SAN FRANCISCO - Scientists are deadlocked over the severity of the next sunspot cycle, which could produce powerful solar storms that can disrupt communication systems on Earth. A panel of space weather forecasters has been sifting through about three dozen predictions from 15 nations that differ widely in how intense the next solar cycle will be. The group, run by the National Oceanic and Atmospheric Administration and funded by NASA, aims to make an official prediction in spring 2007. While scientists have observed sunspots — dark, cool blemishes — on the sun's surface since the days of Galileo, they've been...