Tornado outbreak of July 21, 2019

the Tornado outbreak of July 21, 2019 was a destructive tornado outbreak which primarily effected the lower Ohio Valley and upper Tennessee Valley during the late morning through early evening hours of July 21, 2019. In total 51 tornadoes touched down during a 8 hour period from 11:36AM through 7:50PM Eastern Time.

Meteorological History
The 12Z GFS model run on July 15 suggested a major tornado outbreak was going to unfold in the eastern United States at some point in the July 20-23 range. By July 18, model runs had narrowed down the very different model runs from the previous few days down to a tornado outbreak was possibly going to unfold on July 21 in the late morning and early afternoon hours over the lower Ohio and upper Tennessee valleys. Shortly later, the SPC issued a Day 4 30% severe weather outlook for that area. A Day 3 Enhanced Risk was issued early on July 19 with "large hail and destructive winds being likely, but a few strong tornadoes not being out of the question.", on July 20, CAPE levels were believed to have been in the perfect regions for a tornado outbreak in southern Indiana/northern Kentucky. It was also noted that moisture and warm temperatures would create conditions favorable for severe thunderstorm development in the Upper Tennessee and Lower Ohio Valleys, mainly in the 1-4PM EDT timeframe. Wind shear was forecast to be strong enough to produce some tornadoes. In the 1730Z D2 outlook, the SPC upgraded the Enhanced Risk to a Moderate Risk of Severe Thunderstorms with a 15% SIG (Moderate) tornado potential being the main concern. By 8AM the next morning, temperatures across the lower Ohio Valley had stagnated at 70 degrees as rain showers moved through the area. The SPC issued a High Risk of Severe Thunderstorms around that same time for the Evansville-Owensboro area. The first Severe Thunderstorm Warnings were issued in the 9:00-9:45AM time-frame across western KY. A PDS tornado watch was issued at around 10:00AM local time for the Evansville-Owensboro-Louisville area. At 11:29AM, spotters reported a funnel cloud northwest of Morganfield, Kentucky. The NWS in Paduach issued a tornado warning with the storm at 11:31AM, making it the first tornado warning of the day. Meanwhile widespread severe thunderstorm development had already occurred throughout the area, at 11:36AM, a EF0 tornado touched down about 5 miles north of Morganfield and lifted at 11:38AM. At 11:46AM, radar indicated a strong tornadic signature near Texas City, Illinois (which was only under a slight risk). The NWS in Paducah, concerned about a extremely dangerous tornado that could touch down, issued a PDS Tornado Warning for the city of Texas City at 11:50AM. The first violent tornado of the outbreak touched down at 12:01PM...this is a wip...