Speaking of which, the SPC did expand the marginal risk area down to the river for early tomorrow morning. This is in regards to a large hail threat due to low freezing levels and a passing warm front.
https://www.spc.noaa.gov/products/outlook/day1otlk.html
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE
OHIO VALLEY AND GREAT LAKES...
...SUMMARY...
Isolated late-night hail is possible across portions of the central
Great Lakes region.
...Synopsis...
A mid-level trough will dig across the Pacific Northwest today with
a mostly zonal mid-level pattern across the eastern CONUS. Within
that zonal flow, a weak shortwave trough is forecast to move through
the Great Lakes/Ohio Valley late tonight and could result in some
thunderstorms capable of large hail.
A gradual strengthening of the low-level jet is anticipated through
the day today from the Ohio Valley into the Great Lakes as a
mid-level trough advances eastward. This will lead to poleward
moisture transport centered around 850mb. This moist plume combined
with very steep (8-8.5 C/km) mid-level lapse rates will lead to
increasing elevated instability during the overnight period.
Convective initiation remains the primary question during the
overnight period. A trough is present at both 850mb and 500mb in 12Z
guidance, but they are not quite phased. This leads to
weakening/veering 850mb flow during the period when height falls and
500mb dCVA arrives across the region. This is likely an explanatory
factor for the lack of storm coverage by most CAM guidance.
Nonetheless, global guidance continues to show significant
convective precipitation from southern Michigan to northern
Tennessee.
Given 1000 to 2000 J/kg MUCAPE and effective shear of 45-50 knots
(highest across southern Indiana), a conditional threat for elevated
supercells capable of large hail exists tonight. Have expanded the
marginal risk farther south in Indiana to account for this threat.
It is worth mentioning there is at least some threat farther south
into Kentucky where strong instability and shear are present which
would support supercells also. However, have confined the marginal
risk to areas where better mid-level support is expected early
Tuesday morning.