Showers producing very heavy rain moved very slowly very slowly across South Central Maryland during the afternoon. The deluge caused several streets and creeks to become rapidly flowing rivers.
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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.
The episode as NWS LWX wrote it up.
Showers producing very heavy rain moved very slowly very slowly across South Central Maryland during the afternoon. The deluge caused several streets and creeks to become rapidly flowing rivers. Rainfall totals in Charles County ranged from around 2.0 inches on the west side of Waldorf to 5.7 inches about 5 miles east of town. Several portions of Action Lane near the Mattawoman Creek were closed due to high water. The Lynnbrook subdivision in Waldorf had several homes surrounded and flooded by water, and some residents had to be rescued by firefighters. Over $100,000 damage was reported in the neighborhood. Hamilton Drive had water flowing over it like a waterfall. One car caught in the rapidly rising water was submerged up its windows. A work vehicle valued over $40,000 was totalled after being overcome by quickly rising water up to the steering wheel. Near the intersection of Acton Lane and Highway 301 in Waldorf, water became so deep a hotel had to be evacuated. The northern and central portions of St. Mary's County also reported flooding. Morganza reported a rainfall total of 5.13 inches, Leonardtown received 7.7 inches, Hollywood received up to 7.2 inches, Tall Timbers received 2.45 inches, and Scotland in the extreme southern part of the county reported 1.7 inches. Several creeks and small streams were out of their banks, and roads in low lying areas were covered by water. An earth wall along Washington Street in Leonardtown collapsed and the water level of Town Run rose 8 feet. Nearly 20 county roads were covered by 4 to 6 inches of water and debris. Route 243 was blocked by floodwaters. Limbs and other debris were washed into the Highway 5 and Route 4 intersection. County road crews were out until the following morning clearing debris and making repairs. Trees were also downed across Millstone Landing Road in California and Joy Chapel Road in Hollywood. Rainfall amounts over 3 inches were common in Prince Georges County as well, temporarily flooding some city streets and creeks. Wet pavement was a contributing factor in a fatal accident near Brandywine. A 16 year old girl was killed when her car went out of control and collided with two other cars.
The national radar mosaic for the moment the first event began.
2 flash flood, 1 heavy rain. Local standard time, as filed.
Several streets flooded, homes damaged by flood waters, residents in low lying areas evacuated
20 roads flooded, earth retaining wall destroyed, basements flooded, trees downed
Over 3 inches of rain in many areas
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Maryland in 1999Every state in 1999This day in weather historyWarnings in Maryland, August 1999
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: 5718988, 5718989, 5718990.