Hurricane Isaac was a deadly and destructive tropical cyclone that came ashore in the U.S. state of Louisiana during August 2012. The ninth named storm and fourth hurricane of the annual hurricane season, Isaac originated from a tropical wave that moved off the west coast of Africa on August 16. Tracking generally west, a broad area of low pressure developed along the wave axis the next day, and the disturbance developed into a tropical depression early on August 21 while several hundred miles east of the Lesser Antilles. The system intensified into a tropical storm shortly thereafter, but high wind shear initially prevented much change in strength.
Isaac tracked between Guadeloupe and Dominica late on August 22, and then turned towards the west-northwest and entered a region favorable for intensification; it passed over Haiti and Cuba at strong tropical storm strength. A ridge of high pressure to Isaac's north intensified and turned it westward over the Florida Keys by August 26, and Isaac entered the eastern Gulf of Mexico the next day.