Residents of Morro Grande, São José dos Missing, reported that at 10am on Monday there was rain for about a minute of white ice grains (granular snow).

This was verified by the MetSul Meteorology, whose survey indicated freezing rain in Bento Goncalves, Caxias do Sul, San Marcos High Happy, Cinnamon, Capon Beautiful South, Ipe and Vacaria, San Joaquin in Santa Catarina, and possibly in Aparados and Serra Gaucho.

In the case of freezing rain, which looks like a kid sleet, precipitation leaves the cloud like snowflakes on a cold portion of the atmosphere. Then it goes through an intermediate layer of warmer air, but because it is not thick enough, it just melts part of the flakes. Before reaching the surface, however, the flakes are melted by a new layer of cooler air and they freeze yet again, precipitating in the form of ice.

The conditions were thus very conducive to the occurrence of winter precipitation (snow or freezing rain) with cold air temperatures and negative between 1500 and 2000 meters altitude, and the presence of a trough (an area of ​​lower pressure) on the River Grande do Sul and Santa Catarina. It is one of the classic models for snow in southern Brazil: a continental high-pressure trough or cyclone ensuring moisture flow.

Source: Metsul Blog (In Portuguese)