Cold Front

A transition zone where a cold air mass advances and replaces a warm air mass.

Significant wind shift: As a cold front passes, winds shift from a generally southern direction to a generally western configuration. If the front is strong, this shift may be sharp and sudden.

Strong winds: Cold fronts tend to be preceded by low-level jets. This means winds at the surface around a cold front can be moderate and gusty depending on the depth of the low centre, which can cause turbulence due to the change in wind speed and direction associated with the front.

Convection: The warm and humid air mass ahead of the cold front along with the lift given by the cold front triggers convective weather. In the summer, this can generate rain showers and thunderstorms along the cold front. With a particularly strong front providing surface wind shear, this can yield severe thunderstorms that produce hail, downbursts, and tornadoes. In the wintertime, this zone of increased convection can produce snow squalls with whiteout conditions.

Flash freeze: The temperature gradient across a strong cold front can be quite large, and once the cold front passes temperatures can drop suddenly. If precipitation ahead of the cold front was warm and enough precipitation fell and temperatures drop quickly behind it, all the accumulated precipitation on the ground can freeze rapidly causing very slippery surfaces.