NCEP ETA PRECIPITATION TYPE ALGORITHM, AT HPC WE NOW ALSO USE ALGORITHMS DEVELOPED BY RAMER AND CYS
BLUE SHADED AREA IS WHERE MODEL SOUNDING SUGGESTS SNOW, VIOLET WHERE IT INDICATES SLEET AND RED FREEZING RAIN, DARKER BLUE LINES INDICATE RH, WHITE LINES INDICATE VERTICAL MOTION.
If model has problems handling mass, wind or temperature fields, then its forecast of precipitation type will be wrong