Tornado climatology of Canada revisited: tornado activity during different phases of ENSO

Tornadoes are a significant hazard in some parts of Canada, particularly in the southern Prairie provinces and southwestern Ontario, though they are not as common as in some parts of the US. Since the early 1980s, the regional weather offices in Canada have been recording tornado event information on a routine basis, and thus data exists that can be used to update older analyses of tornado frequencies. On average, about 60 tornadoes are reported each year, though many doubtless occur that are not observed or recorded in the Environment Canada records. An analysis of tornado frequencies with El Nino–Southern Oscillation (ENSO) events suggest that the cooler La Nina events tend to suppress tornadic activity, while El Nino events tend to enhance it (though there are exceptions to this trend). Copyright © 2001 Crown in the right of Canada. Published by John Wiley & Sons, Ltd.