No. 100: Jul-Aug 1995
"Some hail fell in a slight to moderate shower which lasted a couple of minutes around 0900 GMT on Christmas Eve. The hailstones were roughly spherical in shape, with a diameter of 4 to 8 mm, and translucent, with a faint, crystalline structure radiating from their centres. There were also some agglomerates of two or three stones and, unusually, a few contained four to as many as eight stones in an irregular but planar arrangement, with the larger ones tending towards a hexagonal conformation and dimensions of approximately 15 x 12 x 6 mm."
(Cinderey, Mike; "Unusual Hail -- 24 December 1993," Weather, 50:194, 1995.)
Comment. That snowflakes may agglomerate in large pancake-like aggregations has often been observed (GWP2 in our catalog: Tornados, Dark Days, etc.*), but this is the first time we have heard of hail being welded together in flat, hexagonal configurations. What draws the separate hailstones together into the same hexagonal geometry displayed by snowflakes?