Meteorologists are warning drivers to be cautious along one of the province's most treacherous highways.

A snowfall warning is in effect for parts of British Columbia including a stretch of the Coquihalla Highway. Environment Canada forecasts that as much as 20 centimetres of snow may fall between Hope and Merritt, prompting a warning from the agency to drivers.

"Be prepared to adjust your driving with changing road conditions," the warning read.

Coquihalla snowfall warning

"Prepare for quickly changing and deteriorating travel conditions. Visibility may be suddenly reduced at times in heavy snow."

The warning was prompted by a weather system hovering over the area bringing heavy snow to the Coquihalla Summit. Environment Canada expects between 15 and 20 centimetres of snow to accumulate by the evening.

Snowfall warning for Coquihalla

And the Coquihalla was not the only highway that fell under Tuesday's snowfall warning.

A similar warning was issued for Highway 3 between Paulson Summit and Kootenay Pass, although the forecast called for between five and 15 centimetres of snow in that area.

The snow falling Tuesday is in addition to a storm that hit both areas overnight, which dumped 15 centimetres over part of the Interior. The snow is expected to taper off, and the warning ended shortly before 3:30 p.m.

Those travelling on either highway are asked to check conditions on www.drivebc.ca before heading out. Webcams are available online showing specific portions of provincial highways.

But drivers are also warned that conditions can change at any minute, especially in mountainous areas.

With files and photos from CTV Vancouver's Julie Nolin

Snowfall warning on Coquihalla Hwy