ESS55
Prof.
Jin-Yi Yu
–Graupel are ice crystals that undergo extensive
riming
•Lose
six sided shape and smooth out
•Either
falls to the ground or provides a nucleus for hail
–Hail forms as concentric layers of ice build around
graupel
•Formed
as graupel is carried aloft in updrafts
•At
high altitudes, water accreting to graupel freezes, forming a layer
•Hail falls but is eventually carried aloft again by an
updraft where the process
repeats
•The
ultimate size of the hailstone is determined by the intensity of the updraft.
•Great
Plains = highest frequency of hail events
Graupel and Hail