NWS And Today’s Chilton County Storm

A small, EF0 tornado touched down in Chilton County very briefly late this morning north of Clanton. There was no warning for this tornado by the National Weather Service, and I wanted to take a minute here and defend them.

*This small spin-up was in a tropical rain band, much like the spiral bands we experience with a tropical storm that has moved inland from the Gulf. In today’s case, the low (both at the surface and aloft) is west of Alabama, around Shreveport, and although it was never a tropical storm, or even a tropical depression, the impact is very similar.

*Trying to warn for spin-up tornadoes in tropical rain bands is almost impossible for a number of reasons; the tops of the showers are very low, and in most cases the rotation is below the radar beam, and the rotation comes and goes in a heartbeat. Even if you get a report of a tornado like today, by the time you get a warning issued the thing is gone.

*If you wind up issuing a tornado warning for every hint of rotation within a tropical rain band, you will wind up with false warnings a very high percentage of the time. And, the more false warnings, the more people will ignore tornado warnings. It doesn’t make sense to issue ramp up the FAR (false alarm ratio) trying to catch one small spin-up. That can destroy the warning system.

You can have the same set-up dozens of times, and there won’t be a warning. Just too hard. I firmly believe humility is one of the greatest things missing in our science… there are some things we can do, and there some things we can’t do. Providing a warning for every EF0 tornado in a tropical shower just can’t be done right now….

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