Tuesday, February 23rd 2021, 10:50 pm - A unique atmospheric setup that led to wintertime lightning to strike southern Alberta Monday night, generated more thundersnow Tuesday.
After spring-like double-digit temperatures and powerful winds -- with a peak gust exceeding 160 km/h in Alberta Monday, an intense band of heavy late-night snow followed in the overnight period with thunder and lightning...in February. This happened again Tuesday afternoon, met by shelf clouds appearing over cities such as Calgary.
On Monday, social media was blown up with videos of the rare winter phenomenon, often called "thundersnow." The unique atmospheric setup and clashing air masses created just the right conditions for lightning to strike, all while heavy snow was falling at the same time.
"If temperatures become very cold aloft, above relatively warmer and moist conditions below, ample instability can develop that permits the growth of vigourous updrafts that are strong enough to cause charge separation within convective clouds, which can then lead to lightning flashes," explains The Weather Network's Kyle Brittain.
Interesting fact: Wintertime lightning is usually positive in polarity, and is especially fond of tall buildings, radio towers, and hilltops.
Thundersnow developed again Tuesday afternoon and evening, accompanied by the sight of shelf clouds in places such as Calgary. The thundersnow should dissipate through the evening hours as the band of snow will diminish by the pre-dawn hours Wednesday morning.
TEMPERATURES STILL TIPPING TO THE MILD SIDE AHEAD OF LATE WEEK COOLDOWN
A quick shot of Arctic air will spread from northwest to southeast across the Prairies Friday through Saturday, bringing a brief but abrupt transition from early spring-like weather back to mid-winter with well below seasonal temperatures for a couple of days.
The city of Winnipeg for example, will go from a high of 2°C on Friday to a high of -13°C on Saturday.
"However, the colder weather will only last a couple of days as mild Pacific air will quickly return for next week," says Weather Network meteorologist Dr. Doug Gillham.
A potent system will track from northern Alberta early Thursday morning to central Manitoba Thursday night with several cm of snow for Fort McMurray. A burst of snow and strong winds with the Arctic front is expected late in the week.
Thumbnail courtesy of Stephen West, taken in Calgary, Alta.
Be sure to check back for updates on the latest weather conditions impacting the Prairies.
Thumbnail image courtesy: Inam Jamil