There's nothing like storm season to make television stations hang themselves on ropes threaded with embellishments. Come spring, the slightest mention of a tornado sends news directors scrambling for the best severe-weather reporting. Well, call off the contest, because Channel 5 has a gimmick that slays the rest. The station not only dispatches an army of reporters during storms but also augments each phoned-in report with an onscreen photograph of the reporter talking on a cell phone. Come next tornado warning, tune in to Channel 5 and check it out. When your amusement over that urgency-turned-cheeseball effect wears off, think about this: At some point on some great day, super-reporter Dave Helling actually had to take time out to pose with a Motorola pressed to his head.