Rain – But Not Exactly Where Needed Most

The graphic below shows rainfall totals over the past 7 days.  I have outlined within the white line the region of most severe and persistent drought.

Note how much of the Southeast U.S. has received at least an inch of rain over the past week (green-shaded spots).  However, there is an unusual alignment of lower rainfall totals over the core of drought.  Much of this area received less than 1.0 inch, and in some cases, only around 0.50 inch.

Is this a coincidence, or not?  Keep in mind that upper soils within this area are very dry.   Summertime convection is highly dependent on local sources of low-level moisture, e.g., evaporation from soils.  Dry soils could inhibit evaporation and reduce the initiation of convection.   Likewise, if a band of storms were to move over a significantly dry region, rainfall totals could be reduced.  It would be expected the crop health would also be degraded, thus evapotranspiration would also be reduced.