May 7-28, 2022 | Severe Weather/MCS Sequence

[Iceresistance]

The GEFS is starting to show some possible setups in Mid-May in the Central & Southern Plains

[Iceresistance]

Just looked at the SPC, there's an Enhanced risk in the Northern Plains for North Dakota, South Dakota, and Minnesota on D4

[Neoncyclone]

Looks like there's a 2-3 hour window for a monster supercell to mature before going linear

[Chinook]

There has been a long swath of hail reports from just after 12z today to now, with up to 2.5" hail in Wisconsin recently. (7 significant hail reports.) That's a lot of significant hail reports for a morning!

Edited May 9, 2022 by Chinook

[Neoncyclone]

3 minutes ago, Chinook said:

There has been a long swath of hail reports from just after 12z today to now, with up to 2.5" hail in Wisconsin recently. (7 significant hail reports.) That's a lot of significant hail reports for a morning!

Hail will be a threat this afternoon as well! 10% hatched for hail, 10% risk for tornadoes has also been introduced for the area the HRRR is predicting a large supercell to form before things go linear.

 

 

[Neoncyclone]

HRRR still predicting a monster storm, very strong deep-layer shear ahead of the storm before it matures.

[ElectricStorm]

Looks like we could have some pretty big days this week up north, starting today. Thursday and that Day 4 enhanced looks to be the peak of this event, that's not an area where you see a Day 4 enhanced all that often. 

[ClicheVortex2014]

Hrrr has 5000 sbcape/70-80 knots effective shear for the initial supercell. Seems really overdone because that’s ridiculous… but we are in that time of year where that’s possible

[ClicheVortex2014]

12 minutes ago, ClicheVortex2014 said:

Hrrr has 5000 sbcape/70-80 knots effective shear for the initial supercell. Seems really overdone because that’s ridiculous… but we are in that time of year where that’s possible

Ok 4600 sbcape/83 knots effective shear. Close enough

[StormfanaticInd]

Mesoscale Discussion 0700

   NWS Storm Prediction Center Norman OK

   0154 PM CDT Mon May 09 2022

 

   Areas affected...southern/central MN into far northern IA

 

   Concerning...Severe potential...Watch likely 

 

   Valid 091854Z - 092030Z

 

   Probability of Watch Issuance...95 percent

 

   SUMMARY...The airmass across southern MN into northern IA is rapidly

   destabilizing and severe potential is increasing. A tornado watch

   will likely be needed by 20-21z.

 

   DISCUSSION...The airmass across southern MN into far northern IA is

   rapidly recovering from morning convection and quickly

   destabilizating. Mid to upper 60s F surface dewpoints are now

   widespread across northern IA to near the MN state line as

   temperatures have warmed into the upper 60s to mid 70s. This is

   resulting in rapidly eroding MLCIN. Towering cumulus have been noted

   across southwest MN over the past hour or so as a north to south

   oriented surface boundary/dryline quickly progresses eastward. A

   warm front is extending southeast from a surface low near Fargo ND

   toward southeast MN. The warm front is forecast to lift northward

   into central MN/west-central WI over the next few hours. 

 

   While large-scale ascent is forecast to remain rather weak, strong

   vertical shear, both effective and in the 0-1 km layer, steep lapse

   rates and strong instability will support organized supercells.

   Weaker forcing will likely limit the number of storms, but one or

   two intense cells are expected to develop over the next few hours.

   Current VWP data from the KMPX 88-D near the warm frontal zone

   already indicated enlarged, favorably curved hodographs with 0-1 km

   SRH greater than 450 m2/s2. Any cell that develops withing the

   northward retreating warm frontal zone will have enhanced tornado

   potential in addition to large hail and damaging gusts.

[StormfanaticInd]

Heat building 👀

[ClicheVortex2014]

Surprised by the probabilities here. I guess they're expecting things to go linear before any supercell can really get going and put down something strong.

 

[ClicheVortex2014]

Satellite suggests the cap is putting on a fight for now

[ClicheVortex2014]

Cap appears to have broke. Cells are nice and spaced out for now. Mesoanalysis has 2000-3500 sbcape/80 knots effective shear for this area so there should be rapid organization

Edited May 9, 2022 by ClicheVortex2014

[StormfanaticInd]

5 minutes ago, ClicheVortex2014 said:

Cap appears to have broke. Cells are nice and spaced out for now. Mesoanalysis has 2000-3500 sbcape/80 knots effective shear for this area so there should be rapid organization

80 knots with 3000 cape is a bad mix

[ClicheVortex2014]

Tornado warning but not much on radar. A couple cells to the south look quite interesting

[ClicheVortex2014]

That's more like it

 

[StormfanaticInd]

Storms looking impressive 

[ClicheVortex2014]

oh dang

 

[StormfanaticInd]

Not good 😬

[StormfanaticInd]

Just now, StormfanaticInd said:

Not good 😬

Now tornado warned

[ClicheVortex2014]

Messy storm mode today. The one southeast of Minneapolis has my eye for now because it's more discrete. Again, for now.

[ClicheVortex2014]

Might have a tornado either ongoing or soon

 

[Chinook]

This group of storms has been moving towards greater storm-relative helicity but lower surface-based CAPE. I wonder if they will not produce the best tornado chances as they adjust to the changing environment.

[ClicheVortex2014]

Good example of how very favorable conditions can be rendered mostly sub-severe by semi-discrete convection that is just close enough to interfere with eachother. Hell, if they were closer and became linear, the severe threat would be greater.

This is the same kind of thing that happened with a January 2017 high risk day in SE AL/S GA/N FL. The strongest tornado of the day was outside of the high risk and most favorable parameters. The difference was that the cell wasn't being interfered with.