Flood — Montgomery, Pennsylvania
2010-10-01 · near Stowe, Montgomery, Pennsylvania
Event narrative
The Perkiomen Valley was hit the hardest by flooding in Montgomery County. A 55-year-old woman drowned after she drove into flood waters of the Skippack Creek on the morning of October 1st off Stump Hall road just north of Anders Road near Evansburg State Park near Skippack. Near Schwenksville, two men were swept into the East Branch of the Perkiomen Creek as they tried to drive over the Park Avenue Bridge. They were rescued from the creek about eight hours later. The sewage treatment plant was flooded in Schwenksville. In Collegeville, there were eight rescues. Homes along the Skippack Pike near the Skippack Creek were flooded. In Lower Salford Township, a vehicle rescue occurred near the intersection of Quarry and Store Roads. Several roads were closed in Towamencin Township, many along the Skippack Creek. An ambulance became stuck on the bridge over the Skippack Creek on Old Forty Foot Road. In Teleford, there were five rescues. Along the Schuylkill River, Riverfront Park flooded in Pottstown and two homeless people were rescued. In West Norriton, about 200 people were evacuated from the Jefferson Villa Apartment after its basement flooded with Schuylkill River water. The King of Prussia Mall flooded and forced the closure of one store and the food court. In all one home was destroyed and another suffered major damage. One business suffered major flood damage. There was moderate damage at the King of Prussia mall complex in the food court area and ninety-three other homes suffered minor damage. Two bridges, three parks, eight roadways and three sewer treatment facilities suffered minor damage.
The Schuylkill River at Norristown was above its 17 foot flood stage from 803 a.m. EDT through 306 p.m. EDT on the 1st. It crested at 18.31 feet at1030 a.m. EDT. The East Branch of the Perkiomen Creek at Schwenksville had major flooding, tied for the fourth highest crest on record and the highest crest since June of 2006. The creek was above its 7 foot flood stage from 141 a.m. EDT through 209 p.m. EDT on the 1st. It crested at 12.18 feet at 10 a.m. EDT. The Main Stem of the Perkiomen Creek at East Greenville was above its 4 foot flood stage from 233 a.m. EDT through 1040 a.m. EDT on the 1st. It crested at 6.02 feet at 7 a.m. EDT. Farther downstream, the main stem of the Perkiomen Creek at Graterford had moderate flooding. It was the highest crest since October of 2005. The creek was above its 11 foot flood stage from 152 a.m. EDT through 252 p.m. EDT on the 1st. It crested at 14.86 feet at 615 a.m. EDT. The Wissahickon Creek at Fort Washington was above its 9 foot flood stage from 3 a.m. EDT through 1116 a.m. EDT on the 1st. It crested at 12.82 feet at 715 a.m. EDT.
Event precipitation totals included 10.55 inches in Graterford, 9.39 inches in Pennsburg, 9.36 inches in Collegeville, 7.40 inches in Conshohocken and 6.55 inches in Pottstown.
Wider weather episode
A series of low pressure systems that moved north along a slowly moving cold front brought heavy rain into Eastern Pennsylvania on September 30th and October 1st. Event precipitation totals average 5 to 10 inches with the highest amounts in the Philadelphia western suburbs. Many streams and rivers flooded, but the worst flooding occurred in Delaware, Chester, Montgomery and Philadelphia Counties where waterways crested at moderate to major levels. For many gaged waterways, it was the worst flooding since June of 2006. Around Delaware County it was described as the worst flooding since Hurricane Floyd in 1999. The first round of heavy rain occurred during the early morning of September 30th, but extremely dry antecedent soil conditions were able to absorb most of the heavy rain and mainly just poor drainage flooding occurred. The second and heavier round of precipitation moved in during the evening of September 30th and continued into the morning of October 1st. The rain ended during the morning of October 1st.
A low pressure system formed along a stationary front off the Carolina Coast during the night of September 29th. At 8 a.m. EDT on September 30th, it moved into central North Carolina and continued to move north. The low slowly weakened as it moved north and reached Pennsylvania on the evening of September 30th. Another low pressure system formed off the Carolina coast during the late morning of September 30th. This low was able to ingest tropical moisture associated with dissipating Tropical Storm Nicole. At 8 p.m. EDT on the 30th, the low pressure system moved north into eastern North Carolina and at 2 a.m. EDT on October 1st, it moved into the Delmarva Peninsula. At 8 a.m. EDT on October 1st, the low pressure system was just east of Atlantic City on its way to passing through eastern Long Island during the afternoon of October 1st.
View location on OpenStreetMap → (40.2442, -75.6817)
Source: NOAA Storm Events Database, event_id 265678. Narrative written by the NWS forecast office that issued the report.