The 1st April marks the start of what is typically the most active & dangerous three-month period of the year for Tornadoes in the U.S.
Significant Tornadoes can happen in any month, as “we saw in early March” when twenty three lives were lost in the EF-4 Lee County, Alabama Tornado.
However, history illustrates April, May and June are the months with the highest potential of having both the greatest number of Tornadoes…
… and the most intense Tornadoes in a given year.
During nineteen years (1998 – 2017), the U.S averaged one thousand two hundred and thirty nine Tornadoes – which were crammed between April and June.
May has seen the most Tornadoes each year, an average two hundred and seventy nine.
Followed by June and April – which average around two hundred and thirteen + one hundred and ninety two Tornadoes per year.
The amount of Tornadoes from April to June is not the only reason why it makes it such a dangerous time of year – their intensity is also a factor.
According to Dr. Greg Forbes of The Weather Channel, fifty eight per cent of all Tornadoes are rated EF3 or stronger (1950 – 2012) touched down in the above mentioned months – statistics revealed.
The percentage grows to sixty nine perfect – relating to EF-4 Tornadoes (1950 – 2012) or stronger. The EF5 rating has been applied to fifty nine Tornadoes dating back to 1950 – all but ten happened in April, May or June.
All Tornadoes significally pose a threat, however the most intense account for the higher number of deaths and damage.
Eighty three per cent of the deaths from the year 2000 to 2013 were from Tornadoes rated EF-3 or stronger, according to Forbes.
Suffice to say eight of the ten worst U.S Tornado outbreaks happened in April or May. The reason why? Mostly due to the fact that upper echelon Tornado intensities are more likely in those months.
Furthermore, nine out of the ten worst separate Tornadoes were spawned during April, May or June.
Why are Tornadoes more common in spring compared to other months? Simple! The atmospheric elements come together more often this time of the year.
Outbreaks of Tornadoes tend to happen when a storm system is propelled by a strong southward dip in the jet stream punches into the Plains, Midwest and or south…
… This is accompanied by warm and humid air flowing northward out of the Gulf of Mexico.
The jet stream will provide deep wind shear and or changing wind speed and direction with height – supportive of rotating supercell thunderstorms.
If the wind shear strong in the first thousand feed near the surface, these supercell thunderstorms would more likely spawn Tornadoes.
Going on what has happened in the past, the greatest threat of Tornadic thunderstorms has shifted from the south into parts of the Plains and Midwest – migrates through April, May and June.
With that being said, we’re going to close this article. This post was inspired by The Weather Channel’s article which was posted several days ago – read here.