Giant hailstones. Photos reported by Saad Aldeen Hmouda

Giant hailstones. Photos reported by Saad Aldeen Hmouda
The capital of Libya, Tripoli has been hit by an unprecedented severe supercell storm on Tuesday, Oct 27th, 2020. The storm produced exceptionally large, *giant* hail, possibly more than 8 inches (20 cm) in diameter. The first reports indicate that hailstones could be one of the largest ever recorded on Earth!

Such hail size would definitely fit into the world's Top 3 giant hailstone events reported globally. Besides the Vivian (south Dakota) hailstorm from 2010 and the so-called 'gargantuan' hailstorm in Argentina in 2018.



EVENT ANALYSIS

The event occurred on Tuesday afternoon (Oct 27th) when an upper trough was moving across the Mediterranean. A trough axis with a frontal boundary was moving from west to east across the southern portions of the Mediterranean sea.

And one of the storms along the front brought an intense organized storm in the early evening hours. Social media were soon flooded with numerous giant hail reports!



Photos reported by Saad Aldeen Hmouda

Photos reported by Saad Aldeen Hmouda
Photos reported by Saad Aldeen Hmouda

Photos reported by Saad Aldeen Hmouda
Hailstorm diameter estimation of Tripoli, Libya hailstone.
© Dr. Mateusz Taszarek
Hailstorm diameter estimation of Tripoli, Libya hailstone.
Conditions ahead and along the front very strongly supportive of severe weather, with very high to extreme instability within a strongly sheared environment. The winds ahead of the trough, strengthening with height, favored organized convective storms. Including rotating, supercell storms.

map storm
A band of convective storms was moving along the front, as seen by the NASA MODIS satellite image below. A discrete supercell storm can be analyzed at the tail-end of the storm.

Tail-end storms tend to be the strongest and most organized in the line as they have the best conditions available for their organization.

Based on the clouds visible over northern Libya, there was likely a north-northeasterly moist inflow advecting from the warm Mediterranean sea further inland. This normally provides backing winds near the surface, which supports an important ingredient, the wind shear.

storm
(Read more here)