Showers and thunderstorms developed, and with little steering flow aloft this caused the storm motion to be slow. The slow storm motion resulted in instances of flooding and flash flooding.

Flash Flood in ANNE ARUNDEL, MARYLAND
From 12-AUG-20 17:10:00 to 12-AUG-20 19:30:00 (EST-5)
Location: GLEN BURNIE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Maryland 648 was flooded and closed at Muddy Bridge Branch near Interstate 97.

Flash Flood in ANNE ARUNDEL, MARYLAND
From 12-AUG-20 17:15:00 to 12-AUG-20 19:30:00 (EST-5)
Location: GARLAND
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Dorsey Road was inundated and impassable near BWI Airport.

Flash Flood in BALTIMORE, MARYLAND
From 12-AUG-20 17:02:00 to 12-AUG-20 19:00:00 (EST-5)
Location: OELLA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

The 21000 Block of Frederick Road was flooded and impassable.

Flash Flood in BALTIMORE, MARYLAND
From 12-AUG-20 17:07:00 to 12-AUG-20 19:00:00 (EST-5)
Location: OELLA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Rapidly flowing water was flowing down Westchester Avenue near Ellicott City on the Baltimore County Side.

Flash Flood in BALTIMORE, MARYLAND
From 12-AUG-20 17:26:00 to 12-AUG-20 19:00:00 (EST-5)
Location: BALTIMORE HIGHLANDS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Hammonds Ferry Road was flooded between Ridge Avenue and Hazel Avenue.

Flash Flood in BALTIMORE, MARYLAND
From 12-AUG-20 17:26:00 to 12-AUG-20 19:00:00 (EST-5)
Location: BELMONT
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

A vehicle was trapped in floodwaters on Dogwood Road at Dogwood Run.

Flash Flood in BALTIMORE, MARYLAND
From 12-AUG-20 17:30:00 to 12-AUG-20 19:00:00 (EST-5)
Location: HALETHORPE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

The water level along the East Branch Herbert Run in Arbutus rapidly rose above flood stage, cresting at 8.35 feet at 5:30 PM EST on August 12th. Water covered yards around Tom Day Boulevard and it approached structures along the creek.

Flash Flood in HOWARD, MARYLAND
From 12-AUG-20 17:50:00 to 12-AUG-20 18:42:00 (EST-5)
Location: ELLICOTT CITY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: River/Stream Gage

The water level rapidly rose above flood stage along the Patapsco River at Elkridge. The water level crested at 16.2 feet at 6:15 PM EST on the 12th of August. Water covered a portion of River Road in the Patapsco Valley State Park. A large portion of the park was also flooded near the playground off Gunn Road.

Flash Flood in HOWARD, MARYLAND
From 12-AUG-20 17:54:00 to 12-AUG-20 19:29:00 (EST-5)
Location: ELKRIDGE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: River/Stream Gage

The water level rapidly rose above flood stage along the Patapsco River at Elkridge (ELKM2). The water level crested at 18.7 feet at 6:30 PM EST on the 12th of August. Hammonds Ferry Road was flooded and backwater flooding also led to the closure of Furnace Avenue in Elkridge.
The water level remained above flood stage until 10:24 PM EST on August 12th.

Flood in MONTGOMERY, MARYLAND
From 12-AUG-20 17:12:00 to 12-AUG-20 19:12:00 (EST-5)
Location: LUXMANOR
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Six inches of water over roadway near intersection of Old Georgetown Rd. and Rockville Pike.

Flood in BALTIMORE, MARYLAND
From 12-AUG-20 17:50:00 to 12-AUG-20 19:50:00 (EST-5)
Location: SPARROWS PT
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Floodwaters up over the hoods of some parked cars near West St. and Leadenhall St.

Flood in FREDERICK, MARYLAND
From 12-AUG-20 18:15:00 to 12-AUG-20 20:15:00 (EST-5)
Location: FREDERICK
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Multiple reports of flooded roads in the southern portions of Frederick City.

Flood in ALLEGANY, MARYLAND
From 12-AUG-20 21:04:00 to 12-AUG-20 23:04:00 (EST-5)
Location: EVITTS CREEK
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

About a foot of flowing water over the intersection at E Oldtown Rd. and Blackston Ave.

Flood in BALTIMORE, MARYLAND
From 12-AUG-20 17:04:00 to 12-AUG-20 19:04:00 (EST-5)
Location: BELMONT
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Vehicle in flood waters near the intersection of Baltimore National Pike and North Rolling Rd.

Flood in BALTIMORE, MARYLAND
From 12-AUG-20 17:06:00 to 12-AUG-20 19:06:00 (EST-5)
Location: SPARROWS PT
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Urban/Poor Drainage Flooding in Federal Hill.

Flood in BALTIMORE, MARYLAND
From 12-AUG-20 17:29:00 to 12-AUG-20 19:29:00 (EST-5)
Location: BALTIMORE HIGHLANDS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Vehicle in flood water near the intersection of Myrtle Ave. and Tulip Ave.