Severe Weather Threat - May 6, 2024

[Casuarina Head]

This is what this forum is meant to be for: top-notch meteorological learning!

 

[Fred Gossage]

So the type of CIN you’re talking about would be something like this.

Where a warm nose near the surface pushes the LFC upwards which keeps storms from being surfaced base, if they don’t develop before it sets in.
View attachment 26318

Exactly right. That's the difference between the two. And this above is what would've been being modeled in the maps on that original tweet that started our discussion.

 

[jiharris0220]

Exactly right. That's the difference between the two. And this above is what would've been being modeled in the maps on that original tweet that started our discussion.

I completely get you now, thank you for taking the time to explain your point. This will surely help a lot of people who pass through this thread understand.

 

[warneagle]

Fred, I know you’re a busy man, but I’d watch you lecture or comment on the “x’s and o’s” of meteorology in some kind of YouTube video series any day.

There’s a really good series of videos on YouTube from the OU School of Meteorology where Rich Thompson from the SPC walks through a lot of the basics of interpreting forecast maps/soundings/etc. and applying those to forecasting severe weather that would probably be just what you’re looking for.

 

[Fred Gossage]

I completely get you now, thank you for taking the time to explain your point. This will surely help a lot of people who pass through this thread understand.

The one thing I will note about the above example you posted though is that the LFC would actually be lower in the atmosphere there than in the EML capping case, because of the inversion here being lower in the atmosphere than with an EML/cap inversion. The difference between those is that there are still steep lapse rates and potential rising motion and even CAPE building below that EML/cap inversion. There is not with the nocturnal inversion.

 

[Tempestas Tonitrua]

There’s a really good series of videos on YouTube from the OU School of Meteorology where Rich Thompson from the SPC walks through a lot of the basics of interpreting forecast maps/soundings/etc. and applying those to forecasting severe weather that would probably be just what you’re looking for.

That’s actually awesome you watched that same series too, I posted about it this morning on the severe weather 20204 thread. I found it it incredible

 

[andyhb]

18z HRRR... mother of god.

 

[TornadoFan]

 

[Maxis_s]

...oh no.

 

[TornadoFan]

That STP. WTF.

 

[Tempestas Tonitrua]

...oh no.

View attachment 26319View attachment 26322

Wow. If any storms go up in that extreme in environment Central/Southern OK…

 

[Maxis_s]

Wow. If any storms go up in that extreme environment Central/Southern OK…

Random sounding in the area. Only issue is an inversion at the surface, which may not be that much of a limiting factor.

 

[Fred Gossage]

18z HRRR... mother of god.

From everything I see, limited number of storms in the discrete mode area looks to be the only potential thing that would get SPC to hold off on pulling the trigger for a High Risk. This is a significantly meaner looking parameter space than what was modeled ahead of time for last Saturday's threat. While there may not be as many storms, I do think there is a greater EF4+ threat (possibly significantly so) than the Oklahoma event last Saturday. I think that if there is any trend toward confidence in a few more storms than is being modeled in that HRRR run, they will pull the trigger.

 

[tennessee storm chaser]

From everything I see, limited number of storms in the discrete mode area looks to be the only potential thing that would get SPC to hold off on pulling the trigger for a High Risk. This is a significantly meaner looking parameter space than what was modeled ahead of time for last Saturday's threat. While there may not be as many storms, I do think there is a greater EF4+ threat (possibly significantly so) than the Oklahoma event last Saturday. I think that if there is any trend toward confidence in a few more storms than is being modeled in that HRRR run, they will pull the trigger.

Yeah that spacing parameter is very concerning …. If correct

 

[andyhb]

From everything I see, limited number of storms in the discrete mode area looks to be the only potential thing that would get SPC to hold off on pulling the trigger for a High Risk. This is a significantly meaner looking parameter space than what was modeled ahead of time for last Saturday's threat. While there may not be as many storms, I do think there is a greater EF4+ threat (possibly significantly so) than the Oklahoma event last Saturday. I think that if there is any trend toward confidence in a few more storms than is being modeled in that HRRR run, they will pull the trigger.

Should add that a number of the semi-discrete cells in KS have moderate to strong low level UH modelled. I don't think this would just be an OK problem. That major long tracked cell in OK goes right through Stillwater and parts of the Tulsa metro.

 

[Tempestas Tonitrua]

From everything I see, limited number of storms in the discrete mode area looks to be the only potential thing that would get SPC to hold off on pulling the trigger for a High Risk. This is a significantly meaner looking parameter space than what was modeled ahead of time for last Saturday's threat. While there may not be as many storms, I do think there is a greater EF4+ threat (possibly significantly so) than the Oklahoma event last Saturday. I think that if there is any trend toward confidence in a few more storms than is being modeled in that HRRR run, they will pull the trigger.

I was about to add, it seems the 18z HRRR run showed a lack of discrete development in the more “rich” environment down south with plenty up north in Kansas and Northern Oklahoma. Will it be mesoscale factors that fire storms off in that southern area?

 

[Fred Gossage]

Yeah that spacing parameter is very concerning …. If correct

A high-end parameter space has been modeled in the global models for a full week out, if not more. This environmental look has been consistent. It's always been a question of forcing and storm mode. There's zero reason to believe the parameter space being modeled isn't at least pretty close to what ends up verifying.

 

[Fred Gossage]

I was about to add, it seems the 18z HRRR run showed a lack of discrete development in the more “rich” environment down south with plenty up north in Kansas and Northern Oklahoma. Will it be mesoscale factors that fire storms off in that southern area?

South of I-40, it seems to be a combination of capping and better height falls being north of the area. We'll see how much of that actually plays out.

 

[TH2002]

Hoo boy... when the usually conservative GFS model is spitting out forecasted soundings like this, you know things could get really bad.
*First is from the OKC metro, second is from north central OK in the path of that long-tracker the HRRR spawns

 

[Fred Gossage]

Should add that a number of the semi-discrete cells in KS have moderate to strong low level UH modelled. I don't think this would just be an OK problem. That major long tracked cell in OK goes right through Stillwater and parts of the Tulsa metro.

You're definitely right. It's just that the more clean-cut, clear violent tornado threat is Oklahoma into far southern Kansas.