Bill Edwards in Trappe saw a TV program about the use of chemicals "to divert or stop rain. ... I have noticed on many weekends that rain is predicted [but] it does not rain in this area. Curious." Forecasters can be wrong, and summertime showers can be hit-or-miss. The National Academy of Sciences found that, except for dissipating rare "cold fog," cloud seeding for weather control is "an act of faith," not science.