Yes, there was a tornado.
And, in this case, the video probably really helped the National weather Service identify it. The NWS in Jackson has rated this an EF-0 tornado that was on the ground for a very short period of time.
But I want to help clear up some confusion (for those who have questions). So I went through and clipped a few of the questions people have been asking during the last 24 hours and I want to try to answer them here.
“It isn’t tornado season! How did this happen?”
This was quite the lottery ticket of an event. As I mentioned in a facebook post yesterday, I tend to think that historically meaningful (albeit low) 1KM helicity with super low LCLs laid across a boundary in place while a line of storms moved overhead (sort of) perpendicular to the boundary likely led to the chance for a brief tornado to develop. But it wasn’t very cut-and-dry.
This is the type of thing that is a bit ‘unforecastable’ because it really does depend on a lot of things to line up in the right way at the right time and in the right direction.
Imagine riding in the back of a pickup holding a football. And they say, “throw it through that target!” and the target is a swinging tire, in the back of another pickup driving away from you. And the football is weighted heavier on one side than the other, and you’re doing it during an earthquake.
That would be tough! And even if you tried 100 times, you may not hit your target more than once or twice.
That is what this was like. A lot of moving parts and the chance we could get this to happen again, given the same situation is pretty low.
“Why wasn’t there a Tornado Warning? Or a Severe Thunderstorm Watch?”
This was one of those very-low probability events that is, basically, unforecastable. The convergence of a few boundaries just happened to occur underneath a thunderstorm where an updraft was rooted and there was sufficient stretching and turning in the low-levels to basically ‘squeeze out’ a tornado.
This developed and dissipated in a region of the atmosphere that the radar can’t see, on a timescale that even higher-resolution models can’t predict, and across a geographic area that modeling can’t resolve.
I wish I had a better answer, but we are only so good.
And by the time reports of the tornado and videos of the event were sent to the NWS and radar operators, the storms moved off of the intersecting boundaries and was no longer a threat to produce a tornado.
There wasn’t a Warning nor a Watch issued because the general threat for severe weather and tornadoes was too low. Instead, Flash flood Warnings were in effect for much of the area as flooding was going to be the main threat yesterday.
“Some people are calling it a gustnado, you said may even be a landspout, but I saw it. It was a tornado! What gives?”
There are a few different types of spinning things that happen near thunderstorms. And depending on what the catalyst for the spinning is, dictates what we (meteorologists) classify it as.
— A gustnado is often a ground-level vortex of air that is caused by intersecting outflow boundaries. Something called a “gust front” is often kicked out by more organized thunderstorms (not just the typical summertime storms). As these gust fronts move away from the storm, they can interact with the air that is already hanging around. And if the air that is already there is moving one way and the gust front is moving in another way it can briefly spin up a vortex near the ground that has no relationship to what is happening above it or in the clouds. That is why it isn’t a tornado.
And that is why, I would argue, it doesn’t apply here.
— A landspout, a bit like a waterspout, is based on what is happening in the lowest level of the storm and at the cloud base and beneath it. According to the NWS glossary, a landspout is a tornado that does not arise from organized storm-scale rotation and therefore is not associated with a wall cloud (visually) or a mesocyclone (on radar). The idea here is that the storm isn’t rotating, nothing is really rotating, but you still end up with enough torque and spin within the air column under the clouds to get a visible vortex to develop.
This is why i suggested it as a potential originally. The only videos I received showed no real rotation in the based of the clouds and no wall cloud. Instead it was a lot of rotation beneath the cloud based with a bit of a condensation tube.
Differentiating between a tornado and a landspout doesn’t take a meteorology degree by any means. But it does take a trained eye – even if that’s just from experience of seeing both a handful of different times in different situations.
And knowing that this occurred along two intersecting boundaries under the storm already in place, I surmised that there likely wasn’t enough spin within the storm (as evidenced on radar) for it to be a true tornado. But I didn’t have enough evidence at the time to say ‘yay’ or ‘nay’ and I said I would wait for the NWS to make their determination.
— A tornado is a rotating column of air that is directly associated with rotation within the cloud and/or storm that is relfected with a vortex that is in contact with the ground.
The reason the NWS went with calling it a tornado is because there was very, very brief rotation on radar at the lowest level of the scans (around 6,000ft) as well as ample video showing rotating clouds at the lowest level with – what could be called – a wall cloud and a weakly rotating funnel. At ground level there was a stronger rotation that was connected to that broader rotation at the cloud base.
I would tend to agree with the NWS assessment here. Originally (even as early as this morning!) I was still thinking landspout. But then i was able to watch some extra video (sent in by a lot of you!) that helped by ID the rotation at the base of the cloud level as well as a look at the radar imagery from the time showing that very brief broad rotation.
In fact! This is why we really need to give the NWS time to survey events after they happen. I know our knee-jerk reaction is to ask for answers quickly, but with Science, sometimes it takes time to shake out the answer.
Other notes…
— Keep in mind that the NWS folks are doing the best they can to keep everyone safe during our crazy weather. Sometimes things happen quickly and then end just as fast before anyone — including the NWS — can react. It doesn’t happen often, but it does happen.
— Tornadoes can look drastically different based on what side of the storm you are located. And no one can know how strong or big a tornado is just by looking at it from a distance. In order to make certain we know exactly how strong the tornado is, we need to wait and see what damage it causes and we can’t assess that until after the storm has passed.
— I understand how scary it may feel for some folks to hear that things may happen quickly and we can’t know about a tornado until it causes damage. But I want to really stress here that any tornado that forms and dies this quickly is unlikely to be strong or devastating at all. Often these torandoes are just strong enough to break tree branches, knock down fences and cause some shingle damage. They can’t lift homes off their foundations nor roll anchored Mobile Homes.
