06/08/2022
WATCH LIKELY
Mesoscale Discussion 1089
NWS Storm Prediction Center Norman OK
1238 PM CDT Wed Jun 08 2022
Areas affected...The Ohio River Valley
Concerning...Severe potential...Tornado Watch likely
Valid 081738Z - 081945Z
Probability of Watch Issuance...80 percent
SUMMARY...The potential for severe weather, including a few
tornadoes, will increase in the coming hours for portions of the
Ohio River Valley. A watch will likely be needed to address this
potential.
DISCUSSION...Afternoon observations show a surface low gradually deepening as it translates east towards the OH River Valley region. Ahead of this low, a surface warm front is identified in both surface observations as well as GOES visible imagery in the form of a northward-advancing cumulus field. A diffuse, but discernible, cold front is also noted advancing eastward with the low. Although instability north of this boundary remains marginal, daytime heating (modulated to a degree by cloud cover) and northward advection of mid/upper 60s dewpoints have bolstered MLCAPE values to near 1000 J/kg. This instability is sufficient for deep convection (evidenced by a few ongoing thunderstorms along the front) despite some lingering inhibition. The northward advance of the warm front should allow favorable buoyancy to spread as far north as the lower half ofIN/OH by mid/late afternoon.
Aloft, a seasonally strong upper-jet is supporting 40-50 knots of effective bulk shear both along the warm front and across the warm sector to the south. Considerable veering in the lowest 2-3 km is noted in regional VWPs within the warm frontal zone with a nearly unidirectional flow field above this layer.
This hodograph structure will support the potential for supercells that may pose all hazards, especially along the surface warm front and near the surface low where low-level SRH will be maximized and storm residence time may be adequate to realize the favorable environment. Initially discrete storms appears likely with a gradual transition to clusters and/or a few line segments possible as storms interact along the boundary