 Hurricane Leslie was an Atlantic tropical cyclone that had minor effects in Bermuda and Atlantic Canada in September 2012 . The twelfth tropical cyclone of the annual hurricane season , Leslie developed from a tropical wave located nearly 1 @,@ 500 miles ( 2 @,@ 400 km ) east of the Leeward Islands on August 30 . About twelve hours later , it strengthened into Tropical Storm Leslie . Tracking steadily west @-@ northwestward , it slowly intensified due to only marginally favorable conditions . By September 2 , the storm curved north @-@ northwestward while located north of the Leeward Islands . Thereafter , a blocking pattern over Atlantic Canada caused Leslie to drift for four days . Late on September 5 , Leslie was upgraded to a Category 1 hurricane . However , due to its slow movement , the storm causing upwelling , which decreased sea surface temperatures ( SST 's ) , weakening Leslie back to a tropical storm on September 7 . 
