Here is a zoomed in visible loop of Invest #91L in the Gulf of Mexico.
— Philippe Papin (@pppapin) July 22, 2020
We may be seeing the initial stages of a closed low-level circulation. Westerly flow is developing on the S flank, aided by inflow into the convective burst.
Recon is flying later today to assess structure. pic.twitter.com/9R6mKyWIIi