This is how Corbola looked at around 5pm today, after the storm of “round snow”, or graupel, very unusual phenomenon at the end of April, which affected many municipalities in the Polesine and Lower Polesine, from Rovigo, to Villadose, to Adria, to Corbola, to Cavarzere.
“The very cold air from the Arctic coming from Northern Europe feeds a low pressure center that has formed in our seas in Italy. The combination brings rain, snow and even steps, in some cases, as today in Polesine, very copious – explains Maycol Checchinato, founder of the Bpp Meteo weather page – We will have to take this into account until the weekend, even if it is slowly decreasing. The weather will therefore be capricious. Then the heat returns“.
We went from 30 degrees to 5 in the snap of a finger. We all noticed it. However, temperatures will rise in the next few days. “Let’s get used to these sudden changes and sudden changes – concludes Checchinato – which are always part of climate change”.
Returning to the round snow: it is formed by “low-density balls that are generated when small ice particles (ice crystal, snowflake, ice pellet or a small hailstone) fall into the supercooled portion of the cloud at temperatures between 0 and -10 °C.
The liquid droplets smaller ones freeze in contact with the ice particle, transforming into a tiny round and opaque mass with air inclusions inside which give it the appearance of opaque ice (rime). Graupel balls usually form in convective clouds with strong vertical development and which extend well above the freezing level.
They can also form when the snowflake encounters a layer a little warmer with temperatures close to 0°: in these cases the flake does not melt but deforms by rolling up on itself. So, essentially, it is a snowflake “wrapped” in opaque ice (as you can see, the dialect term gives a good idea). Graupel balls. they have irregular shapes with diameters of 2 – 5 mm, have very low density (because there are air pockets in them) and are characterized by the fact that when they touch the ground they do not make noise and also tend to crumble (this is why in English it is also called soft hail or: soft hail).
Tags: #Delta #turns white snow
