Flash Flood, Chester
- When
- January 18, 7:30 PM EST to 9:00 PM EST
- Where
- Chester County, East Portion
- Reported by
- AWOS,ASOS,MESONET,ETC
- Coordinates
- 39.973, -75.748 (the zone’s center; the record gives no point)
Flash Flood in Pennsylvania, January 18, 1999
The combination of showers and thunderstorms with heavy rain and the already saturated ground caused flooding along some of the river and streams across the eastern part of Chester County. Pennsylvania State Route 100 at the intersection of Pennsylvania State Route 926 was closed because of flooding along the Brandywine Creek.
Where it happened
Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
- Tornadoes
- Tropical storms and surge
- Floods
- Wind
- Hail
- Winter weather
- Heat and drought
- Cold
- Fire, smoke and dust
- Marine and coastal
- Other
The toll
- Deaths
- 0
- Injuries
- 0
- Property damage
- None recorded
- Crop damage
- None recorded
- Events
- 1
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
What happened
The episode as NWS PHI wrote it up.
The combination of showers and thunderstorms with heavy rain and the already saturated ground caused flooding along some of the river and streams across the eastern part of Chester County. Pennsylvania State Route 100 at the intersection of Pennsylvania State Route 926 was closed because of flooding along the Brandywine Creek. The East Branch of the Brandywine Creek at Downingtown was above its 7 foot flood stage from 730 p.m. through 9 p.m. EST on the 18th. It crested at 7.06 feet at 8 p.m. EST. Storm totals were not very heavy rain, but this came just a couple of days after another heavy precipitation event. Rainfall totals included 1.17 inches in West Chester.
The radar
The Philadelphia radar (KDIX), 114 km away, was scanning. The volume nearest the first event began at 00:27 UTC.
Event by event
1 flash flood. Local standard time, as filed.
What these are
- Flash Flood
- Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
The same day elsewhere
- Avalanche in Washington, January 18, 1999
- Tornado in Pennsylvania, January 18, 1999
- High Wind in New Jersey, January 18 to 19, 1999
- Damaging Winds and Waterspout in Maryland, January 18, 1999
- High Wind in New Jersey, January 18, 1999
- High Wind in Pennsylvania, January 18, 1999
- Tornado in Pennsylvania, January 18, 1999
- Damaging Wind and High Wind in Massachusetts, January 18, 1999
- High Wind in West Virginia, January 18, 1999
- Damaging Wind in New Jersey, January 18, 1999
- Winter Weather in Maine, January 18 to 19, 1999
- Hail in Alabama, January 18, 1999
More
Every storm in Pennsylvania in 1999Every state in 1999This day in weather historyWarnings in Pennsylvania, January 1999
Sources
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-10-01. Each event’s entry at NCEI: 5685300.