Severe Weather 2021

[tennessee storm chaser]

Spc has highlighted large area day 4 plains southern plains … models agree there could be day 5 threat further east toward Tennessee valley midsouth … could be buisy next week… euro still looks fairly ominous to me

 

[Tennie]

Spc has highlighted large area day 4 plains southern plains … models agree there could be day 5 threat further east toward Tennessee valley midsouth … could be buisy next week… euro still looks fairly ominous to me

For reference, here's the D4 outlook:

ZCZC SPCSWOD48 ALL
ACUS48 KWNS 210818
SPC AC 210818

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0318 AM CDT Thu Oct 21 2021

Valid 241200Z - 291200Z

...DISCUSSION...
(Day 4) Models are trending toward better agreement and have
demonstrated some run-to-run consistency regarding the evolution of
a southern-stream shortwave trough forecast to amplify as it
approaches the southern and central High Plains Saturday night. This
feature will move through the central/southern Plains Sunday before
reaching the middle/lower MS Valley Sunday evening. There are still
some model differences, particularly with regard to the amplitude
and speed of this system.

Deepening lee low should be situated over central KS by 12Z Sunday
with a trailing cold front extending southwestward into western TX.
A warm front will stretch eastward from the low through northern KS
and into central MO. Partially modified Gulf air will advect through
the warm sector beneath steeper mid-level lapse rates resulting in
moderate instability during the afternoon. A capping inversion will
delay surface-based thunderstorm initiation until mid afternoon when
storms will likely develop along the cold front across central
eastern KS into eastern OK as well as farther east along the warm
conveyor belt into the lower MS Valley. Vertical wind profiles will
support organized storms including supercells with potential for all
severe hazards. Given some lingering model differences, will only
introduce 15% category for this outlook, but higher probabilities
might be warranted with better model agreement in later updates.

(Day 5) - A severe threat will probably persist as this feature
continues into the TN Valley region Monday and possibly the Middle
Atlantic region Tuesday. However, model difference become more
substantial at this time frame, so will defer introduction of any
categorical risk areas to possibly the next update.

(Days 6-7) - Models including most ensemble members are in
reasonable agreement regarding the approach of an upper trough into
the Plains with robust moisture return toward the early and middle
part of next week. If these trends continue, a severe risk area may
be introduced for portions of the central and southern Plains in the
next 4-8 outlook update.

..Dial.. 10/21/2021

CLICK TO GET WUUS48 PTSD48 PRODUCT

 

[Clancy]

While it's definitely prone to change and isn't a sure indicator, CIPS seems to be picking up on the system for next Wednesday (snapshot valid at 00Z on the 28th).

 

[CheeselandSkies]

While it's definitely prone to change and isn't a sure indicator, CIPS seems to be picking up on the system for next Wednesday (snapshot valid at 00Z on the 28th).
View attachment 10530

Everybody's favorite day of the week in Dixie Alley!

12Z GFS is more progressive with the first trough (doesn't cut it off over the east), depicting potential threats from the Plains eastward Sunday through the middle of next week. Sunday is in NAM range and some forecast soundings along the warm front over Missouri/west-central to southwest Illinois look pretty ominous.

 

[tennessee storm chaser]

Everybody's favorite day of the week in Dixie Alley!

12Z GFS is more progressive with the first trough (doesn't cut it off over the east), depicting potential threats from the Plains eastward Sunday through the middle of next week. Sunday is in NAM range and some forecast soundings along the warm front over Missouri/west-central to southwest Illinois look pretty ominous.

Agree. Going over some gfs 12 z guidance. Could be looking at 30 percent area as early morning update southern plains … next week looks buisy

 

[Weatherphreak]

The yearly Halloween storm. Always seems to be a severe threat the week of Halloween followed by cooler temps. Not quite getting the colder temps though.

 

[Clancy]

SPC put out D6 (Wed) risk for the SE.

 

[Clancy]

CIPS doesn't seem to like next Wednesday. This is the tornado probability specifically. (Sorry for the awful crop it wouldn't let me save the image and I'm on mobile )

 

[Weatherphreak]

Spann mentioned it this morning. He usually doesn't start sounding the alarm this early unless its a pretty strong signal.

 

[TH2002]

GFS model is showing some activity for D3/Sun but pretty much saying "nothing to see here" as far as D6/Wed is concerned. Obviously there is a lot of variation in the different models to say with any certainty how things will unfold next week.

 

[warneagle]

Tornado on the ground near Linneus, MO.

 

[atrainguy]

Damage pics are popping up on Twitter from Purdin, MO.

 

[atrainguy]

A pic of the tornado itself from earlier.

 

[TornadoFan]

Holy....

 

[OHWX97]

Two damaging tornadoes in progress in southeast Missouri.

 

[TornadoFan]

That one headed towards Fredericktown looks violent.

 

[TH2002]

Yep dual couplets. Wow...

 

[OHWX97]

That one headed towards Fredericktown looks violent.

No kidding... that's not good at all.

 

[cincywx]

not hard to see where the tornadoes are on CC

 

[TornadoFan]

The cell down by Annapolis, MO is rotating hard as well.