Dan Drollette writes: Contrary to some items making the rounds of the Twitterverse, El Nino's are "Kryptonite for hurricanes." The Mercury News reports: "Irma has ripped a path of misery through the Caribbean and is aiming at Florida, but the first seed for its monster size and force was planted on the other side of the world more than six months ago. It happened innocently enough, when a widely anticipated El Nino failed to materialize over the Pacific Ocean. In time, that cleared a path for a hurricane to form in the Atlantic that grew to the size of the state of New York with winds topping 185 miles per hour. El Nino occurs when the Pacific heats up and flusters the atmosphere, setting off a chain reaction that causes wind shear across the Atlantic. Shear is wind blowing in different directions or speeds at various altitudes, and it can be Kryptonite for hurricanes. As powerful as they are, tropical cyclones have delicate structures. Shear can tear them apart. A budding storm can't get started and an established storm can't get strong."