Mesoscale Discussion 997

Issued

Jun 18, 2021, 4:38 PM EDT (20:38 UTC)

Expired

Jun 18, 2021, 5:45 PM EDT

In force

67 min

Issued by

the Storm Prediction Center

Concerning

Tornado watch 279

Counties Champaign County, OH, Clark County, OH, Darke County, OH, Greene County, OH, Logan County, OH, Miami County, OH, Montgomery County, OH, Preble County, OH, Shelby County, OH

The Cincinnati radar (KILN), 82 km from the middle of the area, began a volume at 20:40 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.

688 
ACUS11 KWNS 182038
SWOMCD
SPC MCD 182038 
OHZ000-182145-

Mesoscale Discussion 0997
NWS Storm Prediction Center Norman OK
0338 PM CDT Fri Jun 18 2021

Areas affected...West-central OH

Concerning...Tornado Watch 279...

Valid 182038Z - 182145Z

The severe weather threat for Tornado Watch 279 continues.

SUMMARY...A continued tornado threat is expected over west-central
OH through 22Z.

DISCUSSION...A supercell has recently become surface-based and
become tornadic across extreme east-central IN. The downstream
environment across west-central OH will continue to modify late this
afternoon as an outflow boundary retreats northeastward, with
temperatures warming through the 80s F and MLCINH continuing to
erode. A relatively narrow corridor is expected to remain favorable
for tornadoes across west-central OH through 22Z, in a region where
weakening inhibition will support continued surface-based
convection, and relatively strong low-level shear/helicity is in
place (per recent KILN VWP) near and to the immediate cool side of
the boundary. 

The ongoing tornadic supercell will likely continue to move
southeast or east-southeast, with additional supercell development
possible from the cluster of storms further to the west across
eastern IN. Any sustained supercell with pose a tornado threat, with
some risk of a strong tornado near the boundary, given the favorable
instability and low-level wind profile. Large hail and locally
damaging wind will also be possible.

..Dean.. 06/18/2021

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

ATTN...WFO...ILN...

LAT...LON   40488473 40558431 40448361 39738371 39458399 39448444
            39548472 39918477 40188476 40488473

Mesoscale Discussions in Ohio, 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.