A hot and very moist air mass was in place across the region with dewpoints in the 70s and precipitable water values approaching 2 inches. Diurnal instability along a lake breeze boundary allowed for convection to develop. The most notable thing about these boundaries was the intersection of the boundary off of Lake Erie with a weaker one south of Lake Ontario. Thunderstorms developed and trained along this intersection for hours. The net result was some of the heaviest rains our area has ever seen in such a short duration with amounts of between 7 and 8 inches reported in Orleans County.

Heavy Rain in NIAGARA, NEW YORK
From 27-JUL-20 12:43:00 to 27-JUL-20 12:43:00 (EST-5)
Location: HARTLAND
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Rainfall of 2.03 inches fell in less than 90 minutes.

Heavy Rain in ORLEANS, NEW YORK
From 27-JUL-20 13:50:00 to 27-JUL-20 13:50:00 (EST-5)
Location: MEDINA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Rainfall of 2.82 inches fell between noon and 2:50 PM.

Heavy Rain in ORLEANS, NEW YORK
From 27-JUL-20 13:57:00 to 27-JUL-20 13:57:00 (EST-5)
Location: KNOWLESVILLE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Rainfall of 2.16 inches was reported in less than three hours.

Heavy Rain in ORLEANS, NEW YORK
From 27-JUL-20 14:00:00 to 27-JUL-20 14:00:00 (EST-5)
Location: GAINES BASIN
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Rainfall of 3.75 inches was reported.

Heavy Rain in ORLEANS, NEW YORK
From 27-JUL-20 15:00:00 to 27-JUL-20 15:00:00 (EST-5)
Location: MEDINA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Rainfall of 5.59 inches reported.

Heavy Rain in ORLEANS, NEW YORK
From 27-JUL-20 15:00:00 to 27-JUL-20 15:00:00 (EST-5)
Location: KNOWLESVILLE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Total rainfall of 4.21 inches reported with 3.45 inches since 2:20 PM.

Heavy Rain in ORLEANS, NEW YORK
From 27-JUL-20 15:00:00 to 27-JUL-20 15:00:00 (EST-5)
Location: GAINES BASIN
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Rainfall of 5.10 inches fell in 3.5 hours.

Heavy Rain in ORLEANS, NEW YORK
From 27-JUL-20 19:10:00 to 27-JUL-20 19:10:00 (EST-5)
Location: KNOWLESVILLE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Rainfall of 5.27 inches reported.

Heavy Rain in ORLEANS, NEW YORK
From 27-JUL-20 21:24:00 to 27-JUL-20 21:24:00 (EST-5)
Location: MEDINA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Rainfall of 7.03 inches report.

Flash Flood in ORLEANS, NEW YORK
From 27-JUL-20 15:00:00 to 27-JUL-20 18:00:00 (EST-5)
Location: GAINES BASIN
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Ditches were overflowing and running across roads. In 3.5 hours, 5.10 inches of rainfall was reported.

Flash Flood in NIAGARA, NEW YORK
From 27-JUL-20 16:00:00 to 27-JUL-20 18:00:00 (EST-5)
Location: MIDDLEPORT
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Widespread flash flooding was reported in Middleport, including on Main, Vernon, and State streets.

Flash Flood in ORLEANS, NEW YORK
From 27-JUL-20 16:00:00 to 27-JUL-20 18:00:00 (EST-5)
Location: FIVE CORNERS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Flash flooding from Oak Orchard Estates that closed Bacon Rd to Medina. A travel ban was instituted for Medina due to impassable roads.

Flash Flood in ORLEANS, NEW YORK
From 27-JUL-20 17:00:00 to 27-JUL-20 18:00:00 (EST-5)
Location: KNOWLESVILLE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Portage Road was closed due to flooding.

Flash Flood in ORLEANS, NEW YORK
From 27-JUL-20 17:45:00 to 27-JUL-20 18:00:00 (EST-5)
Location: MEDINA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Additional flooding was reported in Medina.