Rich tropical moisture streamed northward up the eastern seaboard, while a shortwave trough pivoted across the Mid-Atlantic as it rotated around a stationary closed upper low pressure over the Great Lakes.  A band of moderate to heavy rain set up across much of Maryland, and flood and flash flooding occurred across portions of northern Maryland.  Rainfall totals reached as high as 4.48 inches in Baltimore County.

Flash Flood in FREDERICK, MARYLAND
From 23-SEP-11 10:22:00 to 23-SEP-11 12:00:00 (EST-5)
Location: ST ANTHONY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

A portion of Route 76 is flooded and closed near Route 15 just south of Mount Saint Mary's College.  A nearby spotter observed 2.00 inches of rain.

Flash Flood in FREDERICK, MARYLAND
From 23-SEP-11 10:39:00 to 23-SEP-11 12:00:00 (EST-5)
Location: LOYS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Route 77 was flooded and closed near Owens Creek.  A nearby spotter recorded 1.16 inches.

Flash Flood in FREDERICK, MARYLAND
From 23-SEP-11 10:39:00 to 23-SEP-11 12:00:00 (EST-5)
Location: CREAGERSTOWN
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Route 550 was flooded and closed near Creagerstown.  A nearby spotter observed 1.31 inches.

Flash Flood in FREDERICK, MARYLAND
From 23-SEP-11 11:15:00 to 23-SEP-11 12:30:00 (EST-5)
Location: EMMITSBURG
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Seton Avenue was flooded and closed in Emmitsburg.  A nearby rain gauge recorded 1.10 inches.

Flash Flood in FREDERICK, MARYLAND
From 23-SEP-11 11:27:00 to 23-SEP-11 12:30:00 (EST-5)
Location: NEW MIDWAY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Northbound Woodsboro Pike was flooded and closed near New Midway.

Flash Flood in BALTIMORE, MARYLAND
From 23-SEP-11 14:50:00 to 23-SEP-11 16:30:00 (EST-5)
Location: LINHIGH
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Route 1 was flooded and closed at Ridgely's Choice Drive.  A nearby observed recorded 4.13 inches.

Flash Flood in BALTIMORE, MARYLAND
From 23-SEP-11 14:53:00 to 23-SEP-11 16:30:00 (EST-5)
Location: GLEN ARM
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Route 147 was flooded and closed near Cowen Run north of Notch Cliff.  An observed nearby measured a total of 2.92 inches.

Flash Flood in ANNE ARUNDEL, MARYLAND
From 23-SEP-11 15:13:00 to 23-SEP-11 16:30:00 (EST-5)
Location: GLEN BURNIE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Route 176 was closed at Route 648 at Sawmill Creek due to flash flooding.  A nearby spotter measured 3.57 inches of rain.

Flood in FREDERICK, MARYLAND
From 23-SEP-11 13:00:00 to 23-SEP-11 18:00:00 (EST-5)
Location: EMMITSBURG
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Roads remain closed in Emmitsburg due to flooding.

Flash Flood in BALTIMORE, MARYLAND
From 23-SEP-11 15:38:00 to 23-SEP-11 16:30:00 (EST-5)
Location: FRANKLINVILLE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Route 1 was closed north of New Cut Road due to flash flooding on Little Gunpowder Falls.  A nearby spotter observed 2.80 inches of rain.