The Earth Science Picture of the Day Photographer: Roberto Giudici Summary Authors: Roberto Giudici; Jim Foster "The photo above shows an eye-popping complex of waterspouts I observed over the Adriatic Sea on a boat trip to Brindisi, Italy. As we departed, the weather was very summer like -- some humidity, hot and sunny. Cumuliform clouds developed during our excursion, but the weather didn't appear threatening. In fact, the atmospheric pressure was stable at 1024 millibars. Suddenly, we saw a line of funnel clouds straight in front of our boat! The photo shows the most recently formed waterspout in the foreground; the oldest spout, in the background, would disappear in a few seconds. Our boat actually passed through the scary funnels. The spouts were spaced about 1/3 nautical mile from each other. I asked the boat's captain if he thought cruising past the spouts would be dangerous, but apparently, he wasn't bothered much by their proximity. Nevertheless, waterspouts can generate winds of over 70 mph (F0 on the enhanced Fujita Scale) and can be hazardous to boaters. Othoni Island is at left center. Photo taken on July 23, 1999."