Flash Flooding in New York, August 29, 2002

Name: Flash Flooding in New York, August 29, 2002
Start: 2002-08-29T10:30
End: 2002-08-29T12:09
Location: New York

August 29, 2002 · NWS OKX · 2 events in 2 counties and zones

Where it happened

Every event with a place to put it; 2 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

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The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 2

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.

Rain developed during the day Wednesday, August 28th as a low pressure wave formed along the Mid Atlantic Coast. A 1 to 2 inch rainfall preceded the arrival of areas of very heavy rain as this wave moved north along the New Jersey Coast during Thursday morning, August 29th. With wet antecedent conditions in place, periods of torrential rain resulted in widespread and significant flooding of low lying and poor drainage areas. Many spotters reported street flooding with road closures throughout these areas. In Nassau County, street flooding was reported in Lido Beach, Merrick, and Hicksville. High waters closed the Northern State Parkway at Routes 106 and 107. Storm total rainfall ranged from 3.05 inches in Hicksville to 5.15 inches in South Massapequa.In Western Suffolk County, flooding was reported at the following locations:In Amityville, County Line Road was flooded north of the Sunrise Highway.In Babylon Village, flooding was reported at the intersection of Stowe Ave. and Bulger Street.In Huntington, flooding occurred along New York Avenue (Route 110).In Melville, flooding was reported at the intersection of Sweet Hollow Road and Walt Whitman Road.In Wantagh, flooding was reported on Old Mill Road.In Nesconset, a section of Alexander Ave. and Jericho Turnpike was flooded.In addition, spotters reported street flooding in Saint James.Storm total rainfall in Western Suffolk County ranged from 3.88 inches in Setauket to 5.40 inches in Amityville.

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 29, 9:00 AM EST, 1 hour 30 minutes earlier.

Area forecast discussion, Aug 29, 9:00 AM EST, 1 hour 30 minutes before

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE NEW YORK NY
1000 AM EDT THU AUG 29 2002

RADAR ESTIMATED STORM TOTALS LOOK FAIRLY CLOSE TO ACTUAL OBSERVED
TOTALS. FYI...RADAR ESTIMATES RUNNING ABOUT 1/2 INCH BELOW IN SPOTS.

RADAR LOOPS SHOW A BACK EDGE TO RAIN ACROSS NJ ZONES. WILL WAIT A
LITTLE LONGER TO DETERMINE BEST WORDED FORECAST FOR THIS AFTERNOON.
STILL LOOKS LIKE EASTERN HALF OF FORECAST WILL BE THE PLACES TO SEE
BULK OF QPF THROUGH THE AFTERNOON HOURS.

NEITHER MODEL HAS PICKED UP ON QPF PLACEMENT WITH AVN PROBABLY
CLOSER TO REALITY. ANYWAY...OUTSIDE OF LOCAL URBAN FLOODING
PROBLEMS...RIVERS AND STREAMS SHOULD BE ABLE TO HANDLE THIS PRECIP.

WILL CONTINUE WITH SCA CONDITIONS OUT AHEAD OF THE FRONT INTO EARLY
THIS AFTERNOON...THEN WINDS SUBSIDE WITH APPROACH OF FRONT.

AVN..AS TIME GOES ON TODAY...MAINLY MVFR TYPE CEILINGS AND
VISIBILITIES...EXCEPT IN ANY HEAVIER RAIN.

PW

******3:29 AM DISCUSSION*****

WARM FRONT JUST SOUTH OF THE AREA WITH DEEP MOISTURE LAYER OVER THE
AREA. PRECIPITABLE WATER 1.5 TO 2 INCHES. AVN AND ETA GIVING THE
HIGHEST QPF FOR THE AREA WITH ETA THE MOST...THOUGH DOES LINGER THE
RAIN OVER THE AREA INTO SAT MORNING. WITH THE HIGH BUILDING IN FROM
THE NORTH FRI WL LEAN MORE WITH THE AVN AND START TO TAPER OFF THE
RAIN DURING THE AFTN WITH JUST CHC POPS FRI EVEN. SO LOOKING FOR QPF
IN THE 2 TO 3 INCH RANGE. THIS DOES NOT POSE ANY FLOODING PROBLEMS
WITH DRY CONDITIONS PREVIOUS TO EVENT AND FACT THAT PCPN WL BE OVER
36 TO 48 HOURS. HI INTO THE AREA SAT AND WILL LEAVE DRY
NOW...ALTHOUGH WL KEEP CLDS IN THE AREA. HIGH MOVES OFF SAT NIGHT
WITH ANOTHER FNT APCHG WL KEEP CHC POPS IN SAT NIGHT INTO MON.

MARINE: SCA UP FOR ALL WATERS WITH WINDS 20 TO 25 KT EARLY THEN
DIMINISHING. SEAS WILL BE SLOW TO SUBSIDE AND WILL KEEP 5 FT OR
HIGHER INTO FRI THAN BELOW 5 FT FRI NIGHT. INCREASING EASTERLY FLOW
SAT AND SUN WITH HIGH BUILDING INTO THE AREA SEAS WILL BUILD AGAIN 6
TO 8 FT.

CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SCA FOR ALL WATERS...ANZ355-353-350-338-335-330.

The radar

The Brookhaven radar (KOKX), 62 km away, was scanning. The volume nearest the first event began at 15:32 UTC.

Open the radar archive at this moment

Event by event

2 flash flood. Local standard time, as filed.

Flash Flood, Nassau

When: August 29, 10:30 AM EST to 11:00 AM EST
Where: Nassau County, Lido Beach
Reported by: TRAINED SPOTTER
Coordinates: 40.732, -73.585 (the zone’s center; the record gives no point)

Flash Flood, Suffolk

When: August 29, 11:30 AM EST to 12:09 PM EST
Where: Suffolk County, West Portion
Reported by: TRAINED SPOTTER
Coordinates: 40.941, -72.685 (the zone’s center; the record gives no point)

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

Every storm in New York in 2002 Every state in 2002 This day in weather history Warnings in New York, August 2002

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: 5313170, 5313171.