Year 2023 is off to a picturesque start in southern Manitoba and Saskatchewan, thanks to the frost-like dusting parts of the province underwent over the past few days.
CTV News Winnipeg viewers have submitted dozens of photos of the pleasing precipitation, coating trees, fences and homes to look like Currier and Ives prints.
Environment and Climate Change Canada meteorologist Terri Lang said the precipitation that’s popping up across social media is likely rime icing resulting from a few days of foggy skies.
She said this form of precipitation happens when fog and cloud droplets are floating around the atmosphere, even though the temperature is well below freezing. These droplets can exist in the atmosphere even when the mercury dips as far as -25 Celsius, she said.
Rime ice, shown in this photo taken in Winnipeg's Windsor Park neighbourhood, is created from the direct freezing of water droplets. (Source: Mandy Snell)
“When those little droplets of liquid encounter something that's below freezing, they'll just automatically freeze onto them. So that's trees, that's buildings, that's the roadway, that's your car,” Lang told CTV News Winnipeg in a phone interview.
“It’s so beautiful.”
The La Barriere Park foot bridge flanked by rime ice-covered trees is shown in this Jan. 4 photo. (Source: Claude Mousseau)
Lang notes rime icing can sometimes be mistaken for hoar frost, which occurs during clear skies, when water droplets undergo sublimation, which means it transitions from solid to gas, skipping the liquid phase.
“Because of the liquid, rime icing looks different. It looks heavier. It coats more of the trees. It’s not as easy to blow off, like hoar frost,” she said.
DYK: the difference between hoar frost and rime icing has to do with sky condition?
— ECCC Weather Manitoba (@ECCCWeatherMB) January 5, 2023
The short answer is: if it's foggy, that can lead to rime icing (direct freezing of water droplets)
If it's a cold, clear night that can lead to hoar frost (sublimation of water droplets)#MBstorm pic.twitter.com/tSNZJbn00K
THE REASON BEHIND THE PERSEVERING PRECIPITATION
Lang notes the rime ice has stuck around for so long because of a lack of weather systems moving through our atmosphere.
“They're hitting California, they're hitting the B.C. coast, they're going through the Northwest Territories, so we're kind of lacking wind, and we're lacking anything to mix the atmosphere up,” she said.
A CTV viewer snapped this rime ice-coated tree in a field off Highway 206. (Source: Linda Rosenthal)
However, a weather system that could move through northern Manitoba Friday could bring some more wind up from the south, likely dissipating the fog and cloud coverage.
“But then it looks like after that, probably by Saturday, it’s going to reform again.”
RIME ICE CAN BE PRETTY, BUT DANGEROUS: ECCC
While pretty, rime icing can also be a hazard.
Lang said it can create issues with roads and power lines.
“If you have a really long period of this rime icing, that can go on for days, it can start weighing down the lines and the infrastructure on the power lines,” she said.
Power lines near St. Leon are seen covered in rime ice in this Jan. 4 photo. (Source: Manitoba Hydro)
Manitoba Hydro tells CTV News Winnipeg there is quite a bit of ice accumulating in the southwestern part of the province, near Killarney and Morden.
“We’re already coordinating de-icing in those areas and have been on high alert about it for a couple days,” said Riley McDonald with Manitoba Hydro.
“Sometimes we may have to take a power outage to de-ice a line. Right now we’re not doing that, but it may be a possibility. If we did require a power outage for de-icing, we have several ways of notifying customers.”
Customers are asked to let Hydro know if they see heavily iced, sagging or galloping power lines through the comment form on its online outage report or by calling 1-888-MB HYDRO (1-888-624-9376).
Post a Comment