A surface frontal boundary was positioned north of the region across Pennsylvania for the majority of the day on May 29th, with pieces of upper level energy moving along the frontal boundary. By late in the day, a weak surface low traversed the front, and the front shifted southward towards northern Maryland as upper level energy approached the region. Hot and humid conditions across the area led to the development of significant amounts of instability, and that combined with modest but sufficient amounts of wind shear and the nearby frontal boundary promoted the development of scattered showers and thunderstorms. Some of these thunderstorms became severe, producing large hail and damaging winds, including two macrobursts across northeastern Maryland.

Hail in BALTIMORE, MARYLAND
From 29-MAY-19 16:58:00 to 29-MAY-19 16:58:00 (EST-5)
Location: BALTIMORE MARTIN ST
Magnitude: 1.50 
Reported by: Public

Ping pong ball-sized hail (1.5 inch in diameter) was reported.

Thunderstorm Wind in CARROLL, MARYLAND
From 29-MAY-19 16:09:00 to 29-MAY-19 16:09:00 (EST-5)
Location: LOUISVILLE
Magnitude: 50.00 EG
Reported by: Trained Spotter

Several trees were blown down near the intersection of MD-32 and Lakeland Drive.

Thunderstorm Wind in BALTIMORE, MARYLAND
From 29-MAY-19 17:08:00 to 29-MAY-19 17:08:00 (EST-5)
Location: SWEET AIR
Magnitude: 50.00 EG
Reported by: Trained Spotter

A tree was blown down on Jarrettsville Pike near Hess Road.

Thunderstorm Wind in BALTIMORE, MARYLAND
From 29-MAY-19 16:53:00 to 29-MAY-19 17:00:00 (EST-5)
Location: WHITE MARSH
Magnitude: 78.00 EG
Reported by: NWS Storm Survey

The White Marsh area of eastern Baltimore County was impacted with a macroburst, which caused straight-line wind damage between 5:53 PM EDT (4:53 PM EST) and 6:00 PM EDT (5:00 PM EST). Two wooden telephone poles were snapped along Silver Spring Road, and numerous trees and branches were downed along Saxon Circle. All observed tree damage fell to the northeast. Additionally, the Baltimore County Office of Homeland Security and Emergency Management reported the easternmost wind damage in Middle River, near the intersection of Ebenezer and Bird River Roads. The western most damage reported was near the intersection of Yvonne Ave and Silver Spring Rd in Nottingham. There were approximately 18 instances of tree damage between these two locations, with the horizontal distance of about 4 miles. The snapping of the telephone poles and nature of the reported and observed tree damage produces an estimate of 90 MPH wind.

Thunderstorm Wind in HARFORD, MARYLAND
From 29-MAY-19 17:08:00 to 29-MAY-19 17:08:00 (EST-5)
Location: MAGNOLIA
Magnitude: 50.00 EG
Reported by: State Official

A tree was blown down on Garnett Road near Joppa Farm Road.

Thunderstorm Wind in ANNE ARUNDEL, MARYLAND
From 29-MAY-19 17:15:00 to 29-MAY-19 17:15:00 (EST-5)
Location: SEVERNA PARK
Magnitude: 61.00 EG
Reported by: Public

Multiple trees were blown down near the intersection of Route 2 and Leelyn Drive.

Thunderstorm Wind in BALTIMORE, MARYLAND
From 29-MAY-19 16:54:00 to 29-MAY-19 16:54:00 (EST-5)
Location: BALTIMORE MARTIN ST
Magnitude: 50.00 MG
Reported by: AWOS

A wind gust to 58 mph (50 knots) was measured at Martin State Airport (KMTN).

Thunderstorm Wind in HARFORD, MARYLAND
From 29-MAY-19 17:49:00 to 29-MAY-19 17:49:00 (EST-5)
Location: HAVRE DE GRACE
Magnitude: 61.00 EG
Reported by: State Official

A roof was blown off of a house on the 200 block of North Washington Street.

Thunderstorm Wind in HARFORD, MARYLAND
From 29-MAY-19 17:10:00 to 29-MAY-19 17:15:00 (EST-5)
Location: UPPER XRDS
Magnitude: 78.00 EG
Reported by: NWS Storm Survey

The Fallston and Baldwin area of west-central Harford County was impacted by a macroburst from 6:10 PM EDT (5:10 PM EST) until 6:15 PM EDT (5:15 PM EDT), which produced damaging wind gusts estimated at 90 MPH. A concentrated area of
damage was observed starting at Moores Road in Baldwin, extending discontinuously for approximately 3.25 miles to the east, ending at Pleasantville Road in Fallston. In this area, numerous observations of tree damage were observed. The tree damage
included mainly large limbs of hardwood trees and snaps of about a dozen pine trees. Several single family homes were impacted with limbs falling onto rooftops. All tree damage fell in an easterly direction. An image circulating among residents showed what
appears to be a roll cloud, representing the leading edge of the gusty winds.