Atmospheric and Climate Science Directorate

Severe Weather Research

Accurate and timely detection of severe weather is the best defense against the impacts of extreme weather events (i.e. tornadoes, heavy rain, freezing rain and snow) on communities. Severe weather research focuses on integrating information from surface and remote weather sensors into numerical weather prediction models for improved understanding of atmospheric processes. This will ultimately lead to improved forecast techniques and the timely and accurate detection and prediction of severe weather events and transportation hazards (i.e. fog, road and aircraft icing).

The following radar images, taken from the King Radar facility in King City, Ontario on April 20, 1996, are images of an F3 - F4 tornado approaching the town of Arthur, Ontario. Radar images are valuable weather forecasting tools used to detect severe weather.

Most strong tornadoes develop from thunderstorms with rotating updrafts (mesocyclones). The pink region marked with an arrow on the image below shows the radial velocity of precipitation moving away from the radar. The blue region marked with an arrow on the same image shows the radial velocity of precipitation moving toward the radar. These side-by-side regions of opposing radial velocities indicate counterclockwise motion.

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