New York, 2001

Flooding and Lightning Strike in New York, August 20, 2001

August 20, 2001 · NWS OKX · 3 events in 2 counties and zones

On Monday, August 20th, a low pressure system located over the eastern Great Lakes moved east across northern New England. A cold front attached to this low moved east across southeast New York during the afternoon hours, preceded and accompanied by scattered strong thunderstorms.

Where it happened

Every event with a place to put it; 3 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

Open the live radar over this ground

The toll

Deaths
0
Injuries
0
Property damage
$65,000
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 OKX wrote it up.

On Monday, August 20th, a low pressure system located over the eastern Great Lakes moved east across northern New England. A cold front attached to this low moved east across southeast New York during the afternoon hours, preceded and accompanied by scattered strong thunderstorms. These thunderstorms were accompanied by frequent cloud to ground lightning and heavy rainfall.In Mount Vernon, a house on Greendale Avenue sustained severe damage when lightning struck the roof around 2:20 PM EDT, and the resultant fire spread to the second floor. Three children were in the house, but escaped unharmed. Estimated damage to the house was in the range of 60 to 70 thousand dollars. The roof of a condominium in Lewisboro on Deer Hill was struck shortly before 2 PM EDT. No injuries were reported, and the resultant fire and damage was minor to moderate. Heavy rainfall also accompanied these thunderstorms, which led to localized flooding of roadways and highways. Two to three inches of rain were reported in the vicinity of White Plains, inducing minor to moderate flooding of Route 125, and also in some homes. Up to 3 feet of water pooled along Lamont Street near Nepperhan Avenue in Elmsford. In Putnam County, a driver was stranded in a pool of water on Route 6 when the car stalled. The driver waded to higher ground, and escaped uninjured.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS New York, NY wrote its last area forecast discussion before the first event at Aug 20, 9:20 AM EST, 3 hours 10 minutes earlier.

Area forecast discussion, Aug 20, 9:20 AM EST, 3 hours 10 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
1020 AM EDT MON AUG 20 2001

DISC...WILL HAVE TO MAKE A FEW CHANGES TO THE PREV FCST. FOR THE
START SPC HAS PUT US IN THE SLIGHT RISK FOR TSTM ACTIVITY FOR THIS
AFTN. LOOKING AT THE MRNG SOUNDINGS WE BEGIN THE DAY A BIT UNSTABLE
AND WITH THE WRM FNT JUST TO OUR S AND SOME SHWRS ALREADY BREAKING
OUT AND MOVING TO THE N. AS THE FNT MOVS TO THE N AND THE SLOW MOVNG
CDFNT/TROF APPROACHES FM THE W WE WILL DESTABLIZE A BIT MORE AHND
THE THREAT OF SHWRS/TSTMS WILL BECOME A GREATER RISK.

THERE IS SOME DRYING AT THE H7 LVL AND THIS MAY HELP KP THE THREAT
OF HVY SHWRS DOWN SOME...BUT AS WE DO BECOME A MORE UNSTABLE AND THE
MOIST WORKS ITS WAY INTO OUR RGN WE CUD GET SOME GUSTY WINDS AND HVY
RAINFALL.

SOUNDINGS OUT OF ALB AND BUF SHOW THE MOIST IS UP TO THE H7 LVL AND
THIS WILL WORK INTO OUR RGN BY THE AFTN HRS. ETA BUFKIT SHWS THAT
THERE ARE 30 TO 40 KT WINDS UP INTO THE LWR LVLS AND THIS TOO CUD
GET DOWN WITH THE SHWR ACTIVITY. EARLY MRNG CLDS ARE BEGINNING TO
BREAK UP AND THE SUN IS STRTNG TO APPEAR AND THIS WILL ONLY ENHANCE
US TO DESTABILIZE. THETA RIDGE MOVS IN BY 00Z AND THE ETA MODEL
SHOWS THE RIDGE IS OVR US ARND THEN.

.OKX...
CT...NONE.
NJ...NONE.
NY...NONE.
MARINE...NONE.

The radar

The Brookhaven radar (KOKX), 97 km away, was scanning. The volume nearest the first event began at 17:30 UTC.

Open the radar archive at this moment

Event by event

2 flood, 1 lightning. Local standard time, as filed.

Flood, Putnam

When
August 20, 12:30 PM EST
Where
Putnam County, Brewster
Reported by
NEWSPAPER
Coordinates
41.427, -73.749 (the zone’s center; the record gives no point)

Lightning, Westchester

When
August 20, 1:20 PM EST
Where
Westchester County, Mt Vernon
Property damage
$65,000
Reported by
NEWSPAPER
Coordinates
41.152, -73.753 (the zone’s center; the record gives no point)

Flood, Westchester

When
August 20, 1:39 PM EST
Where
Westchester County, White Plains
Reported by
TRAINED SPOTTER
Coordinates
41.152, -73.753 (the zone’s center; the record gives no point)

What these are

Flood
Flooding that develops more slowly than a flash flood: rivers leaving their banks, or water standing over land for an extended time.
Lightning
A lightning strike that killed, injured or caused damage.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

More

Every storm in New York in 2001Every state in 2001This day in weather historyWarnings in New York, August 2001

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: 5265249, 5265178, 5265248.