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Tornadus Interuptus

Posted at 10:42 PM, Nov 06, 2018

There is usually an uptick in severe weather during the latter half of the fall season.  It’s not as dramatic or as active as the spring transition, but it’s there nonetheless.  The vigorous spring season occurs as we are transitioning from the cold season to the warm.  The upper air is slower to shake off the cold of winter, so warm intrusions can create a greater instability (stronger fuel).

In the autumn, the differences are not as pronounced, and in fact there are times like last night where there wasn’t a ton of instability, but there was a lot of shear provided by the seasonally strengthening jet stream which adds its own twist to the severe weather equation.

If you were trying to watch the Tonight Show last night, well you basically couldn’t because we were in our ‘wall to wall’ coverage that is our mandate during Tornado Warnings.  Every large company has a protocol during severe weather or emergency situations, that is ours.  It’s to get the information to everyone in the endangered counties so they can remain as safe as possible.  The difficulty arises as we can’t assume everyone who needs the info is watching us from the beginning, so it does essentially evolve into a play by play as new people join in the coverage.

Monday night was a well advertised event as we began talking about it the middle of last week.  The squall line did form and we did have 2 confirmed tornadoes in what is considered our western ‘fringe’ area, Adair and Marion counties.

Tornado reports
2 Confirmed Tornadoes Monday

These tornadoes occurred within 10 minutes of each other within the same squall line.  They both presented well on the MaxTrack Doppler radar with velocity couplets (wind moving different directions) next to each other.  These were in association with a fast moving squall line…about 50 mph…so they were covering a lot of real estate.  The thing is with the Doppler, in most cases it’s impossible to tell the exact minute if or when a rotation aloft is going to come down so the warnings have a half hour or so of time which if you do the math is about 25 to 30 miles as the crow flies.  The warnings for Adair and Marion counties extended into counties that we are directly responsible for, Boyle and Casey…and thus the wall to wall coverage.  By the way, the rotation continued to present itself nicely well into Casey County.  The Marion County storm did lose its signature more quickly.

So the bottom line is we did almost an hour of coverage for 2 very short lived storms.  The Adair County storm was on the ground for about 4 minutes with winds around 100 mph.  The Marion County storm only lasted about 2 minutes with winds in the 85 mph range..  That warning was discontinued before its natural expiration time.  The other thing is we also can’t really tell from the radar the strength of a tornado.  You can’t look at a couplet and go, “Why that’s an EF-2 spinning right there”.  You have to assume that every tornado is dangerous.  The numbers are assigned the day after by trained damage survey teams.

There were also a few other damage reports mainly from northern Jessamine and southern Fayette counties.  These were straight line wind events.  The damage pattern in the tornadic storm is chaotic, stuff goes all directions.  With the straight line winds, everything falls one way, and in this case a 200 year old oak tree came down.  Damage from wind going straight can be just as severe as winds spinning in a circle.

It is about safety.  It’s not because we want to ‘show off our radar’ or we’ve got nothing better to do.  Believe me, we’d love to never do a wall to wall cut in again.  But when potentially life saving information is being given out…and it can be…well then you can see the importance and why we do what we do.

So hopefully that reveals a little of the thinking back here.  We do know you want to watch your programs, and we do know that the storms may have been no where near you.  But the next time, it may be your county that is under the gun.

Now enjoy your Wednesday and be prepared for the onslaught of the cold season.

 

Bill Meck