Flash Flood, Somerset
- When
- April 1, 6:30 PM EST to April 2, 8:00 PM EST
- Where
- Somerset County, Countywide
- Coordinates
- 40.564, -74.616 (the zone’s center; the record gives no point)
Flash Flood in New Jersey, April 1 to 2, 1998
A series of thunderstorms with heavy rain moved across Somerset County during the late afternoon and evening of the 1st and caused flooding of streams and creeks as well as considerable urban and poor drainage flooding, especially in the eastern half of the county. The heavy rain and runoff also caused the Millstone River to flood on the 2nd.
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.
A series of thunderstorms with heavy rain moved across Somerset County during the late afternoon and evening of the 1st and caused flooding of streams and creeks as well as considerable urban and poor drainage flooding, especially in the eastern half of the county. The heavy rain and runoff also caused the Millstone River to flood on the 2nd. The first wave of thunderstorms dropped around an inch and a half of rain during the early evening commute. This forced the closure of New Jersey State Route 22 from Greenbrook to North Plainfield. Vehicles were floating in the water in Greenbrook. The second wave of thunderstorms exacerbated conditions and forced the closure of six roadways in Franklin Township. Storm totals in the county approached three inches and included 2.95 inches in Blackwells Mills and 2.88 inches in Belle Mead. The Millstone River in Blackwells Mills went above its 9 foot flood stage at 730 a.m. EST on the 2nd. It crested at 9.42 feet at 215 p.m. EST and was back within bankfull at 8 p.m. EST. No serious injuries or property damage were reported.
The radar
The Philadelphia radar (KDIX), 71 km away, was scanning. The volume nearest the first event began at 23:28 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
- Tornadoes and Hail in Virginia, April 1, 1998
- Tornadoes in North Carolina, April 1, 1998
- Flood in California, April 1, 1998
- Flash Flooding in New Hampshire, April 1, 1998
- Flood in Florida, April 1 to 19, 1998
- Flood in New York, April 1 to 7, 1998
- Tornado in Pennsylvania, April 1, 1998
- Hail and Damaging Winds in Maryland, April 1, 1998
- Flood in Florida, April 1, 1998
- Damaging Wind and Lightning Strike in Pennsylvania, April 1, 1998
- Flooding in Vermont, April 1 to 13, 1998
- Wildfire and Drought in Guam, April 1 to 30, 1998
More
Every storm in New Jersey in 1998Every state in 1998This day in weather historyWarnings in New Jersey, April 1998
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 2026-09-24. Each event’s entry at NCEI: 5643441.