Forecasters warn the storm hitting B.C.'s South Coast could bring the worst weather of the winter season, potentially sending freezing rain down onto sidewalks and roadways.

Environment Canada has issued winter storm warnings for Metro Vancouver, the Fraser Valley, the Southern Gulf Islands and parts of Vancouver Island, indicating areas could be slammed with multiple types of severe weather.

Among them is freezing rain, which can cause treacherous conditions for pedestrians and motorists alike.

"It's the worst kind of precipitation. It creates an instant ice surface on the ground," said meteorologist Matt MacDonald.

MacDonald said freezing rain should pose less of a danger Wednesday because snow will accumulate first, but things could get so bad by Thursday morning that some people might want to think about staying indoors.

"Conditions are going to be pretty ugly on the roads so if you don’t have to travel tomorrow just stay at home,” MacDonald said.

Snow started falling in the afternoon as a warm front of Pacific air blew into the province from Washington State. It was forecast to intensify into heavy snowfall in the evening, followed by a deluge of rain.

The amount of snowfall in the forecast varies considerably across the region, from five to 15 cm near the coast and up to 20 cm further inland. Squamish was predicted to be hit with between 30 and 40 cm of snow, while Whistler could see accumulations of 50 cm or more.

When the rain starts, forecasters caution that localized flooding is possible in some areas if accumulated snow is left blocking sewer drains and catch basins.

Motorists are also advised to be extra cautious and check on conditions.

"Rapidly accumulating snow could make travel difficult over some locations. Surfaces such as highways, roads, walkways and parking lots may become icy and slippery,” Environment Canada said in an alert.

The Ministry of Transportation warned commuters the wild weather could force officials to temporarily close the Alex Fraser Bridge, or to shut down lanes on the Port Mann Bridge, if there’s a risk of falling ice and slush bombs. Crews were sent to de-ice the Alex Fraser’s cross beams and deploy cable collars on the Port Mann to prevent that from happening, however.  

Anticipating troublesome commuting conditions, several post-secondary schools cancelled classes Wednesday afternoon. Simon Fraser University's Burnaby campus announced it was closing at 1:30 p.m., followed by the B.C. Institute of Technology at 2:30. Classes were called off at all four of Kwantlen Polytechnic University's campuses starting at 4.

BC Hydro said crews are bracing for potential outages across the Lower Mainland, and warned residents to be prepared.

"You never know how much damage a storm is going to cause or how long a power outage might last, and that's why we always encourage our customers to be prepared," spokesperson Mora Scott said.

"Customers should have an emergency kit with things like flashlight, batteries, water, food and a fully charged cell phone."

Roughly half of all power outages in the province are caused by trees toppling and splitting apart, and Scott said heavy snow is already putting a strain on branches in the region.

Anyone who sees a downed power line is encouraged to keep at least 10 metres back and call 911.

For updates on BC Hydro outages, visit the utility provider's website or call 1-888-POWERON.

For the latest updates on weather warnings and alerts, visit the Environment Canada website.