Mesoscale Discussion 0849
NWS Storm Prediction Center Norman OK
0630 PM CDT Fri May 26 2017
Areas affected...East-central IL...Central into southeast IN
Concerning...Tornado Watch 269...
Valid 262330Z - 270100Z
The severe weather threat for Tornado Watch 269 continues.
SUMMARY...The threat for large hail, damaging wind, and perhaps a
tornado continues across valid portion of Tornado Watch 269. A
downstream severe thunderstorm watch is possible for
central/southeast IN and perhaps southwest OH.
DISCUSSION...At 2330Z, a thunderstorm cluster with an embedded
intense supercell is moving into west-central IN. In the short term,
the threat for large hail and damaging wind will continue with this
cluster, with at least some tornado threat associated with the
long-lived mesocyclone currently moving into Warren and Fountain
counties in Indiana.
The downstream airmass across central IN is not as moist and
unstable as areas further west, but steep midlevel lapse rates and
ascent attendant to the MCV that initiated this cluster will likely
result in maintenance of the convective system for the next few
hours. The tornado threat will tend to diminish with time as the
environment for surface-based convection becomes more hostile, but
some hail and wind threat may persist into this evening into
central/eastern IN and perhaps southwest OH.
Depending on convective trends over the next hour, downstream severe
thunderstorm issuance is possible. Local extension of WW 269 is also
possible if the threat primarily appears to be in the short term.
Meanwhile, redevelopment north of the trailing outflow cannot be
ruled out across portions of central IL, though this risk will
decrease with time this evening.
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 40378879 40518789 40468661 40238561 39908473 39258473
39058566 39078659 39168739 39268826 39488855 39668878