Abrolhos squall
An Abrolhos squall is a squall near the Abrolhos Islands off the coast of eastern Brazil that typically occurs from May through August. The squall occurs near 18°S latitude, located between Cabo [de São Tomé] and Cabo Frio.
The southeast trade winds of the tropical South [Atlantic Ocean] acquire heat and moisture traversing the warm Brazilian current offshore, providing moisture for this rain and thundersquall phenomenon. The Abrolhos squall typically occurs along Antarctic cold fronts penetrating into the tropics.