Author: Meteorologist Mark

Storms remain below severe limits as they cross portions of the plateau, but some of them sure are packing a punch. The folks at the Fentress County Fair can testify to that!

Remember that outflow boundary I showed in the last post? Well, it has certainly kicked off some storms. Some of the earlier storms have actually caught up with that boundary and it is certainly causing them to intensify a bit. One or two of these storms could become briefly severe.

Below is the current radar. Storms are slowly drifting southeast.

That outflow boundary and its interaction with the storms shows up quite well in animation!

Hopefully, some of us will get some good rain from this. Fingers crossed!

And don’t forget to look out for that lightning. Some of these storms are producing very frequent strikes!

Storms are now approaching the very western edge of the plateau. There is a very pronounced outflow boundary ahead of these storms, and I wouldn’t be a bit surprised if that boundary kicks off some storms as it approaches.

You can see it as that solid green line stretching across Middle TN in the image below. It is moving southeast, as are all the storms. That is a very pronounced outflow boundary. Those are quite common with remnants of big storm complexes.

It shows up really good in motion, if you can animate through the blog.

Outflow boundaries are like little cold fronts. The air behind them is rain-cooled from storm activity. As they push through, they force the air to rise, which can lead to shower and storm development. The reason they show up on radar as thin green lines is because radar is bouncing off all the humidity, dust, etc that these boundaries force upward into the atmosphere. It’s not necessarily raining when they pass through, even though radar looks like it is. As the gust front passes,  winds will become gusty and the temperature will drop a few degrees.

If the rain-cooled air is also cooled by hail, a huge temperature difference can result between the air ahead of behind the gust front. This can lead to destructive straight-line winds. Such is not the case today.

The severe threat continues to look low. We remain in the marginal risk for severe weather. I just noticed that the Storm Prediction Center has placed our entire region in the marginal risk for severe storms again tomorrow.

The Storm Prediction Center just issued a new update for our area (red-circled area). They stated that they do not anticipate issuing a severe t-storm watch for Middle TN or the plateau. This complex of storms that we’ve been tracking all day is moving our direction, for sure, but it is finally showing signs of disorganization and weakening. This will still increase our chance for showers and storms this evening, but the severe threat is looking lower.

You may notice the area of discussion for West TN. They are anticipated a severe t-storm watch to be issued for them, as storms move south. Notice those storms look more organized and intense than the ones coming our way.

Below is the current radar. Activity is moving south, southeast.

Storms will approach the western plateau within the next hour to hour and a half. One thing I have noticed is that many of these storms have slowed to a crawl. I could literally run faster than some of them are moving. Earlier today, storms were moving at 45-55 mph. Now, they’re down to 5-15 mph. Slower storms tend to signal weakening. That is good news! If these storms don’t pick up the pace, we may never see anything from them.

Outflows from these storms have been kicking off storms ahead of the line. We could easily see some storms pop up at any moment from these boundaries slipping south. Just keep an eye on your phone’s radar if you have outdoor plans this evening. Keep an eye out for lightning too. Right now, there’s not much around. Just keep an eye on that radar and lightning data.

I’ll keep an eye on things!