A Late Look At Late Data From AdvanceTrak For Severe Weather Potential Early Wednesday!

I wanted to give you a late update on the severe weather potential for early Wednesday. Since this will only be a supplemental update, I want to encourage you to read my previous blog for a full discussion on the severe weather potential early Wednesday...

 

http://fox41blogs.typepad.com/wdrb_weather/2013/01/severe-weather-risk-for-wednesday-morning-my-thoughts-in-this-blog.html

 

Late Data Regarding Wednesday Morning

 

As you look at AdvanceTrak, keep in mind the time stamp is on the top right part of each image. Notice the intensity of the line per AdvanceTrak early Wednesday. Notice the distinct breaks in the line at 7:30 am. Remember breaks in the line equal the potential for spin-ups. Please do not focus in the exact location of the break in the line, but only that they exist. Computer models do not have the ability to forecast accurately where these breaks will occur.

 

 

 

 

 

 

 

 

My Thoughts...

 

Just a few notes regarding the late NAM. It has increased instability area-wide as I said it should in my blog earlier today. The NAM is now showing a temperature of 64 early Thursday with an instability now at 582 units for Louisville. Notice the higher instability values approaching 1000 units in the southern part of our area early Wednesday on the latest NAM. This is concerning.

 

 

The wind energy remains brutally strong as the latest run of the NAM shows about 70 knot or 80 mph winds just 1 mile above the ground early Thursday. I think the instability is more than enough to support severe weather on Wednesday morning and the latest data makes a convincing argument to support my forecast.

 

 

Here is a refresh of my thoughts from my blog earlier tonight...

 

The bottom line is that a major upper level low moving across our area Wednesday morning with a powerful front that moves through during the afternoon on Wednesday. This will create intense rising motion and forcing is more than sufficient for severe weather. The wind energy is simply brutally strong. The winds increase to near 90 - 100 mph just a mile above the ground early Wednesday which is just incredible. The winds do change direction with height and we have the more dangerous directional wind shear. The instability is low but unquestionably there. I also think the computer models are underestimating the instability Wednesday morning and that could be a problem. I would not be surprised to see up to 750 units of instability early Wednesday. In my opinion, we will see severe weather in our area early Wednesday.

The wind energy is really exceptional early Wednesday and we have "directional wind shear" Remember directional wind shear is the type of wind energy that can and does produce tornadoes. The instability is being underestimated by the computer models in my opinion and this means we have a mix of powerful wind shear and lower level instability. The NAM suggests there is a very good chance that we will see some rotating storms in our area. The NAM supercell index shows us the likelihood of rotating storms and you can see the values are high in our area and VERY high over TN/AR/MS.

 

 

All of the data has me concerned. I think we will see a lot of damaging wind reports early Wednesday and I wouldn't rule out destructive winds over 70 mph. The line of storms will definitely have breaks in it based on the profile in the atmosphere and these breaks in the line can produce tornadoes. The main threat will be damaging winds (I cannot rule out some destructive winds) and isolated tornadoes. The wind energy absolutely supports all modes of severe weather, but the instability will be the key in determining how bad it gets. I absolutely think the entire area should be under a slight risk of severe weather. This is a storm that we need to watch and this could be an outbreak of severe weather. We will be watching this one VERY closely.

 

 

 

 

 

If you ever have any questions, please remember I can be reached on facebook easily! Just follow the link below to my facebook page and click "LIKE"!

https://www.facebook.com/pages/Marc-Weinberg/171330336238674#!/pages/Marc-Weinberg/171330336238674

 

Comments

[Kyldy11]

hi marc do this mean that radcliff will get torndoas?

[Marc Weinberg]

Kyldy11, this does not equal a tornado for any specific community. It means damaging to destructive winds are the primary threat and isolated tornadoes could occur.

[John]

Marc, to be honest, I have not heard you this concerned since your blog 2 days before the Mar 2 outbreak. I will never forget that blog. Was watching UofL throw in a clunker on the tube and was so annoyed and read your blog and lost focus on the game and could not believe what I was reading from you because a lot of times you tell everyone to cheer but the hype was legit then, we all know what happened. Not quite as dramatic here but I will say darn close. I was assuming timing of this would kill instability but according to you this is one of those rare times

[Kyldy11]

i notice the line breaks as it comes through radcliff.thank you so much for being there.

[Marc Weinberg]

John, there is absolutely no comparison to March 2nd. That was a once in a generation storm and this is not. With that said, this is a legit concern for damaging and possible destructive winds with isolated tornadoes. The parameters appear to be setting up for widespread severe weather. The higher the instability tomorrow night, the greater the chance of tornadoes.

[Ryan]

Thanks Marc, partially agree with post by "John" that this might be the most concerned you have been since the 3/2/12 outbreak, but I don't think you "cheer" for severe weather. I'll be following on twitter for updates throughout tomorrow night!

[James Lewis Olin]

I wonder what was the instability value for Henryville on March 2nd when we had the EF-4 tornado and 2 other tornado(s) I know there where 3 at least I saw the third one form Just west of Snow Road and go east doing damage just west of Zollman Road.

[John Brooks]

It's getting to be that time of year again. We seem to get 1 or 2 big severe weather days during the winter every year. Just a preview of the rest of the year I guess

[James Lewis Olin]

That is NORTH of Zollman Road damage; The EF-4 destroyed my son's house on Brownstown Road; the second tornado brought the hail up to a softball in diameter and larger.

[Marc Weinberg]

James, all of that data is archived in my blogs from those days. They were way higher and the significant tornado parameters were absolutely pegged!

[James Lewis Olin]

Thanks . I'll be watching for your up dates.