Mesoscale Discussion 1131
NWS Storm Prediction Center Norman OK
1215 PM CDT Fri Jun 23 2017
Areas affected...Northern KY...Southern/eastern OH...Western
Concerning...Severe potential...Watch possible
Valid 231715Z - 231915Z
Probability of Watch Issuance...40 percent
SUMMARY...A gradual increase in the threat for damaging wind gusts
and perhaps a tornado or two is expected this afternoon. Watch
issuance is possible.
DISCUSSION...A gradual increase in the intensity and coverage of
convection has been noted across portions of southern OH, in advance
of a large precipitation shield (with embedded convection) further
to the northwest. While midlevel lapse rates are poor, given the
influence of the decaying tropical system to the southwest, modest
heating within a very moist environment has resulted in moderate
destabilization, with SBCAPE rising into the 1000-1500 J/kg range
where temperatures have warmed into the low 80s F. Further
intensification is possible, both with the more discrete activity
across southern OH and northern KY, and within the larger convective
plume across central/northern OH as that moves eastward.
With strong deep-layer southwesterly flow over the region, effective
shear has increased into the 40-50 kt range, which is more than
sufficient for some organized storm structures. With unidirectional
wind profiles in place, damaging wind gusts are expected to the
primary threat, though low-level shear is sufficient for a tornado
or two with any semi-discrete supercells that can evolve. Watch
issuance is possible later this afternoon to cover this threat.
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 38828510 39318455 39858324 40268227 40668151 41028071
41138003 40567974 40037995 39388077 38778161 38428240
38558365 38728470 38798507 38828510