RIO DE JANEIRO, BRAZIL - An extratropical cyclone with explosive features is forming near the border between Brazil and Uruguay, in southeastern Rio Grande do Sul. The phenomenon, known as a bomb cyclone, is a rare event in summer.
"It occurs when there is an explosive formation with a drop in atmospheric pressure of over 24 hPa in 24 hours, that is, when the pressure drops at a rate of 1 hPa per hour. This phenomenon occurs at higher latitudes, further south, and typically in winter months so it is completely atypical," explains meteorologist Estael Sias.
The Brazilian region most affected . . .