Medium chance of cyclone near Yucatan Peninsula: NHC Wed Sep 11, 2013 7:53am EDT (Reuters) - A large area of cloudiness and thunderstorms over the northwestern Caribbean Sea and the Yucatan Peninsula has a medium 40 percent chance of becoming a tropical cyclone during the next 48 hours, the U.S. National Hurricane Center said in its latest bulletin. "If the system remains over water, upper-level winds should be conducive for additional development later in the week," the NHC said. Reporting by NR Sethuraman in Bangalore; Editing by Lisa Von Ahn