An upper-level low over the Great lakes provided cooler air aloft. The warm and humid air at the surface combined with the cooler air aloft to allow for an unstable atmosphere. Showers and thunderstorms popped up on the 26th over Maryland. The winds aloft were strong enough for some thunderstorms to become severe.

Thunderstorm Wind in MONTGOMERY, MARYLAND
From 26-JUL-09 15:57:00 to 26-JUL-09 15:57:00 (EST-5)
Location: DICKERSON
Magnitude: 55.00 EG
Reported by: NWS Employee

Large trees were blown down. Large branches were also down along Route 28 near the Monocacy River Bridge.

Thunderstorm Wind in FREDERICK, MARYLAND
From 26-JUL-09 15:51:00 to 26-JUL-09 15:51:00 (EST-5)
Location: PLEASANT VIEW
Magnitude: 55.00 EG
Reported by: Newspaper

A large tree was down and there was structural damage to a machine shed.

Thunderstorm Wind in BALTIMORE, MARYLAND
From 26-JUL-09 17:05:00 to 26-JUL-09 17:05:00 (EST-5)
Location: TYLER
Magnitude: 60.00 EG
Reported by: Emergency Manager

Trees and power lines were down on Deer Park Road. A tree fell onto a house.

Thunderstorm Wind in BALTIMORE, MARYLAND
From 26-JUL-09 17:06:00 to 26-JUL-09 17:06:00 (EST-5)
Location: DELIGHT
Magnitude: 60.00 EG
Reported by: Emergency Manager

Trees and power lines were down on Cherry Hill Court. A tree fell on a house.

Thunderstorm Wind in BALTIMORE, MARYLAND
From 26-JUL-09 17:06:00 to 26-JUL-09 17:06:00 (EST-5)
Location: TYLER
Magnitude: 60.00 EG
Reported by: Emergency Manager

Numerous trees were down and trees fell on houses at the intersection of Berrymans and Church Road.

Thunderstorm Wind in BALTIMORE, MARYLAND
From 26-JUL-09 17:05:00 to 26-JUL-09 17:05:00 (EST-5)
Location: DELIGHT
Magnitude: 55.00 EG
Reported by: Emergency Manager

Trees and wires were down on Sunbrook Road.

Thunderstorm Wind in HOWARD, MARYLAND
From 26-JUL-09 16:35:00 to 26-JUL-09 16:35:00 (EST-5)
Location: LISBON
Magnitude: 50.00 EG
Reported by: Trained Spotter

Trees were down along Route 94.

Thunderstorm Wind in HARFORD, MARYLAND
From 26-JUL-09 18:02:00 to 26-JUL-09 18:02:00 (EST-5)
Location: GIBSON
Magnitude: 50.00 EG
Reported by: Emergency Manager

A large tree was blown onto power lines near Hickory.

Thunderstorm Wind in HARFORD, MARYLAND
From 26-JUL-09 18:02:00 to 26-JUL-09 18:02:00 (EST-5)
Location: GIBSON
Magnitude: 50.00 EG
Reported by: Emergency Manager

A large tree was blown onto power lines near Hickory.

Thunderstorm Wind in HARFORD, MARYLAND
From 26-JUL-09 18:24:00 to 26-JUL-09 18:24:00 (EST-5)
Location: LAPIDUM
Magnitude: 60.00 EG
Reported by: Emergency Manager

Trees were topped and numerous branches were snapped. Trees two to three feet in diameter were blown down with power outages reported.

Thunderstorm Wind in BALTIMORE, MARYLAND
From 26-JUL-09 17:05:00 to 26-JUL-09 17:05:00 (EST-5)
Location: HOLBROOK
Magnitude: 50.00 EG
Reported by: Trained Spotter

A tree was blown down on Lyons Mill Road.

Thunderstorm Wind in CARROLL, MARYLAND
From 26-JUL-09 16:52:00 to 26-JUL-09 16:52:00 (EST-5)
Location: ELDERSBURG
Magnitude: 50.00 EG
Reported by: Trained Spotter

Several tree branches were down in Eldersburg.

Thunderstorm Wind in BALTIMORE, MARYLAND
From 26-JUL-09 17:06:00 to 26-JUL-09 17:06:00 (EST-5)
Location: OWINGS MILLS
Magnitude: 50.00 EG
Reported by: Law Enforcement

Multiple trees were down in Owings Mills.

Thunderstorm Wind in BALTIMORE, MARYLAND
From 26-JUL-09 17:05:00 to 26-JUL-09 17:05:00 (EST-5)
Location: TYLER
Magnitude: 50.00 EG
Reported by: Emergency Manager

Trees and power lines were down on Deer Park Road.

Thunderstorm Wind in BALTIMORE, MARYLAND
From 26-JUL-09 17:05:00 to 26-JUL-09 17:05:00 (EST-5)
Location: TYLER
Magnitude: 60.00 EG
Reported by: Emergency Manager

Numerous trees were down. Trees fell on houses in the Church Road Area.

Hail in ST. MARY'S, MARYLAND
From 26-JUL-09 14:37:00 to 26-JUL-09 14:37:00 (EST-5)
Location: ST INIGOES
Magnitude: 0.75 
Reported by: Trained Spotter

Penny size hail was reported Saint Inigoes.

Hail in ST. MARY'S, MARYLAND
From 26-JUL-09 14:38:00 to 26-JUL-09 14:38:00 (EST-5)
Location: DAMERON
Magnitude: 0.75 
Reported by: Trained Spotter

Penny size hail was reported in Dameron.

Hail in HOWARD, MARYLAND
From 26-JUL-09 16:38:00 to 26-JUL-09 16:39:00 (EST-5)
Location: LISBON
Magnitude: 0.75 
Reported by: Fire Department/Rescue

Penny size hail was reported in Lisbon.

Hail in BALTIMORE, MARYLAND
From 26-JUL-09 17:17:00 to 26-JUL-09 17:17:00 (EST-5)
Location: BELLTOWN
Magnitude: 0.75 
Reported by: Trained Spotter

Penny size hail was reported in Owings Mills.

Hail in HARFORD, MARYLAND
From 26-JUL-09 18:02:00 to 26-JUL-09 18:02:00 (EST-5)
Location: GIBSON
Magnitude: 1.00 
Reported by: Trained Spotter

Quarter size hail was reported near Hickory.

Hail in HARFORD, MARYLAND
From 26-JUL-09 18:04:00 to 26-JUL-09 18:04:00 (EST-5)
Location: FOUNTAIN GREEN
Magnitude: 0.75 
Reported by: Trained Spotter

Penny size hail was reported near Bel Air.

Hail in HARFORD, MARYLAND
From 26-JUL-09 17:14:00 to 26-JUL-09 17:14:00 (EST-5)
Location: LAUREL BROOK
Magnitude: 1.75 
Reported by: Trained Spotter

Golf ball size hail was reported near Fallston.