Weather: Rain Math

Ever been caught umbrella-less in an unexpected afternoon rain shower? Thanks to a simple mathematical formula developed by scientists in Israel at the Weizmann Center's Department of Physics and Complex Systems, the days of meteorological uncertainty (and an extra umbrella at work) may be over. According to Prof. Gregory Falkovich, who created the formula with graduate students, the algorithm combines new theoretical work by the Weizmann team with older, fairly established, physical principles.

By plugging a few easily measurable variables into the formula, Falkovich says, forecasters may soon be able to more accurately predict rain a few days in advance and "within 15 to 20 minutes and miles of its fall" (present estimates are usually in hours and counties). In the future, the theorem may also help scientists to better manage rainfall, a potentially significant development for regions (Israel, for example) that rely heavily upon rain to augment water supplies. While secondary applications like this are farther afield, forecasters are hankering to get their hands on the theorem, and anything else that will bring more precision to the uncertain task of weather prediction. "Wow!" remarked New York City WNBC meteorologist Janice Huff upon hearing of the development. "Now our viewers might actually think that we know what we're talking about."