Occasional low visibility in local blowing snow and bands of lake effect flurries hit the London area Friday morning, causing a challenging commute for drivers.

Environment Canada issued another special weather statement Friday morning. A statement was also issued Thursday for snowfall.

The forecaster says bands of flurries are coming off Southern Lake Huron in a strong and gusty northwest flow of fresh Arctic air.

The Middlesex-London Health Unit also issued a cold weather alert for the region. It is the fourth one this winter.

Extreme cold is expected to descend on the London and Middlesex region this weekend, causing daily low temperatures to drop below -15 Celsius for the next few days.

Environment Canada says the mercury is expected to drop to an overnight low of -17 C Friday night, then close to -19 C on Sunday night. Temperatures Saturday and Monday nights are expected to be close to -15 C.

Snowfall amounts will likely be limited to five centimetres or less Friday, but low visibility at times in brief bursts of heavier snow and local blowing snow will result in poor winter driving conditions into this afternoon.

Elementary school buses for Oxford County Elgin County and Middlesex County were cancelled Friday, but buses within London were running.

Motorists are urged to use caution and allow extra time to reach their destination.