April 27-May 6, 2022 | Tornado Outbreak Sequence

[ElectricStorm]

🤔

[ClicheVortex2014]

Mean cap in south-central KS at 12z on the 18z HRRR. Will be interesting to see how much of it is erased by the end of the run.

[ClicheVortex2014]

11 minutes ago, ClicheVortex2014 said:

Mean cap in south-central KS at 12z on the 18z HRRR. Will be interesting to see how much of it is erased by the end of the run.

Not bad and it's still only 1pm central. However... as usual, I suspect it's overmixing.

Edited April 27, 2022 by ClicheVortex2014

[Iceresistance]

27 minutes ago, OKwx_2001 said:

🤔

Automated station reported 60 mph gusts in the diminishing showers, it looks more like they've made a downburst when they collapsed.

[ClicheVortex2014]

Unusually strong directional shear for the OV... at least at this time of year.

 

[ClicheVortex2014]

Pales in comparison to the setup on Friday but still has some serious potential. I'd argue it has less bust potential than Friday.

 

North-central IN

South of Chicago

 

North of Springfield, IL

Edited April 27, 2022 by ClicheVortex2014

[ElectricStorm]

I'm not a huge fan of the 3km NAM but it's showing some pretty dang high parameters for Friday. Cap doesn't look all that strong across OK/KS either, at least compared to some other models so I'm a little surprised it's not really showing anything forming. But then again it's the 3km NAM and it hardly ever shows much at this range, at least from what I've seen. 

[ClicheVortex2014]

ICT says yikes

Friday remains our best chance of seeing severe storms across the
area. However, chances of storms still seems somewhat conditional
given a rather stout cap forecast over much of the area with only a
narrow area forecast to somewhat erode along the dryline during
the afternoon hours. On the synoptic scale, large scale ascent
will be present which should help further erode the cap along the
dryline and allow for a few isolated to widely scattered discrete
supercells to develop along it.

An additional item of complexity would be the magnitude of large
scale ascent, if the upper trough actually provides too much lift,
perhaps we end up lighting up the whole dryline, so rather than
more isolated to widely scattered storms we have many supercells
that go up quickly along the line and have less of a chance of
staying discrete. As the main trough comes along shore in the next
12-24 hours, we will have to watch for any new trends in the
placement of the forecast trough axis.

All of that said, significant severe hazards remain on the table
for Friday afternoon and evening. By mid afternoon Friday, a very
favorable pattern is setting up. Such that a 60-80kt upper level
jet is set to nose into the warm sector, more perpendicular than
not. Nearly 50kt of 0-6km shear is expected along and ahead of the
dryline, to which the 0-6 km shear vectors will also be oriented
perpendicular to the boundary, which has the best chance of
keeping storm mode discrete supercells. The mid 60s dewpoints and
daytime heating will help support 2,000-3,000 J/kg MLCAPE along a
narrow region in the vicinity of the dryline, where maximum sfc
convergence is expected. Additionally, favorable 0-1km shear
(20+kts) and 0-3km CAPE upwards of 100 J/kg in concert favorable
hodographs and effective SRH upwards of 300 is progged. Should
storms initiate, and stay discrete, significant severe hazards
would be possible, including: 2"+ hail, damaging winds, and a few
tornadoes.

 

[StormfanaticInd]

54 minutes ago, ClicheVortex2014 said:

Pales in comparison to the setup on Friday but still has some serious potential. I'd argue it has less bust potential than Friday.

 

North-central IN

South of Chicago

 

North of Springfield, IL

That warm front needs to be watched for sure. Been noticing that to

[ClicheVortex2014]

33 minutes ago, StormfanaticInd said:

That warm front needs to be watched for sure. Been noticing that to

Just glad a right-mover wouldn't ride the warm front. At least it wouldn't according to the wind profile... not sure if the warm front would help in any way to make it ride down the warm front. I think that's a lot to ask for a warm front.

Edited April 27, 2022 by ClicheVortex2014

[Iceresistance]

 

[StormfanaticInd]

5 minutes ago, Iceresistance said:

 

2008 was a really big year if I remember correctly 

[Iceresistance]

5 minutes ago, Iceresistance said:

 

If Big Joe B says it, RUN!

[StormfanaticInd]

11 minutes ago, ClicheVortex2014 said:

Just glad a right-mover wouldn't ride the warm front. At least it wouldn't according to the wind profile... not sure if the warm front would help in any way to make it ride down the warm front. I think that's a lot to ask for a warm front.

Hope no right movers but you never know around this time of year especially as we head into May

[Iceresistance]

Just now, StormfanaticInd said:

2008 was a really big year if I remember correctly 

2008 was also a La Nina year too.

[Iceresistance]

Mean Supercell Composite is at a 15 in Central Oklahoma on the 18z GEFS, could this be enough to break the cap?

[ClicheVortex2014]

16 minutes ago, StormfanaticInd said:

2008 was a really big year if I remember correctly 

One could say that. Ended up with almost 2200 tornadoes.

[Iceresistance]

The GFS has the Cap in Kansas breakable, but it's almost unbreakable in Oklahoma.

[ElectricStorm]

32 minutes ago, Iceresistance said:

The GFS has the Cap in Kansas breakable, but it's almost unbreakable in Oklahoma.

It's breakable in OK at 21z though which seems to be the trend here. The question is if storms can form early enough to take advantage of it or not 

[Neoncyclone]

8 minutes ago, OKwx_2001 said:

It's breakable in OK at 21z though which seems to be the trend here. The question is if storms can form early enough to take advantage of it or not 

That's what I was about to say, if a boundary initiates convection, or otherwise, i'm not sure how many different mechanism can help initiate storms, then we could see a 2-3 hour window before the cap gets too strong.

21z

[ClicheVortex2014]

1 hour ago, Neoncyclone said:

That's what I was about to say, if a boundary initiates convection, or otherwise, i'm not sure how many different mechanism can help initiate storms, then we could see a 2-3 hour window before the cap gets too strong.

21z

Like ICT said, a strong dryline along with some influences from the strength of the system/jet streak (diffluence, jet streak-forced divergence aloft, etc) should be enough for at least some storms. If they're floating the possibility of too many storms resulting in a quick qlcs, then it's just gonna come down to how long they can stay discrete and how long they can exist before they become elevated or dissipate.

Also... they mention large scale forcing should weaken the cap. I'd imagine that's something that only mesoscale models should be able to handle once they properly handle the strength of the system

Edited April 28, 2022 by ClicheVortex2014

[ClicheVortex2014]

0z HRRR is loading which will go through Friday 7pm Central. Not expecting to see cells at this point knowing the HRRR, but we'll see

[StormfanaticInd]

KIND Hinting at possible severe weather Saturday 

Long Term...(Friday through Wednesday)

Issued at 301 PM EDT Wed Apr 27 2022

 

- Active weather pattern with rain chances through the period

- Strong thunderstorms possible on Saturday.

 

Friday and Saturday

 

The long term will begin with an upper-level ridge situated over the

region. Despite the ridging, we`ll see increasing chances of precip

as a warm front lifts northward within the ridge. At the same time,

a large stacked low pressure system is modeled to be situated off

the New England coast. This feature will allow the jet stream to

amplify slightly, and for the overall progression of the warm front

to slow down. As the front settles over Indiana, isentropic lift and

moisture advection should continue through Friday evening. A chance

of showers will be carried over from the short term.

 

To our west, a strong shortwave trough is expected to eject from the

Rockies midday Friday. Cyclogenesis in the lee of the Rockies

initiates at roughly the same time. The resulting surface low then

quickly intensifies and occludes within the upper-level shortwave.

On Saturday, the now stacked low pressure system will gradually

pinwheel its way eastward towards Indiana. Dynamic forcing enters

the picture in addition to the ongoing isentropic lift, leading to

higher rain and thunderstorm chances Saturday afternoon along the

system`s attendant cold front. Will have to keep an eye on severe

potential since soundings show modest shear within the buoyant warm

sector ahead of the front. Any storms that develop within this

environment have the chance to become strong or even severe.

 

Sunday and Monday

 

Saturday`s closed low departs to the east, allowing for a period of

quiet weather as high pressure builds in. Any ridging behind

Saturday`s system is expected to be brief, given the rather

progressive upper-level pattern that develops in its wake. Another

potent shortwave trough should eject from the Rockies late Sunday

night, or even early Monday morning, albeit further south than the

previous one. Clouds and precip chances then quickly increase, and

chance PoPs have been introduced after about 18z Monday. At this

point, guidance begins to diverge regarding strength and position of

the shortwave trough. Will leave PoPs in the chance category for now

until confidence increases.

 

Monday through Wednesday

 

A majority of guidance continues to show progressive flow into the

middle of the week. Given the active pattern, will keep slight to

chance PoPs in the forecast through the end of the period. Some

models depict a third shortwave emerging from the Rockies around

this time, but lack of consensus leads to rather low confidence

regarding any details. The pattern aloft generally supports

continued active weather.

[ClicheVortex2014]

Cute little supercell in the Texas Panhandle

[ClicheVortex2014]

I'm surprised