Mesoscale Discussion 1807

Issued

Oct 6, 2021, 7:31 PM CDT (00:31 UTC)

Expired

Oct 6, 2021, 9:00 PM CDT

In force

89 min

Issued by

the Storm Prediction Center

Concerning

Tornado watch 513

The Northeast Alabama radar (KHTX), 81 km from the middle of the area, began a volume at 00:32 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.

425 
ACUS11 KWNS 070031
SWOMCD
SPC MCD 070031 
GAZ000-TNZ000-ALZ000-KYZ000-070200-

Mesoscale Discussion 1807
NWS Storm Prediction Center Norman OK
0731 PM CDT Wed Oct 06 2021

Areas affected...the Middle Tennessee vicinity...and southward into
the northern half of Alabama and northwestern Georgia

Concerning...Tornado Watch 513...

Valid 070031Z - 070200Z

The severe weather threat for Tornado Watch 513 continues.

SUMMARY...Local risk for severe weather continues, with occasionally
stronger/rotating storms.

DISCUSSION...latest radar loop shows that earlier storms which
locally had exhibited low-level rotation have diminished over the
past 1 to 2 hours.  However, area VWPs -- particularly across
northern portions of the WW -- continue to suggest shear sufficient
for brief/local increases in low-level rotation with any
longer-lived storm.  

Overall, a very slow diminishing trend in risk for stronger storms
is expected with time.  However, with the upper low providing cool
mid-level temperatures, and a boundary layer that is nearly
saturated and thus not prone to appreciable diurnal cooling, minimal
but sufficient CAPE will linger into the overnight hours in areas
away from more widespread/ongoing precipitation.  As such, a very
limited/local severe risk will likely continue -- even beyond the
scheduled 03Z expiration of WW 513.  With that said, a new WW is not
expected to be necessary at this time, though we will continue to
monitor convective trends over the next couple of hours in/near the
watch.

..Goss.. 10/07/2021

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

ATTN...WFO...MRX...FFC...OHX...BMX...HUN...PAH...MEG...

LAT...LON   32668728 33818754 34698796 36688824 36528716 35698519
            33978491 33188496 32668728

Mesoscale Discussions in Tennessee, 2021Mesoscale Discussions in Alabama, 2021Mesoscale Discussions in Georgia, 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.