Mesoscale Discussion 486

Issued

May 3, 2021, 6:50 AM CDT (11:50 UTC)

Expired

May 3, 2021, 8:45 AM CDT

In force

115 min

Issued by

the Storm Prediction Center

Concerning

Severe potential...watch unlikely

Chance of a watch

20%

The Nashville radar (KOHX), 69 km from the middle of the area, began a volume at 11:52 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

825 
ACUS11 KWNS 031150
SWOMCD
SPC MCD 031150 
TNZ000-031345-

Mesoscale Discussion 0486
NWS Storm Prediction Center Norman OK
0650 AM CDT Mon May 03 2021

Areas affected...Middle Tennessee

Concerning...Severe potential...Watch unlikely 

Valid 031150Z - 031345Z

Probability of Watch Issuance...20 percent

SUMMARY...A few storms may produce locally damaging gusts, with a
threat of a brief tornado as well. Coverage of severe is not
expected to warrant a watch at this time.

DISCUSSION...A line of storms arcing southwestward across Middle TN
and into western TN persists this morning, beneath moderate westerly
flow aloft under a departing shortwave trough. Periodic convergent
shear zones and mainly broad mesocyclones have been noted at times
both with QLCS structures and individual cells.

The northern portion of the deeper showers and thunderstorms are
more favorably oriented for supercells with more of a cross-line
component to the deep-layer shear vector. However, these areas are
also less unstable, with only low 60s temperatures and dewpoints. 

A more prolonged threat perhaps will be with activity farther
southwest, which is in closer proximity to a more unstable air mass
emanating out of MS/AL. Although up to 1000 J/kg MUCAPE exists here,
low-level flow has more of a westerly component, with SRH slowly
decreasing with time. Overall shear remains sufficient at this time,
however, for a severe storms or two, with damaging wind or brief
tornado risk. Given that the shortwave trough continues to lift away
from the area, coverage of severe is expected to remain isolated,
and a watch may not be needed.

..Jewell/Edwards.. 05/03/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...MRX...OHX...HUN...MEG...

LAT...LON   35298785 35588812 35828761 36038661 36158580 36448503
            36248458 35798441 35248482 35148607 35118717 35158767
            35298785

Mesoscale Discussions in Tennessee, 2021Every mesoscale discussion in 2021

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.