Monday, March 15, 2010

The Tornado With No Warning

After the tornadoes last Wednesday, pictures and damage reports trickled in for a couple of days. One picture was from Jim's Rental in Doniphan, MO. As you can see, it sustained major damage. It took a few days for the damage to be surveyed and when the NWS did survey it on Saturday, they concluded that it was damage from an EF1 tornado. The full report can be found here. Here's the problem... there was no warning. No tornado warning and no severe thunderstorm warning. (See the stats from IEM COW here) Let's analyze and begin with a radar loop from 11:20 PM to 11:38PM Wednesday night:
If you notice in the radar loop, a decent storm was moving through the Doniphan area. It was part of a squall line and the nature of the entire line had lost the characteristics of most tornadic environments. While we were on air doing a cut-in (as stated in the previous blog), we did not detect a tornado. Since there was no warning, I assume the NWS didn't either. It's much easier to go back and see the signs; and that's what I've been doing this evening. While the signs were tiny, they were there. The first sign is seen in the reflectivity loop above. When the storm is over Doniphan, do you see the area where the "red" is broken up by "orange"? It's subtle, but there's a little "break" in the line. We call that a Bounded Weak Echo Region or BWER. That's sign #1... Let's go to the velocity (wind) loop:
Once again, it's much easier playing Monday Morning Quarterback on severe weather, but in the velocity loop, we can see the tornado. It's VERY subtle, but notice the bright shades of green moving from SW to NE and passes 2 miles SE of Doniphan. That's our tornado and sign #2.

If given the same scenerio next year, many of us would still miss it. It's that subtle. Let's move on to some still images. This first velocity image is from 11:20 PM, 10 minutes before it touched down. Notice the start of the rotation and the mesocyclone:
That area moves NE and a tornado touches down 2 miles SE of Doniphan with winds of 100 mph. In the below image, there are some signs, but they are so teeny, tiny that it went
undetected and unwarned.
While it is not good to have a tornado without warning, we can't put blame on anyone. The signs of this tornado were small and the situational awareness of tornadic storms had gone way down. The folks at the NWS bust their tail to do their best at issuing warnings, but this storm was 90-100 miles from their radar sites. Radar distance was the main disadvantage on this particular storm. We need a radar in Southern Missouri!

Anywho, I'm going to sleep. Take care.


Andrew said...

I must say Ryan if I had to make a call of there being a tornado or not I would have to say no. We all know different now due to the damage but not every single tornado will always be caught by the human eyes that spend so much time looking for them during storms. Like you said there is no one to blame, this is just one of those things that happen and I am sure it will happen again somewhere in the US this year.

IceDown said...

I was watching that storm. I seen it surge for a few and wondered if that was happening. I was mobile so lvl3 data was all I had but I would have probably wrote that off as artifact as well. That's the problem when the lowest radar sweep is at ~10k ft.

Heidi said...

We need a radar in Southern Missouri!

A West Plains radar would have been all over that. And the one near Gainesville. It seems like Gainesville gets one almost every year that was either not warned or warned too late.