As the clash of seasonal air masses is upon us, so is the secondary peak of tornadic activity, across the United States. This peak in activity is no where near as intense as what happens during the spring time. This secondary peak of activity has to do with the combination of fast Jet Stream winds and strong
frontal systems. A strong gradient of temperatures across the hemisphere
typically drives these powerful Jet Stream winds, and creates much stronger
frontal systems which help initiate thunderstorm development.
Typical October Pattern
We do not have to go back far at all to see active Fall tornadic months. In fact, 2010 was an extremely active October and November for tornadoes. Some of the tornadoes last year were even strong and ranked in ef-4 intensity. Weather patterns, with regards to La Nina, are to last year's. So, expect severe weather season to pick up has we head deeper into the fall months.