Bands of showers and isolated thunderstorms with heavy rain moved through the region on the 23rd. They caused poor drainage, creek and river flooding in southeastern Pennsylvania from the morning of the 23rd into afternoon of the 24th. The Brandywine Creek Basin had the most widespread flooding. The heaviest rain fell during the late morning and evening on the 23rd. Event precipitation totals averaged two to four and a half inches with the axis of heaviest rain across northwest Chester and Montgomery Counties and southeast Berks County.

Flood in CHESTER, PENNSYLVANIA
From 23-SEP-11 18:07:00 to 24-SEP-11 16:16:00 (EST-5)
Location: HONEY BROOK
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: River/Stream Gage

The runoff from the heavy rain on the 23rd caused numerous creeks in Chester County to flood with minor to moderate flooding occurring. The West Branch of the Brandywine Creek at Honey Brook had moderate flooding and was above its 7 foot flood stage from 707 p.m. EDT  on the 23rd through 310 a.m. EDT on the 24th. It crested at 10.65 feet at 930 p.m. EDT on the 23rd. Farther downstream, the West Branch of the Brandywine Creek at Coatesville was above its 7 foot flood stage from 757 p.m. EDT  on the 23rd through 5 a.m. EDT on the 24th. It crested at 7.82 feet at 2 a.m. EDT on the 24th. The East Branch of the Brandywine Creek below Downingtown had moderate flooding and was above its 7 foot flood stage from 1049 p.m. EDT  on the 23rd through 358 a.m. EDT on the 24th. It crested at 9.91 feet at 1115 a.m. EDT on the 24th. The main stem of the Brandywine Creek at Chadds Ford was above its 9 foot flood stage from 342 a.m. EDT through 516 p.m. EDT on the 24th. It crested at 10.91 feet at 1045 a.m. EDT.  The French Creek at Phoenixville was above its 8 foot flood stage from 1140 p.m. EDT on the 23rd through 926 a.m. EDT on the 24th. It crested at 9.62 feet at 3 a.m. EDT on the 24th. The Valley Creek at Valley Forge was above its 7 foot flood stage from 957 p.m. EDT  on the 23rd through 202 a.m. EDT on the 24th. It crested at 7.65 feet at 1115 p.m. EDT on the 23rd. Event precipitation totals included 4.39 inches in Nottingham, 2.97 inches in Unionville and 1.63 inches in West Chester.

Flood in PHILADELPHIA, PENNSYLVANIA
From 23-SEP-11 20:45:00 to 24-SEP-11 01:00:00 (EST-5)
Location: FOX CHASE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: River/Stream Gage

Heavy rain caused flooding along the Pennypack Creek. The Pennypack Creek at the Rhawn Street Bridge was above its 7 foot flood stage from 945 p.m. EDT on the 23rd through 2 a.m. EDT on the 24th. It crested at 8.45 feet at 1230 a.m. EDT on the 24th. Event precipitation totals included 2.35 inches at the Philadelphia International Airport, 2.20 inches in Wyndmoor and 1.82 inches in Rockledge.

Flood in BERKS, PENNSYLVANIA
From 23-SEP-11 19:43:00 to 24-SEP-11 04:04:00 (EST-5)
Location: MANATAWNY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: River/Stream Gage

Heavy rain caused moderate flooding along the Manatawny Creek. The Manatawny Creek near Spangsville was above its 6 foot flood stage from 843 p.m. EDT on the 23rd through 504 a.m. EDT on the 24th. It crested at 7.31 feet at 1 a.m. EDT on the 24th. Event precipitation totals included 3.80 inches in Birdsboro, 2.98 inches in Oley and 2.04 inches in Fleetwood.

Flood in MONTGOMERY, PENNSYLVANIA
From 24-SEP-11 03:12:00 to 24-SEP-11 09:09:00 (EST-5)
Location: ABRAMS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: River/Stream Gage

The runoff from the heavy rain on the 23rd caused minor flooding along sections of the Schuylkill River. The Schuylkill River at Norristown was above its 13 foot flood stage from 412 a.m. EDT through 1009 a.m. EDT on the 24th. It crested at 13.23 feet at 645 a.m. EDT. Event precipitation totals included 3.25 inches in Pottstown, 1.85 inches in Plymouth Meeting and 1.61 inches in Collegeville.

Flood in DELAWARE, PENNSYLVANIA
From 24-SEP-11 00:04:00 to 24-SEP-11 16:16:00 (EST-5)
Location: FLORIDA PARK
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: River/Stream Gage

The runoff from the heavy rain on the 23rd caused minor flooding on the Crum Creek and Main Stem of the Brandywine Creek on the 24th. The main stem of the Brandywine Creek at Chadds Ford was above its 9 foot flood stage from 342 a.m. EDT through 516 p.m. EDT on the 24th. It crested at 10.91 feet at 1045 a.m. EDT.  The Crum Creek near Newtown Square was above its 6 foot flood stage from 104 a.m. EDT through 202 a.m. EDT on the 24th. It crested at 6.23 feet at 129 a.m. EDT.   Event precipitation totals included 2.35 inches at the Philadelphia International Airport and 1.63 inches in Drexel Hill.

Flood in MONTGOMERY, PENNSYLVANIA
From 23-SEP-11 20:02:00 to 24-SEP-11 03:22:00 (EST-5)
Location: PENNSBURG
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: River/Stream Gage

The runoff from the heavy rain on the 23rd caused minor flooding in the headwaters of the Perkiomen Creek around the Green Lane Reservoir. The Main Stem of the Perkiomen Creek at East Greenville was above its 4.0 foot flood stage from 902 p.m. EDT on the 23rd through 422 a.m. EDT on the 24th. It crested at 6.54 feet at Midnight EDT on the 24th. This was the 5th highest crest on record. The West Branch of the Perkiomen Creek at Hillegass was above its 5.0 foot flood stage from 908 p.m. EDT on the 23rd through 312 a.m. EDT on the 24th. It crested at 5.24 feet at 10 p.m. EDT on the 23rd. Event precipitation totals included 3.25 inches in Pottstown, 2.40 inches in Palm and 2.38 inches in Gilbertsville.