Scattered strong to severe thunderstorms are expected across the Ohio Valley region Friday afternoon and evening. There are various outcomes that remain somewhat broad. Regardless, some combination of scattered supercells and organized clusters, including the potential for long-lived storms as hinted by some deterministic solutions, appears likely somewhere across the Ozarks/OH Valley region Friday afternoon and evening.

 

The severe threat for Friday evening into the night has increased and will probably increase further.  Severe thunderstorms are expected across the Middle Mississippi and Ohio Valley region Friday afternoon and evening. All severe hazards are possible with this activity.

 The eastward-advancing cold front/dryline across MO and the warm front vicinity will be a focus for storm initiation. One or more bowing clusters is possible, in addition to more discrete supercells.  Given vertically veering supercells' wind profiles, significant severe storms appear possible -- with a risk for all hazards accompanying this activity, including very large hail, tornadoes, and intense wind gusts.

I Think the level 3 enhanced risk area will be expanded before Friday.

 

As expected, the SPC has increased the threat level for Friday. A level 3 enhanced risk area now covers southern Indiana, southwestern Ohio, and almost the entire state of Kentucky. A level 2 slight risk area covers extreme southeast Kentucky. 

On Friday afternoon and into Friday night, severe thunderstorms are predicted to form over portions of the middle Mississippi through the lower and middle Ohio Valleys. There may be a few strong supercells in the late afternoon and early evening, which might result in tornadoes and big hail. An upscale expanding and organizing cluster is likely to occur during the evening and overnight hours, posing a chance of powerful, destructive winds and maybe a persistent tornado risk. 

It is generally predicted that this would move east-northeast into the lower Ohio Valley until late Friday afternoon. This might create a climate that supports at least a window of opportunity for long-lived, persistent supercells that could produce a few powerful tornadoes and large to gigantic hail. 
There is still a strong indication in the model output that a significant upscale expanding and organizing cluster will be supported by large-scale forces for rising motion into Friday night and overnight. This could sustain widespread strong surface gusts, sometimes exceeding 74 mph, throughout a region spanning from northern Tennessee to southern Indiana/western Kentucky.

 

 

 

 

This is a radar simulation from the NAM 3K. It is from 10 am EDT Friday to 4 am EDT Saturday.

 

Update:

The timing and exact location will depend on what happens Thursday evening. Weak or no storms then will increase the confidence in severe weather on Friday. The level as of now is medium. The threats will be damaging winds, large/very large hail, tornadoes (some of which could potentially be strong), torrential rainfall

I hope these SHARPpy plots are inaccurate. I'm seeing CAPE values of around 4,200 J/kg in an area around Henderson and Owensboro. CAPE values of less than 1000 J/kg represent weak instability, 1000 to 2500 J/kg moderate instability, 2500 to 4000 J/kg strong instability, and greater than 4000 J/kg extreme instability. Also an STP (CIN) of 7.7 out of 15. If you look at the Effective Layer STP (with CIN) chart, you can see there's around a high probability chance of tornadoes that could reach EF4+. If they form within in a 25 mile radius of the point of this sounding

These are numbers you normally see in what is considered tornado alley. Oklahoma, Kansas, Nebraska, and Texas. 

Seeing numbers like this in Kentucky is why I'm growing concerned about Friday evening.

 

 

Now a Moderate (4/5) threat for a large part of the area for tomorrow. 

 

 

 

This is the info from the conference call this afternoon.

The atmosphere is expected to destabilize again late tomorrow morning and early afternoon. Lines of strong to severe thunderstorms are expected to develop over southeast Missouri Friday afternoon, moving across Kentucky/Indiana during the evening hours.

The severe threats are damaging winds, large/very large hail, tornadoes, potentially strong tornadoes, and torrential rainfall.

I wouldn't be surprised to see the level 4 moderate risk area expanded eastward.