During winter weather events you regularly hear us use the phrase ‘wintry mix’. That’s because the air temperature is not expected to stay below freezing throughout the entire atmosphere between the cloud bases all the way to the ground which means that more than just snow can form. We break down how we get each wintry precipitation type and explain why just a few degrees can make a big difference in your forecast.
Everything starts as snow in the cloud. As it falls, if the air temperature stays at 32 or below until the snow reaches the surface, it stays as snow.
However, if it goes through a small warm layer of air and then another cold layer, it slightly melts and then refreezes, turning into sleet.
Finally, there is a situation where the snow goes through a large warm layer and completely melts, before entering another freezing layer right at the surface.
“What actually happens is the temperature of the droplets falls below freezing or becomes supercooled and when this happens and it hits the ground, it freezes instantly especially when the temperature is in the upper 20’s or lower”, NWS Meteorologist Harrison Sincavage stated.
The problem with freezing rain is that when you look out the window, it is difficult to discern if it is rain or freezing rain because it is liquid in the air and this is one of the main ways that we get black ice.
“Light freezing rain events are extremely treacherous to travel, commerce, aviation.”
This is also the precip type that causes the biggest issues with power outages, just another reason to stay at home.
“If you look outside the window and you see what looks like rain, but the temperatures below 32 do not get in your car and go travel.”
Remember that it is always best to air on the side of caution during winter weather events when it comes to travel so that you can ensure that you stay safe.