Dear Bob,
Why is it very rare for a tornado to happen in Europe?
Bob Price, Joliet

Dear Bob,

It is certainly true that tornadoes in the United States far outnumber occurrences in Europe. About 1,275 tornadoes touch down in the United States annually, but their number varies considerably from year to year. Europe reports about 650 tornadoes annually. Geography plays the major role in this dispairity. Europe, approximately the same size as the United States, lies farther north in latitude and mountain ranges are predominantly east-west. Thus polar, and tropical air masses usually do not come in direct contact with each other like they do over the central U.S. This lends to less volatile conditions. Europe also experiences a more stable, marine west coast type climate.