Problem: The National Weather Service's Storm Prediction Center has issued a tornado watch on a warm spring day. The watch covers a large area believed to be at risk for severe weather, including tornadoes. Late in the afternoon, Storm Spotter A sees a storm that has numerous updrafts oriented in a perfectly upright fashion. Storm Spotter B sees a storm with a single, rotating updraft that tilts downwind. Which, if either, of the storm spotters should interpret their storms as an immediate threat?