The NWS survey team has concluded that the extreme damage in the Baltimore area on Tuesday night was the result of a macroburst and an EF-1 tornado.
From the NWS survey:
THE PATH OF WIND DAMAGE FROM THE THUNDERSTORMS THAT ALSO
PRODUCED THE BRIEF TORNADO STARTED ON THE WESTERN EDGE OF
MORGAN STATE UNIVERSITY IN NORTHEAST BALTIMORE CITY AND THEN
CONTINUED FOR APPROXIMATELY 5 MILES TO THE NORTHEAST TO
GUNPOWDER STATE PARK IN BALTIMORE COUNTY. IT SHOULD BE NOTED THAT
THE VAST MAJORITY OF WIND DAMAGE ALONG THE 5 MILE LONG PATH WAS DUE
TO STRAIGHT LINE WINDS FROM THE DESCENDING REAR-INFLOW JET AS IT HIT
THE GROUND…REFERRED TO AS A MACROBURST. EMBEDDED WITHIN THE DAMAGE
PATH OF THIS MACROBURST WERE TWO AREAS OF DAMAGE THAT ARE ASSOCIATED
WITH THE EF-1 TORNADO.
Basically, the damage was an isolated event wherein a localized strong burst of wind descended from the storm and slammed into the ground. This burst of wind also increased rotation in the atmosphere, which led to the formation of a brief EF-1 tornado.
Here are the Base velocity (left) and SRM velocity (right) scans of the line of storms as the tornado was reported to be on the ground. The image is courtesy of KMUWx91 from the American Weather Forums. On the right image, red pixels indicate wind going away from the radar, and green pixels are winds going towards the radar. This image indicates that there is some weak cyclonic rotation with the storm, which is a sign that there could be a tornado.