Severe WX March 30th- April 1st 2023 (South, Southeast, Ohio Valley, Upper Midwest)

[tennessee storm chaser]

Buddy the real question is if they whip out a High Risk. (No)

This one definitely has moderate all over it …. Things hold together we see our first high risk potential of the year 4/4 system . But little out there

 

[CheeselandSkies]

18Z GFS getting the low down to 979MB on the IA/MN border at 21Z Friday. Just southeast of the triple point in east-central Iowa is a pretty screamingly obvious target, square in the left exit region of the mid-level jet. For some reason low-level backing isn't stellar despite the powerhouse low. 18Z NAM, surprisingly, is more progressive and somewhat weaker initially but deepens the low from 21Z to 00Z with better low-level shear, with the target right over MBY into north-central IL.

My posts will be focused on the northern target, since that's the one that's in chase range for me. Forecast soundings for the mid-south look plenty volatile as well, despite being further removed from the surface low. Kind of reminds me of the April 28th, 2014 setup when the low was back in the Midwest yet the high risk and significant tornadoes were in MS/AL.

 

[CheeselandSkies]

Also notable that the 00Z NAM forecast dewpoint in east-central Iowa for 21Z tomorrow is 7 degrees. In 48 hours that's supposed to be nearly 60.

 

[MoonBaby]

I’m going to go ahead and guess this will end up sinking to central Alabama. Bet.

 

[MoonBaby]

It’s already trying… unless it’s been this low and my brain moved it up higher prior (that rhymed)

 

[CheeselandSkies]

Last couple of NAM runs (especially 00Z) suggesting the northern end of this setup might struggle with moisture return moreso than previously thought. That cold high pressure tomorrow is really gonna wipe it out. OTOH it is the NAM so... And the precip fields even appear to be popping an arc of semi-discrete convection in that classic sweet spot just southeast of the surface low.

 

[pohnpei]

Wrong thread, this is forecast discussion for the next upcoming event.

ok my bad

 

[CheeselandSkies]

One of the challenging/frustrating things about these highly dynamic setups (which we seem to be on a long string of, although I suppose that's typical for winter/early spring) is that the conditions change so fast, and with (pre-CAM range) model runs only valid every three hours at best, it's hard to get an uncontaminated forecast sounding that's a representative snapshot of the environment that will actually be feeding the storms in terms of both thermodynamics and kinematics.

 

[andyhb]

Last couple of NAM runs (especially 00Z) suggesting the northern end of this setup might struggle with moisture return moreso than previously thought. That cold high pressure tomorrow is really gonna wipe it out. OTOH it is the NAM so... And the precip fields even appear to be popping an arc of semi-discrete convection in that classic sweet spot just southeast of the surface low.

Upper 50s/around 60 dewpoints will do in this case that far north. It will be very cold aloft closer to the ULL.

 

[ColdFront]

One of the challenging/frustrating things about these highly dynamic setups (which we seem to be on a long string of, although I suppose that's typical for winter/early spring) is that the conditions change so fast, and with (pre-CAM range) model runs only valid every three hours at best, it's hard to get an uncontaminated forecast sounding that's a representative snapshot of the environment that will actually be feeding the storms in terms of both thermodynamics and kinematics.

As someone who was only been a serious weather enthusiast for about 3 years, I do have a question.

In some of the bigger, high-end events you saw the lead up to in the past (2011s especially) was there as much model flip flopping and divergence between the modes leading up to those events?

Or was it obvious from the get go with agreement and consistency from the models that these events were the real deal and it was just timing and nailing down location that was the main goal.

These past few months have been my first time utilizing the models, so i could be off base and this is a common occurrence.

 

[andyhb]

As someone who was only been a serious weather enthusiast for about 3 years, I do have a question.

In some of the bigger, high-end events you saw the lead up to in the past (2011s especially) was there as much model flip flopping and divergence between the modes leading up to those events?

Or was it obvious from the get go with agreement and consistency from the models that these events were the real deal.

These past few months have been my first time utilizing the models, so i could be off base and this is a common occurrence.

4/27/2011 was not originally looking like the biggest day of the sequence. April 26th looked bigger up until about 2-3 days out.

 

[ColdFront]

4/27/2011 was not originally looking like the biggest day of the sequence. April 26th looked bigger up until about 2-3 days out.

That’s astounding. I had no idea 4/26 was looking like the main event.

 

[Penitentes]

I really recommend reading through the archived thread here, it gives amazing perspective on the evolution of the threat over the ~week prior to the 27th. Certainly it looked to be significant from a ways off but the true scale of the possible event wasn't immediately apparent.

 

[Austin Dawg]

I really recommend reading through the archived thread here, it gives amazing perspective on the evolution of the threat over the ~week prior to the 27th. Certainly it looked to be significant from a ways off but the true scale of the possible event wasn't immediately apparent.

I revisit different parts often trying to learn more about the different parts leading up to the main event.

 

[notsoencrypted]

Well...

 

[tennessee storm chaser]

Well...

One large enhanced area for sure. . Keeps getting expanded

 

[UK_EF4]

Very strong signal for tornadoes on CSU MLP guidance at this stage.

Unfortunately image did not load

 

[Taylor Campbell]

Very strong signal for tornadoes on CSU MLP guidance at this stage.

Unfortunately image did not load

@UK_EF4, you have to use postimages.org to upload that particular image.

 

[Clancy]

 

[notsoencrypted]

RGEM definitely making a system that would cover that whole big enhanced area.