The reasons behind today’s sleet and snow

Yes, you read that right. Snow and sleet fell in parts of Eastern Iowa and Western Illinois this morning. According to WQAD Meteorologist Eric Sorensen, there was just enough cool air at cloud level to change the rain over to wintry stuff. "The good news is it won't last too long and it won't accumulate. All precipitation should dry up by midday today with cloudy skies expected for the afternoon."

Eric took snapshots of different types of Doppler Radar this morning and offers this little Meteorology lesson:

Reflectivity (above) shows where precipitation is falling lightly or heavily. Green is light rain, yellow and orange is heavy rain. Or is it?

This is Correlation Coefficient. This shows where there are homogeneous precipitation falling. Red is where rain is falling. Yellow indicates something other than rain. In times of severe weather, this can show where there is debris from tornadoes. In this case, since raindrops and snowflakes look different, it shows where snow is falling. 

This is ZDR or Differential Reflectivity. This shows the difference in returned energy to the radar between horizontal and vertical pulses. Differences in color represent differences in the precipitation falling.