During winter, the precipitation type is determined using information from the WRF model called Condition Precipitation Type. WDT’s Conditional Precipitation Type (CPT) product indicates the type of precipitation at the surface if precipitation were to occur. By using Level II mosaics, we can discrimate between rain, snow and freezing rain.

The product is generated from WRF forecasts that WDT performs on a 28-km grid covering the conterminous U.S. and southern Canada (Carpenter et al., 2004). A six-hour forecast is run every hour, with output available at 15 minute intervals.