After an anomalously warm and humid Sunday (April 18th) over Buenos Aires City, a strong supercell associated to very large hail developed some 100 miles west and, after moving East, made a direct hit to the city after sunset. Much of central and eastern Argentina was under a very unstable airmass, with maximum CAPEs of 3000 J/kg and a very decent wind shear (60 knots in the 0-6 km layer).

The incoming of a cold front helped in releasing that convective energy, leading to hailstones of 1.5 inches over the northern part of the city. Reports of up to 2.5 inches-sized hail were received from the northern suburbs of the city as well. In the figures attached, the size of some of the hailstones and the evolution (and displacement) of the supercells are also shown. Radar location is Buenos Aires International Airport (Ezeiza).