Days with at least 4 tornadoes in Maryland between 1950 and 2011. Note it does not include the June 1, 2012 outbreak with 11 twisters verified so far. (Jared Klein - Natonal Weather Service)

UPDATE: The June 1 Md. tornado count is now up to 12. NWS has confirmed an EF-0 tornado that touched down near Poolesville in Montgomery county (technically 4 miles north northwest of Countryside in Virginia). Full list.

From earlier: The number of confirmed tornadoes on June 1 in Maryland has risen to 11, second most in a single day in state records. The event passes the 9 that occurred August 28, 1992 (spawned by the remnants of Hurricane Andrew) but still trails July 27, 1994 when 14 tornadoes touched down in the state.

(Note: 11 tornadoes occurred within 24 hours last year in Maryland , but over a span of two days, April 27-28)

Tornado records have been maintained since 1950. Since tornado detection has improved significantly in the last two decades, it’s quite possible there was comparable (or greater) activity prior to the 1990s.

Link: Shock stat: Maryland has third highest tornado density in U.S.

The 11 tornadoes on June 1 are enough to already exceed the annual average of 10.

The National Weather Service office in Sterling, Va. lists 8 tornadoes that were confirmed in Maryland on June 1 on its website. Since Tuesday, two additional tornadoes have been confirmed: 1) an EF-0 tornado that touched down near Simpsonville in Howard county 2) a small tornado that touched down in Alleghany county. The 11th tornado occurred under the jurisdiction of the NWS Office in Mt. Holly, Pa, in Queen Anne county in Maryland, east of the Chesapeake Bay.

It’s possible two additional tornadoes will be added to the list. The NWS-Sterling office is surveying damage near Poolesville in Montgomery county and Indian Head in Charles county to determine if twisters touched down.

The active start to the tornado season in Maryland follows the second most active year on record for tornadoes in Virginia. In 2011, about 50 tornadoes touched down in the Commonwealth.

(Ian Livingston contributed to this post)

Link : Maryland Listing of Historical Tornadoes by County