The Travails of an April Tropical Low

April development of a tropical storm system is very rare.  The one attempting to get started in the SW Atlantic has an artistic looking low swirl that has the banded features that one would look for in a storm.  So, even if the winds are great and the water temps are marginal why is the storm failing yet to thrive?

First, let's look at the storm:

Well defined swirl in the SW Atlantic.
Source: Univ of Wisconsin SSEC

The failure to thrive seems to be caused by dry air in the atmosphere which is starving the storm of being able to produce the convective (like thunderstorms) activity needed to deepen the system and expand it's influence.

Driest air exists where the low level swirl is located.
Source: Univ of Wisconsin SSEC

As time passes so does the window of opportunity for the system to strengthen before the return of fast westerlies sweeps it away.