Severe Weather Threat 4/27-4/28, 2024 - (Saturday, Sunday)

NorthGaWeather · Apr 25, 2024

Tempestas Tonitrua said:
Absolutely. Didn’t mean to misread your post and I hope I didn’t come across snarky in mine.

No worries at all! I didn’t think anything of it.

Now, if everything were to come together just right, which is rare, this event could achieve much greater results. I tend to stay on the side that something will limit the full possibilities. Maybe that’s from being burned by bad forecasts in the past.

Tempestas Tonitrua · Apr 25, 2024

NorthGaWeather said:
No worries at all! I didn’t think anything of it.

Now, if everything were to come together just right, which is rare, this event could achieve much greater results. I tend to stay on the side that something will limit the full possibilities. Maybe that’s from being burned by bad forecasts in the past.

Agreed. I think you and I were both coming from the same place in terms of something almost always limiting an event from reaching its full potential

MichelleH · Apr 25, 2024

Fred Gossage said:
If I was hypothetically the SPC outlook forecaster early Saturday morning for that Day 1 outlook, and the short-term model data for the coming afternoon and evening was looking like what the GFS was showing 24-48+ hours ago, I would've been drawing a 45% hatched tornado area across central Oklahoma up into south central Kansas. Since then, there's been a shift toward the pieces of energy within the trough being very slightly disjointed and the trough being a bit more meridional. That is today's GFS taking a step toward the Euro and some of the others with the synoptics, and the GFS has always been the most violent looking of the bunch with the Saturday setup. I don't think this trough geometry adjustment precludes a supercell-driven sigtor threat on Saturday by any means, but once you put that synoptic geometry concern with the potential for earlier initiation and how that synoptic geometry may cause adjacent updrafts to rain into each other and maybe somewhat more efficient cold pooling potential from earlier convection before deep-layer shear really increases (which is now delayed slightly with the meridional trough geometry), it's not too hard to see that the ceiling of this event has been walked back a little. I still think it's firmly a Moderate Risk and maybe even PDS watches... and if we can keep storms spaced, it may be capable of more than that... but just 24-36 hours ago, some of the data (and not even considering the NAM from yesterday) had this setup on the same caliber as 5/24/2011 and some of the infamous multiple-F4+ outbreaks of OK/KS from the 1990s. That's not the case anymore.

Fred! So good to see you here!

Muwx · Apr 25, 2024

Tempestas Tonitrua · Apr 25, 2024

Muwx said:

Lmao of course they are

Tanner · Apr 25, 2024

Muwx said:

Yup, there it is. Low and behold.

Tempestas Tonitrua · Apr 25, 2024

Tanner said:
Yup, there it is. Low and behold.

Cap really snuffed out today’s and last week’s setups. Will be interesting to see if that holds serve on Saturday.

jiharris0220 · Apr 25, 2024

Jesus, Saturday has really fallen off a cliff with model trends today, storm mode looks like pure garbage.
I’m more interested in tomorrow’s threat at this point.

lake.effect · Apr 25, 2024

jiharris0220 said:
Jesus, Saturday has really fallen off a cliff with model trends today, storm mode looks like pure garbage.
I’m more interested in tomorrow’s threat at this point.

How do you figure? NAM is still spitting out insane parameters and is usually overdoes the linear component of storm mode.

jiharris0220 · Apr 25, 2024

Because all other cams also have a linear mode and morning time convection. Directional shear has trended to more parallel, and the trough has also trended more amplitude, which induces more forcing.
Edit: found a tweet that explains what I’m trying to say more clearly.

KCweatherboy · Apr 25, 2024

jiharris0220 said:
Because all other cams also have a linear mode and morning time convection. Directional shear has trended to more parallel, and the trough has also trended more amplitude, which induces more forcing.
Edit: found a tweet that explains what I’m trying to say more clearly.

While you're not wrong about the trend of the GFS, I think it's worth noting that other models still have a less amplified trough. I wouldn't be too quick to write off the severity of the threat until the trough makes it inland tomorrow evening/night and we have a better idea of what it will look like.

jiharris0220 · Apr 25, 2024

It’s not just the gfs though, I can’t really post all 15+ models on here. But all of them show a messy storm mode and morning time convection really stunting instability.

I’m not writing off this event at all, but I’d be lying if I said this still looks like the sure fire tornado outbreak it was yesterday.

But yes, there’s 2 whole days worth of model runs to potentially trend back to an environment more conducive for discrete storms.

Casuarina Head · Apr 25, 2024

How often has linear mode been a “bust” factor this year to date? (Not that this event won’t produce some significant tornadoes, of course...)

jiharris0220 · Apr 25, 2024

Casuarina Head said:
How often has linear mode been a “bust” factor this year to date?

There hasn’t been much in the way of linear “bust” so far, but that’s because there’s hardly been anything in the way of warm sector convection this year in the first place for that kind of failure mode to materialize.

KCweatherboy · Apr 25, 2024

jiharris0220 said:
It’s not just the gfs though, I can’t really post all 15+ models on here. But all of them show a messy storm mode and morning time convection really stunting instability.

I’m not writing off this event at all, but I’d be lying if I said this still looks like the sure fire tornado outbreak it was yesterday.

But yes, there’s 2 whole days worth of model runs to potentially trend back to an environment more conducive for discrete storms.

Well here are all the other models:

At the end of the day in modeling, there is going to be variance which is something that can't be ignored. While yes many of the solutions are more amplified and less favorable than yesterday, there are still plenty of solutions that would be favorable to discrete supercells. And regardless there's still very impressive thermodynamics, so we'll just have to wait and see. Exploring these outcomes is what makes discussing weather forecasting fun imo.

jiharris0220 · Apr 25, 2024

If you don’t mind me asking, how did you create a gif of that?

KCweatherboy · Apr 25, 2024

jiharris0220 said:
If you don’t mind me asking, how did you create a gif of that?

If you click the animation tab on PivotalWeather, you can select different gifs either of the specific model you're on or comparing the models to one another.

Have fun with it! It makes it so much easier to quickly compare different models

jiharris0220 · Apr 25, 2024

Ah, well I just completely made myself look r#$&@%d, of course the thing that literally says “animation”, something I never clicked on or even looked at in the past 4 years I’ve used that app, has the option to make a gif. ‍lol

But anyways thanks for showing me.

Tempestas Tonitrua · Apr 26, 2024

12z HRRR has some discrete and semi-discrete elements firing over southern Oklahoma at 02z Sunday before quickly growing upscale into a line. Noticeable warm nose barely above the surface on a few soundings and some pretty stout caps in places.

jiharris0220 · Apr 26, 2024

Saturday still with much uncertainty between cams, nam still shows no morning convection to stunt tornado threat, while the fv3 does show MC, but to a much lesser extent than what the hrrr displays.

This and storm mode are the deciding factors between a memorizable tornado outbreak or yet again another 2024 class flop.

Severe Weather Threat 4/27-4/28, 2024 - (Saturday, Sunday)

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