Virtual Snow Machine

With the winter winding down, many snow fanboys in the Washington metro area are bitterly disappointed as what was advertised to be a major snowstorm today appears to be seriously underperforming, especially west of the I-95 corridor. If you're feeling cheated by the ongoing snow drought, or if you just want to learn more about the precipitation process, Steve Ackerman and Tom Whittaker of the University of Wisconsin have a very slick Java applet for teaching precipitation types based on the distribution of temperature and humidity. Drag around the temperature (green line) and dew point (yellow line) and see how that affects the type and amount of precipitation, if any, reaching the ground. See if you can produce all 7 possible precipitation types. If you thought precipitation forecasting was just watching radar blobs move around, this tool shows there is much more going on in the third dimension.

Image (click to enlarge): Example from precipitation type applet by University of Wisconsin