Severe WX March 11 - 12, 2020 Threat

[Taylor Campbell]

Today’s and tomorrow’s severe threats are substantial enough for their own thread. Be safe.

 

[Kory]

Yeah tomorrow is giving me vibes of last Monday night.

 

[Bama Ravens]

 

[andyhb]

Yeah tomorrow is giving me vibes of last Monday night.

Basically exchanging better thermos aloft for better thermos toward the surface. The hodograph structure and synoptics are eerily similar.

 

[CheeselandSkies]

Basically exchanging better thermos aloft for better thermos toward the surface. The hodograph structure and synoptics are eerily similar.

An andyhb sighting, must be gettling close to spring!

I wonder if SPC will pull the trigger and introduce higher probabilities for any threat (and thus an enhanced risk). I may be totally off base with this, but I have a feeling that the general public tends to perceive a higher tornado threat with a higher categorical risk (and brighter colors on the map on TV), even if tornado probabilities weren't what triggered the categorical upgrade. This is part of why I thought a 30% hail zone might be warranted last week; aside from the cold temperatures aloft making the requisite hail report coverage itself quite likely. Slight risks are pretty common in the Southeast in spring and don't really scream "60 mile EF3 followed by an EF4."

 

[Kory]

Yawn. This MCS is struggling.

 

[Jacob]

Yawn. This MCS is struggling.

Only storm doing anything right now is the one that just moved from Jefferson into St. Clair county. Bit surprised it doesn't have a warning on it yet

 

[Taylor Campbell]

A beauty right now near Munford. I’m hoping it stays alive for me to see after work.

 

[DRob]

From today's weather.

Storm north of Talladega, over Cheaha State Park


Storm west and tracked south of Greensboro


Showing path of the storm


Showing the storm relative velocity


Showing the projected hail from the storm

 

[Taylor Campbell]

It looks like a significant severe outbreak tomorrow with significant and long track tornadoes a fair possibility.

 

[TornadoFan]

Tornado driven enhanced risk for tomorrow. 10% hatched.

 

[DRob]

Mesoscale Discussion 0168
NWS Storm Prediction Center Norman OK
0921 AM CDT Thu Mar 12 2020

Areas affected...Central MO...Far Southwestern IL

Concerning...Severe potential...Watch possible

Valid 121421Z - 121615Z

Probability of Watch Issuance...40 percent

SUMMARY...Elevated thunderstorms capable of hail will continue
eastward across central/east-central MO over the next few hours.
Trends will be monitored for possible watch issuance.

DISCUSSION...Recent surface analysis places a low over eastern KS
with a warm from extending eastward from this low into west-central
MO and then southwestward into south-central MO/north-central AR.
Thunderstorms have recently developed north of this surface boundary
amidst strong warm-air advection/isentropic ascent promoted by
moderate to low/mid-level flow across OK. Recent mesoanalysis
depicts a 40-45 kt 850mb jet extending across eastern OK into far
southwest MO. This jet is expected to progress gradually eastward
over the next few hours just ahead of the mid-level trough also
progressing eastward.

Expectation is for these elevated storms to continue
eastward/southeastward over the next few hours. Current storm motion
estimate is east-southeastward at 40-45 kt, taking this cluster to
MO/IL border by 17Z. Moderate instability (i.e. MUCAPE around 1000
J/kg) and strong deep-layer shear (i.e. 0-6 km bulk shear around 60
kt) supports organized updrafts. Given the currently elevated storm
character, primary threat with any organized updrafts for the next
few hours will be hail. Threat for damaging wind gusts will increase
with eastern extent as the storms become closer to northward-moving
warm front.

A higher probability for surface-based storms is anticipated farther
east across southern IL, southern IN, MO boothill, and far western
KY later this afternoon. This threat will be addressed in later
outlooks and MDs.

..Mosier/Hart.. 03/12/2020

 

[DRob]

Current radar with convective outlooks and mesoscale discussion outlines.

 

[TornadoFan]

The enhanced risk and hatched tornado risk areas have been enlarged as of the last update.

SPC Day 1 Outlook

Severe weather, tornado, thunderstorm, fire weather, storm report, tornado watch, severe thunderstorm watch, mesoscale discussion, convective outlook products from the Storm Prediction Center.

www.spc.noaa.gov

 

[warneagle]

Tornado watch is up. 70% 2+ TOR, 40% EF2+.

 

[Taylor Campbell]

Watch the storm near Stonefort, IL as it progresses southeast.

 

[CheeselandSkies]

Watch the storm near Stonefort, IL as it progresses southeast.

Been watching it for almost an hour, every time it looks like it's about to take on supercell characteristics it bows out again. I think it's stuck north of the front.

Perhaps one of those "popcorn" discrete cells down by HPX could take off and become a dominant supercell (as hinted at by some prior HRRR runs), but they too are taking their time getting organized.

 

[Taylor Campbell]

Been watching it for almost an hour, every time it looks like it's about to take on supercell characteristics it bows out again. I think it's stuck north of the front.

Perhaps one of those "popcorn" discrete cells down by HPX could take off and become a dominant supercell (as hinted at by some prior HRRR runs), but they too are taking their time getting organized.

It’s about to be south and along the warm front.

 

[CheeselandSkies]

It’s about to be south and along the warm front.

Yeah, if it can turn into a surface-based front rider it would become a beast. Hasn't been quite able to get it done, yet.

 

[Bama Ravens]

Not severe weather related, but it is 81 degrees at my house north of Birmingham right now.