It's hailing!
'Grandinando' — gran-di-NAN-do. From 'grandine' (hail). 'Sta grandinando' = it's currently hailing.
Use during a hailstorm — more dramatic than rain and genuinely alarming for Italian farmers. Hail causes significant agricultural damage and is taken very seriously.
'Grandine' means hail (the ice pellets). The verb 'grandinare' means to hail. 'Sta grandinando' uses 'stare + gerundio' for the present continuous — it's happening right now. Hailstorms in Italy can be extreme.
Sono chicchi grossi come noci!
They're hailstones as big as walnuts!
'Chicchi' = hailstones, grains. Comparing size to nuts is very Italian and vivid
La grandine ha distrutto il raccolto.
The hail has destroyed the harvest.
Serious consequence — agricultural devastation is very real in Italian rural areas
Metti la macchina al coperto!
Put the car under cover!
Practical response — hail can dent car bodywork significantly
Hailstorms ('grandinate') are an existential threat to Italian viticulture and agriculture. After a serious hailstorm, local news shows devastated vineyards and orchards. It's an emotional as well as economic event in wine-producing regions.