Mesoscale Discussion 1828

Issued

Oct 11, 2021, 12:58 AM CDT (05:58 UTC)

Expired

Oct 11, 2021, 2:30 AM CDT

In force

92 min

Issued by

the Storm Prediction Center

Concerning

Tornado watch 518...520

The Shreveport radar (KSHV), 89 km from the middle of the area, began a volume at 05:58 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.

261 
ACUS11 KWNS 110558
SWOMCD
SPC MCD 110558 
ARZ000-LAZ000-TXZ000-OKZ000-110730-

Mesoscale Discussion 1828
NWS Storm Prediction Center Norman OK
1258 AM CDT Mon Oct 11 2021

Areas affected...Portions of east-central/northeast TX...far
northwestern LA...extreme southeastern OK...and western AR

Concerning...Tornado Watch 518...520...

Valid 110558Z - 110730Z

The severe weather threat for Tornado Watch 518, 520 continues.

SUMMARY...An isolated severe threat should continue in a narrow
corridor early this morning. Downstream watch issuance is not
expected.

DISCUSSION...Recent radar imagery shows a line of storms extending
from parts of east-central TX into western AR early this morning. A
fairly narrow corridor of weak to moderate boundary-layer
instability is present along and just ahead of this ongoing
convection per latest mesoanalysis. With strong low-level and
deep-layer shear present over the confined warm sector, potential
for storm organization will likely continue in the short term (next
1-2 hours). Both damaging winds and perhaps a brief tornado remain a
possibility given the strength of the low-level flow associated with
a 35-45+ kt low-level jet. With time, these storms will encounter
rapidly increasing convective inhibition across western/central AR,
northwestern LA, and east TX. A corresponding decrease in intensity
is expected to gradually occur. At this point, a downstream watch to
the east of Tornado Watches 518/520 is not anticipated.

..Gleason.. 10/11/2021

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

ATTN...WFO...LZK...SHV...HGX...FWD...

LAT...LON   31029654 31579605 32309532 33699479 35269377 35159309
            34699337 33429350 32339355 31679392 30989616 31029654

Mesoscale Discussions in Texas, 2021Mesoscale Discussions in Arkansas, 2021Mesoscale Discussions in Louisiana, 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.