There were two tornados in the Washington D.C. vicinity last night. While these
do not strictly count as subjects for a earthquake discussion, I thought the members
of this board would be interested in some details not commonly reported.
From reports received here, the tornados appear to have formed near the
Pentagon and the Washington Monument. Dark swirling clouds were seen
converging over the Capitol Rotunda where they stayed for a few minutes. Two
people were killed and several hundred injured in these storms. I have attached
a link to a news story below.
The last confirmed report of a tornado causing deaths in the central Washington, D.C. area
was on August 25, 1814. A tornado hit Washington during the burning of the
Capitol and the White House by British Soldiers. "Roofs of houses were torn off ...
and whisked into the air like sheets of paper." British soldiers devastating Washington
were killed in the storm.

Three other tornados have caused deaths in the Maryland-Delaware region -
these were a F2 tornado on August 21, 1888 which caused 11 deaths; Nov. 9, 1926
(17 deaths) and June 23, 1944 (32 deaths). Only one tornado has caused more
injuries in the region - the June 23, 1944 tornado caused 300 injuries in the region of WV,
PA and MD - this was a family of twisters.

It is very unusual to get tornados in the area this late in the season. Only
4 tornados have occurred in October or November (none in Dec, Jan or Feb)
in the Maryland/Delaware DC area. 49 tornados have reported in the area since
1885.

The tornados follow the strong geomagnetic storm of 23 September. Because
tornados systems begin high in the troposhere in regions disturbed by
geomagnetic storms, it has been speculated that there may be a causal relationship
be strong geomagnetic storms and the occurrence of some types of tornadic activity.

• News account of Washington D.C. Tornados