May Is Notorious for Tornadoes; How Bad Will It Be This Year?

May 4, 2011; 6:26 AM ET
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After suffering one of the worst tornado outbreaks in recorded history, and what is likely to be a record-setting April for tornadoes, the U.S. will be in an extremely vulnerable state as we head through the more notorious severe weather months of May and June.

The average number of tornadoes (based on the past three years) in May is 322, while the average for June is 296, according to the Storm Prediction Center. Both of these months are typically the two most active of the year for tornadoes.

The question many people are asking now is how bad will May and June be this year, especially after such an extreme April that has yielded more than 1,000 reports of tornadoes. Expert Senior Meteorologist Dan Kottlowski warned that with abnormally cold air still in place across the northern tier of the U.S., there will still be opportunities for that cold air to contrast with substantially warmer air across the South, resulting in severe weather and tornado outbreaks.

"After all, May is typically one of the most active months for tornadoes," Kottlowski stated. "We're only about a third of the way through the severe weather season."

Kottlowski said that while there could still be several more tornado outbreaks over the next few months, the odds of having another extreme outbreak like Wednesday's is highly unlikely.

Looking to the Past for Insight to the Next Two Months

According to Expert Senior Meteorologist Ken Reeves, years in which April was an unusually active month for tornadoes typically were not followed by well-above-normal activity in May and June.

"When you see an April that is very busy, you don't typically see May and June also very active, because the pattern that really supports the very active tornadic activity in April doesn't necessarily continue it, as the threat moves farther to the north and to the east," said Reeves.

Tornadoes are a rare phenomena and require the right ingredients to come together in order to form. Reeves explained that the weather pattern that has been allowing these ingredients to come together in April typically isn't conducive to well-above-normal tornado activity in May and June.

As spring progresses, the threat for severe weather and tornadoes tends to shift northward and eastward across the Plains and East, as the jet stream, an area of maximum winds high up in the atmosphere, shifts northward.

Bottom Line: People Need to Be Prepared

Whether tornado activity over the next two months is above or below normal, there will be more tornadoes that develop. It only takes one strong tornado ripping through a community to cause devastation.

People across the country should take the time now to review tornado safety guidelines and develop an action plan for getting to a safe shelter in the event of a tornado. Mobile homes are not safe.

"There are going to be situations where tornado watches and warnings are issued in the Deep South again this year," Kottlowski said. People need to take those warnings seriously, taking appropriate, immediate action.

Businesses should also ensure they are prepared for a tornado.

"With most of the tornado season still ahead of us, it's vitally important businesses and other organizations properly plan and prepare for the next rounds of tornado activity," said Bradley J. Mitchell, Chief Commercial Officer of AccuWeather Enterprise Solutions. "Businesses certainly can and should raise the level of their game in this regard."


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