Severe WX April 3rd-5th, 2023 (South, Southeast, Ohio Valley)

[ColdFront]

Going to be an interesting few days leading up to this. The jet could theoretically speed up or shift in the coming days and “punch” into the open warm sector instead of graze it, correct?

 

[buckeye05]

The 18Z NAM EHI map almost looks like I imagine it would have for Palm Sunday 1965...large values extending from eastern Iowa across northern Illinois/far southern Wisconsin to northern IN and southwestern Lower MI. They don't extend quite as far east as the major activity did that day, but the overall pattern seems very similar.

Thoughts on Ohio? I’m wondering if the outlook area needs to be expanded eastward.

 

[jiharris0220]

I don’t fault Evan one bit. I actually have a hard time understanding why everyone is so hyped with this upcoming system.
Just looks like a whole bunch of capped, high LFC, modest shear garbage to me.
Every model shows basically f*#k all developing in the warm sector, and anything that does initiate goes linear almost instantly.
This can change of course, but as of now, definitely am not too on my toes like I was during the last event.

 

[CheeselandSkies]

I don’t fault Evan one bit. I actually have a hard time understanding why everyone is so hyped with this upcoming system.
Just looks like a whole bunch of capped, high LFC, modest shear garbage to me.
Every model shows basically f*#k all developing in the warm sector, and anything that does initiate goes linear almost instantly.
This can change of course, but as of now, definitely am not too on my toes like I was during the last event.

Sounding off the new GFS run for 21Z Tuesday in northwest IL.

Yes there is some capping there, but at 69/65 mixing/LCL certainly wouldn't be an issue. @andyhb

 

[Austin Dawg]

Remember a D3 MDT would be spanning all severe types, not just tornadoes.

We all forget other severe weather and focus on tornadoes for obvious and honest reasons. But when we experience a hail storm that is severe enough that it forces us to repair our roof, car, and truck, and then we might look at things differently and pay attention to other storms. I remember winds being severe enough at our other home to change the neighborhood's appearance. We experienced a downburst strong enough to fall several massive trees.

 

[ColdFront]

@andyhb or @Richardjacks could you elaborate a little more on what Evan was talking about with the 500 MB jet, and how it, not necessarily a failure mode, could dampen the northern threat into a more linear/wind driven threat?

 

[jiharris0220]

Meh, the LCL can be at the surface for all I care. It’s the LFC that actually matters, since thats the level where the air parcels does a free accent, basically where any potential updrafts would form. And that’s almost at 700mb, plus the fact that low level helicity is below 300 with shear barley at 40knots. A good majority of that stream wise vorticity will be lost.
Though that’s assuming that the LFC was even at an optimal height in the first place.
Lastly, that 6.0 low level lapse rate, while would be favorable in the Deep South, is pitiful up north, especially with that cap and high LFC.

 

[ColdFront]

Meh, the LCL can be at the surface for all I care. It’s the LFC that actually matters, since thats the level where the air parcels does a free accent, basically where any potential updrafts would form. And that’s almost at 700mb, plus the fact that low level helicity is below 300 with shear barley at 40knots. A good majority of that stream wise vorticity will be lost.
Though that’s assuming that the LFC was even at an optimal height in the first place.
Lastly, that 6.0 low level lapse rate, while would be favorable in the Deep South, is pitiful up north, especially with that cape and high LFC.

I think we are still a ways out though…

 

[jiharris0220]

I think we are still a ways out though…

I know, that’s why I mentioned in my last post that things can still change.
But there’s certainly no bullets coming out of my sweat on this one, at least for now.

 

[Donnie Beasley]

I don’t fault Evan one bit. I actually have a hard time understanding why everyone is so hyped with this upcoming system.
Just looks like a whole bunch of capped, high LFC, modest shear garbage to me.
Every model shows basically f*#k all developing in the warm sector, and anything that does initiate goes linear almost instantly.
This can change of course, but as of now, definitely am not too on my toes like I was during the last event.

Pretty bold take, but who knows you may end up being right. Just curious what models you are referring to as far as talking about storms not initiating? It hasn’t made it to any of the convective allowing models yet.

 

[jiharris0220]

Pretty bold take, but who knows you may end up being right. Just curious what models you are referring to as far as talking about storms not initiating? It hasn’t made it to any of the convective allowing models yet.

I was referring to warm sector initiation, which every global model and now even the nam shows nothing. The only initiation that takes place is near the cold front which everything is linear.
Plus even if discrete initiation occurred, the aforementioned factors I mentioned above would do in a lot of it.
However, like I said, things can change, for everyone’s sake concerning what just happened yesterday, for the better.

 

[ColdFront]

I was referring to warm sector initiation, which every global model and now even the nam shows nothing. The only initiation that takes place is near the cold front which everything is linear.
Plus even if discrete initiation occurred, the aforementioned factors I mentioned above would do in a lot of it.
However, like I said, things can change, for everyone’s sake concerning what just happened yesterday, for the better.

You’re just repeating Evan’s tweet Verbatim now…

Are you looking at composite reflectivity on the NAM?

I’m just curious On what model you’re using

 

[jiharris0220]

You’re just repeating Evan’s tweet Verbatim now…

Are you looking at composite reflectivity on the NAM?

How so?
All I’m saying is that I agree with him and that people shouldn’t be so quick to pull the trigger.
And yes I’m talking about the nam. Sure it does poorly with low level temps which would decrease instability. But that’s not the case this time. If anything it’s showing the most favorable environment because of less surface mixing.

 

[ColdFront]

How so?
All I’m saying is that I agree with him and that people shouldn’t be so quick to pull the trigger.
And yes I’m talking about the nam. Sure it does poorly with low level temps which would decrease instability. But that’s not the case this time. If anything it’s showing the most favorable environment because of less surface mixing.

Cool thanks for answering my question.

I think we will get a better idea on storm location/initiation better in the coming days as the CAMS come into range

 

[andyhb]

I don’t fault Evan one bit. I actually have a hard time understanding why everyone is so hyped with this upcoming system.
Just looks like a whole bunch of capped, high LFC, modest shear garbage to me.
Every model shows basically f*#k all developing in the warm sector, and anything that does initiate goes linear almost instantly.
This can change of course, but as of now, definitely am not too on my toes like I was during the last event.

A dryline staying uncapped for 6+ hours and not convecting is not something I'd hang my hat on.

 

[tennessee storm chaser]

How so?
All I’m saying is that I agree with him and that people shouldn’t be so quick to pull the trigger.
And yes I’m talking about the nam. Sure it does poorly with low level temps which would decrease instability. But that’s not the case this time. If anything it’s showing the most favorable environment because of less surface mixing.

whoa now... but i thought a top analog was april 3 1974?

 

[andyhb]

whoa now... but i thought a top analog was april 3 1974?

No, it isn't. A lot different than that when you're centered further west.

 

[CheeselandSkies]

Honestly for me the NAM/GFS still look like a go for the upper Midwest target (IA/IL). Similar to Friday, but with better curvature in the forecast hodographs (and that certainly wasn't an issue, lol). Doesn't need to be a Super Outbreak to be a dangerous day and/or great chase day.

 

[tennessee storm chaser]

They went with a day 3 enhanced.

 

[KevinH]

@Lake Martin EF4 you may want to update the thread title.

April 5th (D4) just got highlighted by the SPC