Enjoy the spring-like weather while it lasts, Toronto — another cold snap is on the way.
Though temperatures in the city are expected to hover around 3C Thursday, they’re expected to plummet to -7C overnight, according to Environment Canada meteorologist Mark Seifert.
“The rain is going to end,” said Seifert. “It’ll end before the temperature falls below zero.”
Temperatures are expected to remain below zero until Monday.
The current weather conditions could also lead to extra snowmelt and possible ice breakups in the GTA’s various rivers and streams, elevating the risk of flooding, said the region’s watershed authority.
“The possibility exists for flooding on roadways and in low-lying areas,” read a warning issued by the Toronto and Region Conversation Authority Thursday morning.
“The combination of slippery and unstable banks, unsafe ice and cold water temperature will create hazardous conditions close to any river, stream or other water bodies.”
Drizzle continued to fall in the city Thursday morning, the remnant of a weather system that caused a rainfall warning overnight.
Toronto received about 15 mm of rain overnight — within the range Environment Canada predicted — and could see another 5 mm before the day’s over, said Seifert.
But there’s no precipitation in the forecast again until Tuesday, when Environment Canada says we might see periods of snow or rain.
Temperatures will remain below freezing for the next three days. They may get as low as -12C on Friday night, but will likely be only a few degrees below zero during the daytime as the weekend begins.
However, Seifert said most of the past day’s rainfall will likely have the chance to dry up or drain away before the cold sets in, meaning icy roads are less likely to be a widespread problem.
“I don’t foresee a big flash freeze,” he added.
Environment Canada detected a peak temperature of 9C in Toronto overnight, said Seifert. But as the latest weather system swept towards the city from Michigan, Seifert said temperatures were already dropping early Thursday by the time most Torontonians were starting their day.
Thursday morning, at least, Lake Ontario was the warmest place to be in Canada, Environment Canada reported. It was nearly 13C at the St. Catharines airport at 7 a.m. — a far cry from the -42C temperatures recorded in Stony Rapids, Sask. at the same time, the coldest in Canada.
Though Thursday’s high is unseasonably warm, it’s not record-breaking. Temperatures reached nearly 15C on the same day in 2013.
But the arrival of the cold snap may give Torontonians something else to worry about. A new study suggests that a sudden drop in temperatures can “kickstart” flu epidemics, meaning the forecast could be detrimental for already-climbing flu activity in Toronto. The University of Gothenburg’s study of 20,000 virus samples, the results of which were released last month, also suggested weather could play a role in other common viruses as well.
So far, the number of flu cases this season has been higher than the average for the last 10, said Toronto Public Health in their most recent report, released Jan. 6. One person has died from the virus so far this season.