Any Severe Weather Risk Today???

This has been an unusually busy week for the fall. We have had threats of severe weather every single day this work week leading into our Thursday. The front responsible for those storms is still drapped across our area, so I wanted to discuss the potential for it to produce severe weather this afternoon / evening.

 

 

SPC Severe Weather Risk Today/Tonight

 

For the first day this week, SPC does not have any of our area in a slight risk of severe weather. With that said, they do have some severe weather probabilities for our area.

 

SPC Categorical Risk Of Severe Weather Today/Tonight

Notice you don't see any slight risk for our area... just the general t-storm risk.

 

 

SPC Hail Risk Today/Tonight

Notice SPC does have a 5% chance of hail for any storms that fire late today / tonight.

 

 

SPC Damaging Wind Risk Today/Tonight

Notice SPC also has a 5% chance of damaging winds in our area

 

 

SPC Tornado Risk Today/Tonight

Notice SPC has no tornado risk for our area.

 

 

 

Severe Weather Discussion

 

As we dive into the discussion about severe weather potential today, I want to remind you of the ingredients I look for when I forecast organized severe weather risks.

 

 

Forcing

We still have a front in our area, so forcing is available to generate storms this afternoon. This doesn't mean they will be severe, but it does mean some storms will fire. We have a little action right now along the front just south of Louisville.

 

 

Instability

 

The instability this afternoon is quite frankly not very good. Much of that is caused by the nagging cloud cover we have seen all afternoon long. Most of the instability values in our area are from 500 - 1000 units.

 

 

Wind Energy

If you are a regular to my blog, then you know I look for wind energy at 6 miles above the ground at or above 35 knots or 40 mph to support an organized severe weather threat. This wind is crucial because it allows storms to evacuate much of the air and rain that rise into the updraft. If the storm cannot evacuate some of the mass it collects as the air rises, then the updraft simply cannot sustain the weight of the updraft and the storm collapses. When you look at the winds 6 miles above the ground the afternoon, you see most of the flow is 25 - 30 knots / 28 - 34 mph. While there may be a touch of winds that are a bit higher to our west, it appears it will decrease after sunset.

 

My Thoughts On Severe Weather Tonight

 

The data shows weakness in the instability and wind energy fields this evening. Sometimes if either the instability or wind energy is just absurdly high it can make up for a weakness in the other field. Both of these key fields are weak today and that means the threat of organized severe weather is low. I agree with SPC not placing our area in a slight risk of severe and I see the threat as low. While an isolated warning can never be ruled out, this is not an event ... period.

 

AdvanceTrak shows the scattered nature of the showers / t-storms tonight. Notice you just don't see a lot of red or purples indicating the cores are just not very strong.

 

 

 

 

I will watch the setup closely regardless and have updates as necessary.

 

 

 

 

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

[L. S. Phillips]

Good evening, Marc. I was just thinking today about how this is the wonderful season called autumn. Then, I wondered, "Will the drought from the summer have a negative affect on the chances that we'll see beautiful fall foliage?" I think it will, but I am not sure, scientifically, why that would be correct. We're seeing all those rainfall totals in fall now. Will that make a difference for the foliage too?

[L. S. Phillips]

Oops. typo *affect should be effect* in my prior post.

[Marc Weinberg]

The foliage this year will absolutely be affected by the drought. The rain is just too late to affect the fall colors. It should not be the best year for foliage unfortunately. :(

[L. S. Phillips]

Oh, I had a feeling the rain was too late to have a therapeutic effect on those poor, stressed-out trees. :o(

Would you consider composing a blog, sometime this fall, to explain the reason the drought will have that effect on the trees? You're articulate when explaining the science of meteorology.

[Marc Weinberg]

Lisa, I already have the blog written. :)

http://fox41blogs.typepad.com/wdrb_weather/2011/09/change-of-pace-today-lets-talk-fall-foliage.html

[L. S. Phillips]

Wow, that was fast! You work so efficiently. :o)

The drought will cause the leaves to be less "brilliant." Gee, I didn't know the leaves are smarter when there is no drought. LOL!

Thank you, Marc.