Weather around the Valley, especially during the recent years of drought, tends to be predictable. Then a winter storm pushes through, temperatures plummet and there are reports of snow only a few miles outside of Phoenix.

The practicalities and science of weather will be a big part of the American Meteorological Society’s annual meeting, which opens over the weekend at the Phoenix Convention Center.

Ken Waters is the warning coordination meteorologist for the National Weather Service’s Phoenix office. He said one of the topics up for discussion is how technology has changed forecasting and increased its accuracy.