A winter warm front is draped across the region! For many, that sounds lovely, but it can be a traveller’s nightmare. The warm front is not producing very much precipitation, but the type of precipitation is a concern.
Let’s start on the warm side of the system, where you’ll find drizzle, fog and showers. That sounds harmless, but it’s treacherous on gravel roads in rural areas. The ground is frozen, therefore light rain or drizzle will freeze on contact and turn snow-packed sideroads into skating rinks.
Along the front, you’ll find freezing drizzle or light freezing rain: that’s a real issue on paved roads. Freezing rain falls as a liquid. It freezes when it comes into contact with a very cold surface forming a thin coat of ice. Commuters are often fooled by this one, because the car windshield is warm, freezing rain doesn’t freeze to it. The roads are not heated, so those same super-cooled droplets freeze on contact with the cold surface of the road.
The front that’s stretched across Atlantic Canada is not pushing through but is oscillating overhead instead. A slight shift to the south and rain becomes mixed with ice pellets. Ice pellets fall on the colder side of a warm front during the colder months. They form when snow melts in warmer air and then refreezes before it hits the ground. Some people incorrectly refer to these as hail, but hail falls from a convective cloud – usually a summer storm.
So, there you have it – hail is most often associated with thunderstorms, freezing rain falls as a liquid and ice pellets are little pieces of ice that make quite a racket when they hit the window!
By Wednesday afternoon, we won’t have to worry about the problems that arise when the temperature is above freezing in the winter – a cold north wind will bring temperatures down as the day goes on!
Have a weather question, photo or drawing to share with Cindy Day? Email firstname.lastname@example.org
Cindy Day is the chief meteorologist for SaltWire Network.