Environment Canada upgrades potential ice storm warning for Southern Ontario

Londoners’ hopes of welcoming spring-like weather this weekend could be dashed by bouts of freezing rain.

Residents are being cautioned to brace for freezing rain and gusting winds this weekend

An ice storm could see parts of the province get in excess of 20 millimetres of rain or freezing rain this weekend, Environment Canada is warning. (Kate Bueckert/CBC)

Londoners' hopes of welcoming spring-like weather this weekend could be dashed by bouts of freezing rain.

Environment Canada upgraded a special weather statement to a freezing rain warning for much of Southern Ontario, including London, Parkhill, Strathroy, Komoka and Middlesex County, warning of a potential ice storm Saturday and Sunday.

The forecast calls for rain ahead of a slow moving system from the Gulf of Mexico that is expected to change to freezing rain beginning Saturday morning as cold air is drawn in from the north.

"It's not common, but I wouldn't say it's rare. It's the type of storm we should expect during the transition period in the spring," said Environment Canada warning preparedness meteorologist Etienne Gregorie.

"These storms become very intense. There's this clash of all this warm air that's sitting along the Atlantic and in the Southern U.S., and then running into still cool, cold weather here, they spool up and become quite major."

As cold air makes its way into the region, many areas could see over 20 millimetres of freezing rain on Saturday, with significant amounts of ice possible, along with gusting winds up to 60 km/h.

According to the national weather service, the majority of freezing rain is expected to hit north of London from the shores of Port Elgin, across Kitchener-Waterloo and on to Kingston. A freezing rain warning is in effect from Huron County to Kingston-Prince Edward County.

Don't expect sun

Residents are being cautioned to prepare for the possibility of widespread power outages due to fallen tree limbs and power lines, along with icy road conditions.

"If you're heading toward Chatham and Windsor, the threat of freezing rain is minimal. But if you're heading toward the GTA or Georgian Bay, you're going to run into this freezing rain," said Gregorie.

Flooding may also become a threat in some areas as temperatures rise above freezing and heavy precipitation persists into Sunday.

The Upper Thames River Conservation Authority (UTRCA) has issued a flood watch bulletin with total precipitation amounts expected to reach over 60 millimetres.

"At this time, water levels are not expected to be as high as the recent event in February of this year," said UTRCA communications manager Teresa Hollingsworth in a statement.

The conservation authority warns that water levels are expected to peak on Monday morning in Mitchell, Stratford, and Woodstock and then later in the day in London.

Water levels are expected to remain elevated throughout the week.

While the rain is expected to taper off Monday, Environment Canada isn't forecasting any warm weather for the rest of the week.

"There is no sign of a long period of sunshine and 18 degrees, we just don't see the sun on the short term horizon," said Gregorie.