Valid 130100Z – 131200Z
…THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM IL TO
SOUTHWEST OH…
…SUMMARY…
Scattered severe thunderstorms are expected to develop this evening
across Illinois and Indiana into southwest Ohio later tonight.
Damaging winds are the primary threat.
…01Z Update…
Organized deep convection has struggled to develop early this
evening across the Mid MS Valley in the wake of early-day remnant
MCS. 13/00z sounding from DVN supports this delayed development with
poor lapse rates and seasonally weak buoyancy. However, ILX exhibits
substantial MUCAPE with ample shear for sustained rotating updrafts.
Over the last half hour or so scattered updrafts have gradually
deepened across central IL such that lightning is now observed along
a corridor from Adams County to Macon County. Latest thinking is
convection will gradually grow upscale, shifting east toward central
IN within broad westerly flow regime. Have lowered severe probs
across much of IA and northern IL to reflect a more narrow corridor
of expected severe. Damaging winds should be the greatest severe
risk with this activity.
Elsewhere, isolated supercell has developed ahead of upper trough
south of MOT. This storm has evolved along progressive front and
should propagate southeast along a narrow corridor of instability
with an attendant threat for primarily hail.
High-based convection across the southern Plains is expected to
linger across the TX Panhandle into northern OK/southeast KS for the
next several hours. Large temp/dew point spreads and ample PW
appears supportive of at least an isolated damaging wind threat.
..Darrow.. 08/13/2019
$$