in Northeast Philadelphia between 1030 a.m. and 1230 p.m. EDT. The Frankford Creek at Castor Avenue exceeded its estimated flood stage of 7 feet from 11 a.m. EDT until 1215 p.m. EDT. It crested at 8.37 feet at 1130 a.m. EDT. The basement of Saint Agnes Hospital was flooded. In Montgomery County, several major roadways were flooded including Philmont Avenue in Lower Moreland Township. In Delaware County, the heavy rain caused the partial collapse of a Ridley Township health club's roof at Noon EDT. The gutters clogged and a 35 foot section of the roof collapsed. No injuries were reported. In Bucks County, a combination of stream and urban flooding was reported in Northampton, Southampton and Falls Townships and Bristol and Tullytown Boroughs. In Bensalem, clogged sewers backed up and caused flooding. Storm totals included 3.04 inches in Wynnewood (Montgomery County), 2.83 inches at the Franklin Institute within Philadelphia, 2.72 inches in Neshaminy Falls (Bucks County), 2.70 inches at the Northeast Philadelphia Airport, 2.55 inches in Southampton (Bucks County), 2.52 inches at the Philadelphia International Airport and 2.40 inches in Crum Creek (Delaware County).