The most significant tornado, based on both its path length and intensity, was the one that sliced a 12-mile path through central Montgomery County from Poolesville to Gaithersburg.
At least two other tornadoes matched its strength, and five of the seven earned a rating of EF1 on the 0-to-5 Enhanced Fujita scale for twister intensity.
Here are details on the tornadoes which have been confirmed so far.
Central Montgomery County — EF1, peak winds of 105 mph
This tornado was born from the supercell, or rotating thunderstorm, that tracked about 100 miles from Loudoun County to Baltimore County. It first made contact near Poolesville where it toppled dozens of trees. The tornado lasted from 7:14 to 7:42 p.m. It traveled 12 miles and had a maximum width of 125 yards.
Five people were injured in Gaithersburg when a large oak tree fell on their house. Many homes and businesses were damaged from this relatively long-tracked twister.
Southern Baltimore County — EF1, 105 mph
Shortly after sunset, the same supercell that produced the Montgomery County tornado produced another near the Interstate 95 and 195 interchanges in Arbutus, Md., just to the southwest of downtown Baltimore. Numerous trees, power and phone lines were knocked over, and several buildings, including a Home Depot and an Amazon facility, sustained minor damage. The tornado was on the ground from 8:45 to 8:52 p.m., traveling 2.4 miles during that time. It had a maximum width of 175 yards.
Middle River, Md. — EF1, 105 mph
After the primary supercell passed the city of Baltimore, tornado debris was detected by Weather Service radar in Middle River, which is just to the northeast of the city. The agency’s storm survey confirmed damage to multiple mobile homes as well as downed trees. This tornado was on the ground from 8:54 to 8:56 p.m. It had a path length of 0.2 miles and reached a width of 110 yards.
Before tornadoes started to spin up in Maryland, another small supercell dropped a short-lived tornado north of Leesburg. Debris from this twister was detected on radar. The tornado mainly took down trees, but several homes had minor vinyl and window damage. The tornado occurred from 6:42 to 6:43 p.m. Along a path of one mile, it was as wide as 125 yards.
As the supercell that generated the tornado in Montgomery County swept into Howard County, it produced another twister in Columbia. It tore off roof fascia from a townhouse and toppled trees that damaged about a dozen parked cars. It made contact at 8:31 p.m. and lifted at 8:33 p.m. The path length was one mile, and it was up to 75 yards wide.
Eldersburg, Md. — EF0, 85 mph
Another supercell to the north of Montgomery County dropped the second-lengthiest twister so far confirmed from the event in Carroll County. A tree fell on a house near Eldersburg, and it was one of many toppled by the storm. This tornado was on the ground from 7:59 to 8:13 p.m. while traveling 4.4 miles. It had a maximum width of 100 yards.
Inwood, W.Va. — EF0, 75 mph
This was the first confirmed tornado of the event. It traveled mostly through a field and some wooded areas. The Weather Service documented tall grass disturbed in a rotating pattern and a number of trees were damaged. It lightly damaged shingles and gutters on a few homes. The tornado moved north from 4:04 to 4:08 p.m., progressing about 0.85 miles from start to finish. The maximum width was 65 yards.
Radar loop shows how storms unfolded
The radar animation below shows how the storms evolved. It reveals several discrete, long track supercells, several with appendages or hooks. The southernmost has a very pronounced hook, and travels a long distance, from Loudoun County across Montgomery County, and over downtown Baltimore.
This is the cell that garnered much of the real-time drama and attention, with multiple tornado sightings and videos, from Poolesville to Gaithersburg, then the Columbia area, and Arbutus and Middle River in Baltimore County. It was also the cell for which the first-ever Particularly Dangerous Situation tornado warning was issued in Montgomery County.
A composite map of rotation tracks for each supercell, obtained from Doppler radar, is shown at the top of this article. The dominant rotation track is for the aforementioned, long-track supercell. Based on Weather Service surveys, we have superimposed all known tornado tracks on these rotation corridors. Tornado track colors correspond to tornado EF intensity.
The dominant supercell that tracked through Montgomery, Howard and Baltimore counties unleashed at least four tornadoes. That’s rare for this area and would even be notable in more tornado-prone areas in the South and Plains.
Since 1950, five or more tornadoes have formed in a calendar day only 15 times Maryland. The most recent such day was Aug. 4, 2020, when 10 twisters associated with the remnants of Hurricane Isaias formed, mostly east of the Chesapeake Bay. The record for most tornadoes in a single day in Maryland is 14, which was set on July 27, 1994. There were 13 tornadoes on June 1, 2012, second most.
Should Wednesday’s count rise to 6, it will tie for seventh most on record with April 28, 2011. Eight would crack the top 5, tying the count from July 19, 1996.