Weather Blog

What makes the Midwest "Tornado Alley"?

What makes the Midwest "Tornado Alley"?
The area in the Midwest around Oklahoma, Nebraska, Missouri and northern Texas is commonly known as "Tornado Alley" due to their frequent tornadoes in the spring, summer and fall. But ever wonder what makes them so vulnerable? Tornado Alley is a frequent battleground between the cold, dry air coming south out of central Canada, and warm, moist air being pulled north from the Gulf of Mexico.

Where these two air masses meet are favorable for very strong storm development, and the greater the difference in temperatures between the two masses, the stronger the storms can be.

Tornadoes are most frequent in the spring time because we still have leftover arctic air in Canada from winter to sink south, but the Gulf region has already got a head-start on their warm summer temperatures. We also get a burst in autumn, but it's not as bad as the springtime.

The mean season begins in late winter/early spring along the Gulf of Mexico, then migrates northward during the spring as the season warms and gulf air makes inroads farther north. But tornadoes can happen any day of the year if you get a strong enough storm and the atmosphere is primed.

And yes, they can happen anywhere too.  Washington and Oregon are not immune from tornadoes -- each state averaging about one tornado a year.