From Hazel to Floyd to Sandy, the City of Brotherly Love has endured some great storms. Yet somehow, a rather modest mid-summer front managed to put down over 8 inches of rain in Philadelphia Sunday, giving the city its greatest daily deluge in over 140 years of weather records.
The 8.02 inches of rain that fell easily exceeded the previous single day record in Philadelphia of 6.63 inches from September 16, 1999 during hurricane Floyd. The whopping total pushed its July rainfall over 13 inches, making it the wettest July on record by a healthy margin. The previous July record was the 10.42 inches that rained down in 1994.
Rainiest months on record in Philly — July 2013 is now 2nd all-time as of 5 AM. pic.twitter.com/1SCZMS6WQt
— Phillyweather.net (@phillywx) July 29, 2013
Incredibly, 7.35 inches of the Sunday’s 8.02 inches fell in 4.5 hours (source @WxNick on Twitter) !
The rain can be blamed on a strong push of moist tropical air ahead of a slow-moving cold front (and a strong jet stream at high altitudes). In this humid, unstable air, strong thunderstorms developed in long, train-like formations, oriented from southwest to northeast. The storms then tracked over the same locations with unrelenting downpours.
Unlike a tropical storm, whose heavy rain often leaves a massive footprint, Sunday’s heavy rains were very localized, falling in a fairly narrow ribbon from Philadelphia into some of its eastern suburbs in southwest New Jersey.
“South Jersey, the southeastern half of Philadelphia, and down into Wilmington were the “winners” in the rainfall game as training set up shop and ran over the same real estate,” explains the blog PhiladephiaWeather.net.
Consider, also, Baltimore and Washington received just a trace of rain, and New York city logged less than a quarter inch.
The rain in Philadelphia and its eastern suburbs caused street flooding and, at Philadelphia International Airport, all American Airlines flights are cancelled through at least noon today due to power problems caused by the rain.
Here are a few images of the flooding, from Twitter:
— the Weatherboy (@theWeatherboy) July 28, 2013
We are live at 6pm with some major flooding. At least a dozen cars are stranded in the middle of I-76 in Mt. Ephraim pic.twitter.com/qSoEtt6Y8N
— Chris O'Connell (@CoconnellFox29) July 28, 2013
— Gary Leader (@Pmroads) July 28, 2013