Severe Weather 2025

[joshoctober16]

I found this really cool resource with soundings from basically every major severe weather event of the last 25 years. Some (probably obvious) trends I'm noticing are dry air aloft in the 700-500 mb range and high CAPE makes SRH less important. Likewise, CAPE is less important when helicity and sheer are really high (3-14/15 comes to mind). Strong tornadoes also seem to be pretty rare when effective sheer is outside the 40-80kt range.

[Retired] Case Archive - ustornadoes.com

Soundings, hodographs, and much more. Case synopses on some of the most well known U.S. tornadoes of the 2000s. Over 200 events examined.

www.ustornadoes.com

im starting to wonder if there should be a thread about parameters where we share are ideas on stuff like this.

we could find some Forecasted Convective Amplification Deficiency issues and surprise boom moments from looking at parameters that others haven't look into before.

recently I've been noticing hybrid tornadoes tend to form in a type of environment.
also notice that a lot of the high risk Forecasted Convective Amplification Deficiency Oklahoma events have the same mlcape vs dcape issues.

if there is 2 things I'm noticing for tornado research is.
1:they seem to completely ignore moister / wet / dry part of the environment.
2: Dcape seems to be completely ignored however base on the nudger theory it would seem like this would be very important.

 

[Grand Poo Bah]

im starting to wonder if there should be a thread about parameters where we share are ideas on stuff like this.

we could find some Forecasted Convective Amplification Deficiency issues and surprise boom moments from looking at parameters that others haven't look into before.

recently I've been noticing hybrid tornadoes tend to form in a type of environment.
also notice that a lot of the high risk Forecasted Convective Amplification Deficiency Oklahoma events have the same mlcape vs dcape issues.

if there is 2 things I'm noticing for tornado research is.
1:they seem to completely ignore moister / wet / dry part of the environment.
2: Dcape seems to be completely ignored however base on the nudger theory it would seem like this would be very important.

I've been thinking a "Weather Science" thread would be great to have. This would definitely fit under the science umbrella too.

 

[Grand Poo Bah]

GFS is concerning again! Fully acting up with what looks like a widespread outbreak of very large hail and strong tornadoes Tuesday evening through Thursday, IF storms even initiate. Models aren't showing it currently. Even the supercell composite is pretty modest.



These are soundings from NINE different states. Pretty bonkers.

 

[N0mz]

I agree lots of good ingredients here but the cap, if it stays as forecasted, will probably limit the potential on the 14-15th

GFS is concerning again! Fully acting up with what looks like a widespread outbreak of very large hail and strong tornadoes Tuesday evening through Thursday, IF storms even initiate. Models aren't showing it currently. Even the supercell composite is pretty modest.

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These are soundings from NINE different states. Pretty bonkers.

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[Grand Poo Bah]

I think I found what's going on.

Here's a gif of humidity on the ground. Notice the dryline up North pushing South. With another West to East dryline over Kansas fighting for its life.



10,000 feet up is a different story. See the very thin dry band starting over TX/OK and moving East to IN/TN. The Kansas and northern drylines shove it and warp it while also creating pockets of wet and dry air moving rapidly in succession, which is why the models are showing so many waves. It's like a conga line of dry lines.



18,000 feet up it's even more pronounced. A big note is how each level of the atmosphere has drastically different wind directions too.




It's worth noting the Euro is showing the exact same thing, except with way more defined drylines across the board and complete 360 degree rotations of wind directions along it. This is materializing into some pretty crazy soundings from Nebraska to Wisconsin to Kentucky,



top analog is 6 inch hail lol

 

[Grand Poo Bah]

CIPS and CSU are both starting to pick up on it as well.

 

[CheeselandSkies]

Not getting too excited/concerned at this stage, but SPC does hint at some potential into this region in about a week.

Toward next Thursday/Friday, there does appear consensus that
stronger destabilization may begin to become better coupled with
large-scale forcing for ascent across the upper Mississippi
Valley/Midwest into Ohio Valley, as the mid-level troughing
progresses northeastward and eastward, around the periphery of
mid/upper ridging building north-northeast of the lower Mississippi
Valley. This appears to include at least a conditional risk for
organized severe convection, including a few supercells. Although
lingering uncertainties preclude introducing 15 percent or greater
severe probabilities at this time, this may change in later outlooks
for this period.

..Kerr.. 05/09/2025

 

[MichelleH]

It can definitely happen, but historically has been fairly rare. We fairly often will get some of the leftovers of Plains events, but those are usually relatively low-end. Granted, I would much rather May outbreaks remain rare in the Deep South, don't really wanna see what May thermos can do.

May 27, 1973. That's what they can do.

 

[Tennie]

im starting to wonder if there should be a thread about parameters where we share are ideas on stuff like this.

we could find some Forecasted Convective Amplification Deficiency issues and surprise boom moments from looking at parameters that others haven't look into before.

recently I've been noticing hybrid tornadoes tend to form in a type of environment.
also notice that a lot of the high risk Forecasted Convective Amplification Deficiency Oklahoma events have the same mlcape vs dcape issues.

if there is 2 things I'm noticing for tornado research is.
1:they seem to completely ignore moister / wet / dry part of the environment.
2: Dcape seems to be completely ignored however base on the nudger theory it would seem like this would be very important.

I've been thinking a "Weather Science" thread would be great to have. This would definitely fit under the science umbrella too.

Funnily enough, I've been thinking about creating a thread to discuss/share weather parameters--not only those currently in common use (CAPE, SRH, STP, etc.), but others as well (obscure, historical, obsolete, newly-developed, etc.). And not just severe weather, either, but also for other kinds of weather (fire weather, winter weather, etc.).

What's been primarily holding me back (as of recently) is that I've had to deal with other things that are currently ongoing in my life right now, so I've had to put the idea on the back burner for now. However, if someone else reading this wants to start up a thread along these lines, then please do so, as I've had some ideas that I've wanted to contribute for that kind of thread (of course, I'd have to take the time to gather up my sources, make notes of what they say about particular parameters, then try to assemble it all into a coherent post...).

 

[Atlantic]

I don't know much in the weather science field, but I can start the thread for everyone if you all want. @Tennie @Grand Poo Bah @joshoctober16

 

[Clancy]

Various experimental products really starting to sniff out the possible string of threats across the Plains, Midsouth and Midwest. The focal point definitely looks like the Plains up into the Middle MSV, but could see just about anywhere east of the Rockies getting some action, if at least some of these threats were to materialize.

 

[tennessee storm chaser]

Various experimental products really starting to sniff out the possible string of threats across the Plains, Midsouth and Midwest. The focal point definitely looks like the Plains up into the Middle MSV, but could see just about anywhere east of the Rockies getting some action, if at least some of these threats were to materialize.
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Wow. Week 2 looks like mid south snd
Even south get on some
Good action

 

[Clancy]

There's definitely a number of opportunities for severe across the South in this run, taken verbatim, especially with the two troughs outlined in the first two screenshots. The main limiting factor (down South) will be less-than-ideal kinematics, which is often what puts a lid on things this time of year. However, if any systems are able to muster up sufficient shear, it could elevate the tornado risk significantly for the Deep South, especially on that system in the longer range, if it were to evolve as modelled. Mid to upper MSV, up into the Midwest and out in the Lower Plains definitely looks active to me, however. Hopefully chasers can get some good photogenic twisters in sometime over the next 2 weeks.

 

[CheeselandSkies]

Right now the general consensus of models (if it could be called that) seems to be pointing to next Thursday, May 15th and then the following Sunday/Monday, May 18th-19th, as the days to watch for potentially higher-end synoptically evident severe threats. Of course this is all a long ways out so that could change.*

*Edit: And it did. Of course, as soon as I put in the PTO request, 12Z Euro comes in looking a lot less impressive for Sunday 5/18 than the 0Z did.

 

[Grand Poo Bah]

Not getting too excited/concerned at this stage, but SPC does hint at some potential into this region in about a week.

I wouldn't have even posted my theory on upper level drylines if this thread was more active because I wasn't sure it mattered, or that I even understood what it all meant, but seeing it verified by the SPC is really cool! Seems like all the ingredients are abundantly in place across the great plains, midwest, and Ohio valley, but all that's needed now is the trigger to actually set it all off. Is the dry air coming in from west to east cold enough to force the warm air upward?

 

[CheeselandSkies]

I wouldn't have even posted my theory on upper level drylines if this thread was more active because I wasn't sure it mattered, or that I even understood what it all meant, but seeing it verified by the SPC is really cool! Seems like all the ingredients are abundantly in place across the great plains, midwest, and Ohio valley, but all that's needed now is the trigger to actually set it all off. Is the dry air coming in from west to east cold enough to force the warm air upward?

You're getting into details that are too minute to accurately pin down at this range. Right now I'm just really looking at trough timing and geometry (which is still highly variable between model to model and run to run).

 

[Kds86z]

You're getting into details that are too minute to accurately pin down at this range. Right now I'm just really looking at trough timing and geometry (which is still highly variable between model to model and run to run).

 

[ColdFront]

I am super excited for this. Broyles absolutely nailed that day and am very eager to learn exactly what he saw that led to the high risk.

 

[Clancy]

I am super excited for this. Broyles absolutely nailed that day and am very eager to learn exactly what he saw that led to the high risk.

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Very eager to see forecasting perspectives from the horse's mouth; just about the only other video I've seen of Broyles was him falling off a bike.

 

[ColdFront]

Very eager to see forecasting perspectives from the horse's mouth; just about the only other video I've seen of Broyles was him falling off a bike.

Care to share it haha