An insidious danger will develop tonight

Last Saturday’s scene repeats itself

Humid air, cool nights, clear weather, light winds: Conditions will be perfect for dense fog overnight Tuesday into Wednesday. So motorists have one more element of deception during the Wednesday morning rush hour. Almost all areas of southern Quebec will be affected. Visibility may be reduced, and even zero, to less than 200 meters in places.

The ultimate mist recipe

As temperatures drop near the ground, cooler air holds less and less water vapor. When the temperature reaches the dew point, the condensation process begins, the formation of water droplets in suspension, a bit like a cloud. This is called radiation fog. At sunrise, the air warms and can hold more water vapor. The water droplets evaporate and the mist dissipates. But in autumn the sun rises, so the fog lasts for a while.

There was nothing to see on the roads on Wednesday morning

The droplets may be microscopic, but when they come together they can significantly reduce vision. Add in the presence of moisture on the road, making it even more slippery, and you have a great recipe for pileups. It’s always a good idea to limit your trips when conditions aren’t ideal. But if you have to hit the road on Wednesday morning, it’s a good idea to follow these tips:

• Reduce its speed;
• Turn on your dipped headlights;
• Keep a greater distance from the vehicle in front;
• Don’t use emergency flashers (According to the CAA, a motorist who sees a vehicle with flashing lights on may think it’s broken down and may not move. He may make an unnecessary, dangerous right-hand maneuver).

See also: This unexpected risk returns in the fall.