Assessing Why Convective Clouds are Struggling to Grow Deeper Across Eastern Mississippi

There are several broken bands of heavy showers and embedded thunderstorms moving NNE across Mississippi in association with Tropical Depression Cindy.  East of the KDGX radar across eastern Mississippi, a few showers have developed, but are weak and seem to be struggling.

Here is an animation of 1-minute 0.64 um data across the Gulf Coast region. The deeper convective clouds can be clearly seen across the western and eastern part of the imagery, with a narrow corridor of more shallow cumulus.  There are even a few locations where there are no clouds.

When placing the baseline derived total precipitable water on top of the 0.64 um imagery, you can see there is a relative minimum (values around 1.6 inches). Values to the west and east of this drier corridor were on average around 2.2 inches.

Looking at the airmass RGB within this narrow corridor, there appears to be some upper level moisture with the deeper convection ongoing to the west and east.

Some of this upper level moisture can also be seen on the 6.19um.

However, very dry air is observed in the middle levels on the 7.34 um channel noted by the deep orange colors.
 

There was a NUCAPS pass at 1836 UTC. The cursor on the image is the location of the sounding below.

This sounding confirms how dry the middle and upper levels are in this region, which is very likely chocking off convective development. 

I also looked at a sounding in the location shown below by the cursor in this screen capture. 

 

 

This sounding revealed more moisture below 500 mb, which supports why there is deeper convection to the west. 

In summary, I was able to use an assortment of 1-minute GOES-16 data, the airmass RGB, baseline derived total precipitable water, and NUCAPS sounding data to assess why the cumulus field was struggling to develop into deeper convection. This was an area of interest because of more significant heating in a region with high levels of low level shear. 

-Ironman