Sunday afternoon around 3:00PM a tornado spun up in Dunklin county just west of the intersection of HWY 102 and HWY 25 north of Malden.
Tornadoes usually form with rotation severe thunderstorms
and usually have a few minutes warning time before they develop. But there is one type of tornado that usually
develops quickly and without warning.
That type of tornado is called the landspout. A landspout tornado forms much in the same
way its cousin the waterspout develops over the water. Instead of a rotating severe thunderstorm in
which rotation form the mid levels is brought down to the surface, these tornadoes
start as a swirl on the ground that is stretched under a storm’s updraft.
Two dust swirls on the ground. Photo Leslie Asher.
Sunday afternoon there was a thundershower located over
Dunklin County that collapsed around 2:40PM sending a boundary of rain cooled
air across the Bootheel. Along and immediately
behind this boundary little eddies or swirls form. Picture your arm moving along the top of the
water in a swimming pool. Right behind
your arm you will see little swirls form.
This same action occurs in the atmosphere as boundaries move
through.
Video above from Brandon Shelton.
As the boundary approached Malden a thundershower was
rapidly developing. This thundershower’s
updraft encountered the swirls on the ground stretching them making the
rotation stronger. The stretched
rotation is pulled into the thundershower’s updraft and a tornado forms.
Dust Swirl stretched into the storm. Photo Leslie Asher.
Now landspouts are usually very weak, EF0, but in some cases
have reached EF3 strength depending on the storm’s updraft strength. Looking at the video seen these were very
weak, maybe technically not reaching the 65MPH wind speed needed to be classified
as an EF0 tornado. But with that said
anytime there is a rotating column of air in contact with a storms updraft by
definition, it’s a tornado. Not sure if
this will go down as an official tornado but to all who sent video and photos
to help me investigate, thanks. You can
tell all your family and friends you saw a tornado.
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