A deep low pressure system moved from the Tennessee Valley to the eastern great Lakes on November 16, sweeping a strong cold front across the Mid Atlantic. This system brought widespread moderate to heavy rain to the region after sunrise, then strong thunderstorms during the early afternoon. These thunderstorms produced periods of heavier rainfall as well as gusty and isolated damaging winds. Although rain ended across the region during the mid afternoon hours, some locations continued to experience flooding until just after midnight.
Heavy rain across Anne Arundel County closed numerous roadways from the early afternoon until after midnight on November 17th. Some of these roads include Governor Bridge Road and Saint George Barber, Routes 10 and 648 (Baltimore-Annapolis Blvd.) and Burns Crossing Road at Severn Run in the town of Severn. Maryland Route 176 (Dorsey Road) and 648 (Baltimore-Annapolis Blvd) continued to be submerged in about two feet of water until after midnight.
Flash Flooding was reported in Baltimore County and the City of Baltimore. Gunpowder River rose out of its banks, allowing water to flow over the bridge at Second Mine Road.  Flash flooding was also reported at Hydes Road and Long Green Pike as well as near White Hall and Gunpowder Falls State Park.  Numerous roads were closed across Baltimore County, including a portion of Pulaski Highway (Route 40).  Several roads in the City of Baltimore were also closed due to flash flooding.  Jones Falls flooded the bridge at Interstate 83 and 41st Street. Other roadways affected by flash flooding include Erdman Avenue on the east side of the city and Caroline and Fleet Streets near downtown.
In Carroll County, water up to 2 feet deep across Twin Arch Road.  An elderly woman became trapped in her car in Sykesville on River Road on the Howard/Carroll County line where the South branch of the Patapsco River rose our of its banks. The South Branch of the Patapsco River also rose out of it's banks onto Old Frederick Road, about 5 miles west of Woodbine.  Route 32 was closed due to flooding near Sykesville.  Numerous roads closed due to flooding near Keymar.
Numerous roads were closed across Charles County, especially near La Plata, Port Tobacco, Bryans Road and Waldorf. One roadway closed due to flooding include Billingsley Road between White Plains and Bryans Roads. Buses were forced to return students to school due to flooded roadways.
In Harford County, Deer Creek was out of its banks near Norrisville, causing localized flooding of some subdivision.  High water on was reported on roads near Bel Air, with several water rescues of stranded motorists.  Two water rescues were conducted near the intersection of Walters Mill and Ady Roads near Bel Air.
Thunderstorms brought damaging winds to Montgomery County between 1:00 PM and 2:00 PM, downing trees and power lines in Woodhaven, Gaithersburg, Layhill, Silver Spring and Bowie. A tree was downed on the Penn Line by a thunderstorm in Bowie. Heavy rain with these thunderstorms produced flooding that continued through early evening across Montgomery County. The Northwest Branch rose out of its banks at Route 29.  Water covered Old Georgetown Road and Battery Lane near Huntington, MD.  More than a dozen water rescues occurred across the county when people became trapped in their cars when trying to cross a flooded roadway. One such rescue was conducted in Germantown along Game Preserve Road.
In Prince George���s County, Routes 301 and 5 were flooded.  Several roads were closed near Andrews Air Force Base due to flooding, including a section of the Interstate 495 Capital Beltway.  A farm equipment store was inundated by water in Upper Marlboro, MD.
In St. Mary���s County, Route 235 and Saint John Road flooded in St. Mary���s City, MD.
Tidal flooding occurred during the afternoon and early evening around the time of high tide in Baltimore.  Strong onshore winds occurred due to a coastal low pressure system.  Flooding of tidal areas and along the shoreline occurred in several communities, including Bowley Bar, Bowley Quarters, Millers Island and near Middle River.  Twelve to 18 inches of water was reported to cover roadways in Millers Island and near Bowleys Quarters. Water approached some houses during high tide.  There was also some coastal flooding at the Harborplace shopping facilities located at the Baltimore Inner Harbor.

Thunderstorm Wind in MONTGOMERY, MARYLAND
From 16-NOV-06 13:10:00 to 16-NOV-06 13:15:00 (EST-5)
Location: GAITHERSBURG
Magnitude: 50.00 EG
Property damage: 22.00K
Crop damage: 0.00K
Reported by: County Official

Thunderstorm winds brought trees down in Gaithersburg and also in the southwest corner of the county near the banks of the Potomac River.

Flash Flood in BALTIMORE CITY (C), MARYLAND
From 16-NOV-06 16:00:00 to 16-NOV-06 19:30:00 (EST-5)
Location: BALTIMORE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Several roads in the City of Baltimore were closed due to flash flooding.  Jones Falls flooded the bridge at Interstate 83 and 41st Street. Other roadways affected by flash flooding include Erdman Avenue on the east side of the city and Caroline and Fleet Streets near downtown.

Flood in ANNE ARUNDEL, MARYLAND
From 16-NOV-06 14:30:00 to 17-NOV-06 01:30:00 (EST-5)
Location: SEVERN
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Heavy rain across Anne Arundel County closed numerous roadways from the early afternoon until after midnight on November 17th. Some of these roads include Governor Bridge Road and Saint George Barber, Routes 10 and 648 (Baltimore-Annapolis Blvd.) and Burns Crossing Road at Severn Run in the town of Severn. Maryland Route 176 (Dorsey Road) and 648 (Baltimore-Annapolis Blvd) continued to be submerged in about two feet of water until after midnight.

Flood in MONTGOMERY, MARYLAND
From 16-NOV-06 13:15:00 to 17-NOV-06 00:15:00 (EST-5)
Location: GERMANTOWN
Flood cause: Heavy Rain
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Newspaper

The Northwest Branch rose out of its banks at Route 29.  Water covered Old Georgetown Road and Battery Lane near Huntington, MD.  More than a dozen water rescues occurred across the county when people became trapped in their cars when trying to cross a flooded roadway. One such rescue was conducted in Germantown along Game Preserve Road.

Flood in BALTIMORE, MARYLAND
From 16-NOV-06 19:30:00 to 17-NOV-06 00:30:00 (EST-5)
Location: COCKEYSVILLE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Roads were closed due to high water in the Cockeysville area.

Coastal Flood in SOUTHERN BALTIMORE, MARYLAND
From 16-NOV-06 15:00:00 to 16-NOV-06 17:00:00 (EST-5)
Property damage: 15.00K
Crop damage: 0.00K
Reported by: County Official

Tidal flooding occurred during the afternoon and early evening around the time of high tide.  Strong onshore winds occurred due to a coastal low pressure system.  Flooding of tidal areas and along the shoreline occurred in several communities, including Bowley Bar, Bowley Quarters, Millers Island, and near Middle River.  Twelve to 18 inches of water was reported to cover roadways in Millers Island and near Bowleys Quarters. Water approached some houses during high tide.  There was also some coastal flooding at the Harborplace shopping facilities located at the Baltimore Inner Harbor.

Thunderstorm Wind in MONTGOMERY, MARYLAND
From 16-NOV-06 13:10:00 to 16-NOV-06 13:15:00 (EST-5)
Location: SILVER SPG
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Newspaper

Thunderstorm winds brought trees down in Silver Spring, MD.

Thunderstorm Wind in PRINCE GEORGE'S, MARYLAND
From 16-NOV-06 13:30:00 to 16-NOV-06 13:30:00 (EST-5)
Location: BOWIE
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Newspaper

A tree was downed on the Penn Line by a thunderstorm in Bowie.

Flood in CHARLES, MARYLAND
From 16-NOV-06 16:15:00 to 16-NOV-06 18:15:00 (EST-5)
Location: LA PLATA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Numerous roads were closed across Charles County, especially near La Plata, Port Tobacco, Bryans Road and Waldorf. One roadway closed due to flooding include Billingsley Road between White Plains and Bryans Roads. Buses were forced to return students to school due to flooded roadways.

Flood in HARFORD, MARYLAND
From 16-NOV-06 17:00:00 to 16-NOV-06 22:30:00 (EST-5)
Location: NORRISVILLE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: County Official

Deer Creek was out of its banks near Norrisville, causing localized flooding of some subdivision.  High water on was reported on roads near Bel Air, with several water rescues of stranded motorists.  Two water rescues were conducted near the intersection of Walters Mill and Ady Roads near Bel Air.

Flood in HOWARD, MARYLAND
From 16-NOV-06 18:30:00 to 16-NOV-06 21:30:00 (EST-5)
Location: SAVAGE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: County Official

Route 32 was closed near the Howard/Carroll County line due to flooding. An elderly woman became trapped in her car in Sykesville on River Road on the Howard/Carroll County line where the South branch of the Patapsco River rose our of its banks.

Flood in PRINCE GEORGE'S, MARYLAND
From 16-NOV-06 13:57:00 to 16-NOV-06 17:00:00 (EST-5)
Location: (ADW)ANDREWS AFB CAM
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Newspaper

Routes 301 and 5 were flooded.  Several roads were closed near Andrews Air Force Base due to flooding, including a section of the Interstate 495 Capital Beltway.  A farm equipment store was inundated by water in Upper Marlboro, MD.

Flood in ST. MARY'S, MARYLAND
From 16-NOV-06 16:15:00 to 16-NOV-06 18:15:00 (EST-5)
Location: ST MARYS CITY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Newspaper

Route 235 and Saint John Road flooded in St. Mary���s City, MD.

Flash Flood in BALTIMORE, MARYLAND
From 16-NOV-06 15:15:00 to 17-NOV-06 00:30:00 (EST-5)
Location: WHITE HALL
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Flash Flooding was reported in Baltimore County and the City of Baltimore. Gunpowder River rose out of its banks, allowing water to flow over the bridge at Second Mine Road.  Flash flooding was also reported at Hydes Road and Long Green Pike as well as near White Hall and Gunpowder Falls State Park.  Numerous roads were closed across Baltimore County, including a portion of Pulaski Highway (Route 40).  Roads were also closed due to flooding in the Cockeysville area.

Thunderstorm Wind in MONTGOMERY, MARYLAND
From 16-NOV-06 13:10:00 to 16-NOV-06 13:10:00 (EST-5)
Location: WOODHAVEN
Magnitude: 55.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: County Official

Thunderstorm winds knocked down powerlines and damaged a transformer in Woodhaven, MD.

Flood in CARROLL, MARYLAND
From 16-NOV-06 13:20:00 to 16-NOV-06 22:20:00 (EST-5)
Location: KEYMAR
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency Management reported water up to 2 feet deep across Twin Arch Road. An elderly woman became trapped in her car in Sykesville on River Road on the Howard/Carroll County line where the South branch of the Patapsco River rose our of its banks. The South Branch of the Patapsco River also rose out of it's banks onto Old Frederick Road, about 5 miles west of Woodbine. Route 32 was closed due to flooding near Sykesville. Numerous roads closed due to flooding near Keymar.

Thunderstorm Wind in MONTGOMERY, MARYLAND
From 16-NOV-06 13:35:00 to 16-NOV-06 13:35:00 (EST-5)
Location: LAYHILL
Magnitude: 50.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: County Official

Thunderstorm winds brought down powerlines on a car in Bel Pre.