Environment Canada is warning Hamilton residents to brace for a potential ice storm overnight Monday into Tuesday and the local electricity company says there could be some downed power lines.

Expect slippery roads, highways, walkways and parking lots, says the forecaster's freezing rain warning.

There will be rain and temperatures falling below zero. And "poor weather conditions may contribute to transportation delays," Environment Canada says.

Also, avoid driving, downed branches and power lines, the warning says.

Alectra Utilities (formerly Horizon Utilities) issued a special weather statement Monday too. Fallen branches and wires cause power outages, it said.

Stay at least 10 metres away (the length of a school bus) from power lines, the advisory says. To report outages, call the following numbers:

Hamilton: 905-522-6611

Mississauga: 905-273-9050

St. Catharines: 905-684-8111

York Region/Simcoe County: 1-877-963-6900

The utility will also give frequent updates on Twitter.

Hamilton/St. Catharines — @alectra_HamStC

Mississauga — @alectra_Sauga

York Region/Simcoe County — @alectra_YorkSim

People call also tweet using the hashtag #ONStorm to inform Environment Canada of severe weather.

Here's the forecast for the next two days: