log in to manage your profile and account
- Create your account
- Receive up-to-date newsletters
- Set up text alerts
Published: Monday, May 20, 2019 @ 10:54 AM
— I’m sure by now you’ve heard all about the tornado that occurred Sunday near West Alexandria. Many of you have asked me why there were no tornado watches or warnings issued. In order to answer that I need to explain the basics.
We are no strangers to the terms watches and warnings, but do you really know who issues them?
First off, let me start by saying neither a watch or a warning is ever issued by any television station, in any city or state across the country, including WHIO-TV. And issuing a watch or warning may not be as easy as one would think. There can be a lot to consider before issuing one, including the concern of not over-warning. That could eventually lead to false alarms and distrust by the public.
SEE THE DAMAGE: Huber Heights hit hard by Sunday storms
When it comes to issuing the initial watch, the Storm Prediction Center (SPC) located in Norman, Okla. is the one to determine which counties will be included. Of course, they are not the only decision-makers in the process.
The SPC will communicate with the local National Weather Service — and for us that is the Wilmington office — before pulling the trigger. Once the watch has been issued, it’s up to the local office to expand it or cancel it when deemed necessary. If there is a need for a storm to be warned, that is up to the local National Weather Service.
So what happened this weekend?
A widespread batch of heavy rain and gusty winds moved through the Miami Valley during the early afternoon hours on Sunday. Once this batch of rain cleared the area, warming and destabilization of the environment once again increased. It was a classic wait-and-see as to whether conditions would favor another round of storms.
Shortly before 8:30 pm Sunday, a line of strong-to-severe thunderstorms were approaching the western border of Preble County. The NWS in Wilmington issued a severe thunderstorm warning with the potential of thunderstorm wind gusts to reach 60 mph. Due to the linear nature of these storms, there was no immediate threat for tornadoes.
As the line entered the county, it began to bow and break.
If atmospheric conditions are favorable (and they were), the segmenting of a line of storms like this can cause a brief spin-up tornado. The term for this type of tornado is QLCS (Quasi-linear Convective System). Unfortunately, QLCS storms tend to be brief and hard to detect.
Because of the brief nature of this particular QLCS tornado, no warning was never issued. It’s also important to note that by the time reports of damage had been received, the tornado had already dissipated.
This is why all warnings should never be taken lightly. The severe thunderstorm warning issued on Sunday for Preble County likely helped to get people indoors and away from the severe conditions outside.