A weak disturbance just north of a stalled stationary boundary provided a focusing mechanism for heavy rainfall that resulted in isolated flash flooding across parts of Long Island. In an environment with precipitable water values around two inches, rainfall amounts ranged from 1-3 across much of Nassau and Suffolk counties. In Suffolk County, a CWOP station reported 2.79 of rain in Mastic Beach, while in Nassau County a 2.15 of rain was reported in North Bellmore via social media.

Flash Flood in SUFFOLK, NEW YORK
From 12-AUG-18 05:58:00 to 12-AUG-18 06:30:00 (EST-5)
Location: MORICHES
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

A basement on Frowein Road in Center Moriches was flooded.

Flash Flood in SUFFOLK, NEW YORK
From 12-AUG-18 06:00:00 to 12-AUG-18 06:30:00 (EST-5)
Location: QUIOGUE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

A basement was flooded on Main Street in Westhampton Beach due to heavy rain.

Flash Flood in NASSAU, NEW YORK
From 12-AUG-18 11:46:00 to 12-AUG-18 13:07:00 (EST-5)
Location: NORTH BELLMORE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

People were trapped in cars at the intersection of Bellmore Avenue and Decatur Avenue in Bellmore due to flooding.

Flash Flood in NASSAU, NEW YORK
From 12-AUG-18 11:57:00 to 12-AUG-18 13:07:00 (EST-5)
Location: NORTH BELLMORE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

People were trapped in cars at the intersection of Shaw Drive and Jerusalem Avenue in North Merrick due to flooding.

Flash Flood in NASSAU, NEW YORK
From 12-AUG-18 11:58:00 to 12-AUG-18 13:07:00 (EST-5)
Location: NORTH BELLMORE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

People were trapped in cars at the intersection of North Jerusalem Road and Ennabrock Road in East Meadow due to flooding.

Flash Flood in NASSAU, NEW YORK
From 12-AUG-18 12:00:00 to 12-AUG-18 13:07:00 (EST-5)
Location: BALDWIN
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Intersections in the village of Rockville Center were under moving water.

Flash Flood in NASSAU, NEW YORK
From 12-AUG-18 12:20:00 to 12-AUG-18 13:07:00 (EST-5)
Location: NORTH BELLMORE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Major flooding was reported on many streets in North Bellmore after 2.05 inches of rain in 40 minutes. The fire department was responding to multiple rescues from vehicles.

Flash Flood in NASSAU, NEW YORK
From 12-AUG-18 12:37:00 to 12-AUG-18 13:07:00 (EST-5)
Location: NORTH BELLMORE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

North Jerusalem Avenue was flooded with 8-10 inches of standing water in East Meadow.

Flash Flood in SUFFOLK, NEW YORK
From 12-AUG-18 06:00:00 to 12-AUG-18 06:30:00 (EST-5)
Location: SHIRLEY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Monroe Drive in Mastic Beach was impassable due to flooding.