Severe WX December 10 & 11, 2021 Severe Threat

[Justin Hindman Hindy]

This is Hindy, it won’t let me log in on my fb account.

I really believe they should issue a mdt risk from eastern Missouri, north eastern ark, and the western 2/3 of Illinois

 

[andyhb]

Probably not a great sign when the dewpoint is 69 at Memphis at 1420z in December...

 

[TornadoFan]

 

[TornadoFan]

Moderate risk issued.

 

[Lori]

Fred and Richard….more thoughts?

 

[TornadoFan]

From the latest SPC outlook:
"Regional 12z soundings revealed
65-70 F boundary-layer dewpoints in the warm sector this morning,
beneath midlevel lapse rates close to 7.5 C/km. Surface heating in
cloud breaks and continued warm/moist advection through the day will
result in destabilization and weakening of convective inhibition in
the open warm sector and along the cold front by this evening, when
storm initiation is expected."

 

[Richardjacks]

I think we are looking at a significant event Memphis and north

 

[andyhb]

Quite a few soundings I've popped from I-40 northward towards I-70 this evening have 0-1 km SRH exceeding 400 m2/s2 and 1000-2000 J/kg of MLCAPE. That is the type of combination that can easily yield strong/violent tornadoes with any supercells and embedded QLCS circulations. Actually a bit surprised they didn't expand the MDT northward towards I-70, especially closer to the warm front where the best wind fields are likely to exist.

 

[chasestormz39]

Quite a few soundings I've popped from I-40 northward towards I-70 this evening have 0-1 km SRH exceeding 400 m2/s2 and 1000-2000 J/kg of MLCAPE. That is the type of combination that can easily yield strong/violent tornadoes with any supercells and embedded QLCS circulations. Actually a bit surprised they didn't expand the MDT northward towards I-70, especially closer to the warm front where the best wind fields are likely to exist.

I wonder if they worry about destabilization because I fully agree. Wouldn’t be surprised to see that expansion with one of the next two convective outlooks. Nonetheless, shaping up to be a dangerous evening and night for many.

 

[Casuarina Head]

Could this event be somewhat similar to 28–29 February 2017* in terms of results? That event featured a D1 15% TOR hatch and several EF2+ tornadoes.

*Included the Perryville, MO, EF4

 

[WesL]

This is Hindy, it won’t let me log in on my fb account.

I really believe they should issue a mdt risk from eastern Missouri, north eastern ark, and the western 2/3 of Illinois

I'll check the FB feature.

 

[Taylor Campbell]

The forcing that appears to be the focal point for supercell development later this afternoon and evening across northeast AR is just about to cross the southeast OK/southwest AR border.

 

[andyhb]

So uhh, that 16z HRRR is probably nudging towards high risk material.

 

[warneagle]

Not great!

 

[JPWX]

16z HRRR Supercell and STP

 

[Clancy]

Yeah that's not too good. UH streaks raking over the Kentucky Bend region per the 16Z HRRR.

 

[tennessee storm chaser]

Latest helicity index just keeps climbing especially along the ms river region Memphis towards lower Ohio valley

 

[Taylor Campbell]

The forcing that appears to be the focal point for supercell development later this afternoon and evening across northeast AR is just about to cross the southeast OK/southwest AR border.

The HRRR’s simulated reflectivity shows deeper returns as early as 2pm just southwest of Little Rock, AR, but maturity looks to take hold by 4pm and later across the moderate risk areas.

 

[Clancy]

Newest D2 update from SPC expands the SLGT southwards.

 

[Taylor Campbell]

Morning soundings in Shreveport, LA and Little Rock, AR showed a significant inversion layer of warm air.