(WFRV) – The possibility for a wintry mix comes with many storms throughout the winter season. That mixed precipitation can come in the form of graupel (sleet) or freezing rain. How do these differ from regular rain and snow?
It is all dependent on the freezing layer. This means how much cold air exists where temperatures are below 32 degrees.
Demonstration
Vegetable oil will represent warm air or temperatures over 32 degrees. Temperatures below 32 degrees will be represented by water mixed with blue food coloring.
Each of these cups will signify, rain, sleet, freezing rain and snow. In this scenario, assume freezing precipitation like snow if falling into these cups.
Snow: frozen precipitation where temperatures are entirely below freezing from the cloud to the surface. Entire cup is blue water, or temperatures below 32 degrees.
Sleet or graupel: frozen precipitation falls into an area of shallow warm air, then refreezes before hitting the surface. Some warm air is in the cup, but most the cup is below freezing or blue.
Freezing Rain: frozen precipitation melts in warm air. Rain falls as a result, before refreezing on the surface of the ground. Most of the cup is filled with vegetable warm air, with the surface being blue for cold air.
Rain: precipitation melts in warm air, if it was not already melted, never refreezes when falling or hitting the ground. The entire cup is vegetable oil which represents temperatures above freezing.
For more Science Course with Ryan Morse, click below
Lake Michigan can be a source for mixed precipitation in Northeast Wisconsin. When water temperatures are warmer than land temperatures, an onshore breeze is all that is needed to caused mixed precipitation in parts of Northeast Wisconsin.
