The number of tornadoes so far this spring has been well below normal. The threat of these dangerous storms looks to increase for the weekend.
Why the Below-Normal Numbers
As many people noticed early in the week, temperatures have been lower than average across much of the Plains and Midwest in May.
The cooler air over this broad area is helping to hold back the number of tornadoes thus far this year.
According to Senior Vice President of Accuweather Enterprise Solutions and Severe Weather Expert Mike Smith, "We have been 'a month behind' on temperatures this spring."
Smith added that the lack of moisture has also played a role.
"Cold fronts moving across the Gulf of Mexico sweep away the moisture needed to create thunderstorms," Smith said.
Severe Potential Starting This Weekend
Unlike much of this spring so far, warm and humid air will begin to gather over the Plains helping to fuel the threat for severe thunderstorms. While isolated tornadoes cannot be ruled out, a much higher threat for tornadoes will arrive by Monday.
The greatest risk area, according to Smith, this weekend includes South Dakota, Kansas, Nebraska, Missouri, Iowa and parts of Illinois and far northern Texas.
There is definitely a potential for severe weather with storms in these areas, including large hail, damaging winds and isolated tornadoes.
At this time, it looks like the storms will likely wait until the late afternoon or evening to really fire up.
The storm is expected to come into adjust over the area on Sunday, creating a particular angle that meteorologist refer to as a negative tilt.
In a video, Severe Weather Expert Henry Margusity commented that these sort of storms "are notorious for producing some pretty nasty weather."
By Monday, powerful winds aloft will emerge into the Plains and Midwest, significantly increasing the tornado threat. Minneapolis, Des Moines, Iowa, Kansas City, Mo. and Oklahoma City will be among this increased threat.
Tornado Statistics and Outlook
Through May 7, 2013, preliminary data indicated that there have only been 237 tornadoes in the United States. This number is much below average, seeing as the tornado count as of May 7, 2012, was up to 659.
However, over the next 30-45 days, Smith says he expects to see "normal or even above-normal tornado numbers for the time of year."
Content contributed by Andy Mussoline, Meteorologist
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