Flash Flood, Montgomery
- When
- July 23, 1:00 PM EST
- Where
- Montgomery County, Amsterdam
- Property damage
- $2,000
- Reported by
- TRAINED SPOTTER
- Coordinates
- 42.902, -74.440 (the zone’s center; the record gives no point)
Flash Flood and Damaging Winds in New York, July 23, 1999
Scattered thunderstorms developed in an unstable air mass during the afternoon of July 23 in the Mohawk Valley. Both of the thunderstorms cells become severe.
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
- $5,000
- Crop damage
- None recorded
- Events
- 3
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 ALY wrote it up.
Scattered thunderstorms developed in an unstable air mass during the afternoon of July 23 in the Mohawk Valley. Both of the thunderstorms cells become severe. One produced wind gusts strong enough to down trees at Fort Johnson, the other in Amsterdam. In addition, torrential rains spawned flooding on a few of the streets in Amsterdam.
The radar
The Albany radar (KENX), 47 km away, was scanning. The volume nearest the first event began at 18:08 UTC.
Event by event
2 thunderstorm wind, 1 flash flood. Local standard time, as filed.
Thunderstorm Wind, Montgomery
- When
- July 23, 1:07 PM EST
- Where
- Montgomery County, Amsterdam
- Property damage
- $1,000
- Reported by
- TRAINED SPOTTER
- Coordinates
- 42.930, -74.180
Thunderstorm Wind, Montgomery
- When
- July 23, 1:40 PM EST
- Where
- Montgomery County, Ft Johnson
- Property damage
- $2,000
- Reported by
- TRAINED SPOTTER
- Coordinates
- 42.950, -74.220
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.
- Thunderstorm Wind
- Winds from a thunderstorm of 50 knots (58 mph) or more, or lower winds that caused damage or casualties. Measured gusts are marked MG, estimated EG.
After NWS Directive 10-1605, the rules offices file Storm Data by.
The same day elsewhere
- Heat in Missouri, July 23 to 31, 1999
- Heat in Pennsylvania, July 23 to 31, 1999
- Heat in Wisconsin, July 23 to 31, 1999
- Hail and Damaging Winds in Michigan, July 23, 1999
- Heat in Minnesota, July 23 to 25, 1999
- Heat in Maryland, July 23 to 31, 1999
- Heat in South Carolina, July 23, 1999
- Heat in Arkansas, July 23, 1999
- Heat in Delaware, July 23 to 31, 1999
- Hail and Damaging Winds in Wisconsin, July 23, 1999
- Tornadoes and Hail in Michigan, July 23, 1999
- Hail and Damaging Winds in Ohio, July 23, 1999
More
Every storm in New York in 1999Every state in 1999This day in weather historyWarnings in New York, July 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: 5707239, 5707237, 5707238.