Wednesday, April 29, 2015


I've had the chance to think about hail over the last three weeks.  It was horribly destructive, but the science behind it is still interesting. 
(I also wonder if in the days folks had ice boxes they scurried out to pick up the hail to put in their ice boxes--free ice in the summer or spring.)
One thing I noticed after the hail storm were the muddy spots where the hail had smacked the storm door.  Some were pretty high up.  I puzzled over that because it seemed they were too high to have bounced off a muddy surface and then up to the storm door.  Then I saw a good big muddy splatter on the siding about 9 feet high. 
This seemed to indicate that the hail itself contained all the dirt, dust, or debris.  That made me wonder if it picked up the dust when it was being formed or if it picked it up in the air just before it made contact.  From what I read, the hail is formed when supercooled (below freezing, but still in liquid form) water droplets in a cloud encounter any sort of solid material around which to form a nucleus.  That solid material could be dust or debris (or an ice pellet that has already formed) that has been swept up into the cloud by the strong updrafts.  Apparently, the hailstone forms layers as it falls through the cloud or if it is swept up again by an updraft.  Below are some lumpy pieces that I picked up when the hail started falling.
The first pieces to fall weren't as large as the later pieces.  The piece that broke my neighbor's bay window was described as the "size of a lemon."
It was interesting to be sure, but I will be happy to never experience it again.



  1. Very interesting, the high mud splat! For the life of me I cannot see the hail-ball collecting that much dirt as it falls.
    You have me trying to figure 'How this could be?'

    Leaving with the mystery.
    Love from Belmont.

    1. The strong updrafts in the cloud that forms the hailstorm could be picking up that much dirt. If you think about how much dirt and debris a tornado picks up, you kind of get the picture. I think there's probably a lot of pine pollen mixed in with the dust in the case of a hailstorm in April in NC.