Horses run for cover as spiked hail falls in St. Johns County

Why the unusual looking hail?

Hail like this dropped from the sky over horses and cars Tuesday in St. Johns County.

WORLD GOLF VILLAGE, Fla. – Jagged spiked hail fell from the sky Tuesday morning, sending horses scurrying for cover in St. Johns County.

A swath of 3-inch hail fell out of a severe thunderstorm from the World Golf Village to St. Augustine.

Instead of our typical pea-sized, round hail, dozens of photos and videos on StormPins showed the unique crystal clear and irregular sided hail.

The transparent hail has fewer trapped air bubbles giving it that clear appearance. A wet growth setting allows gases to escape before freezing. More air bubbles generate whiter opaque hailstones.

Lobes develop on large hailstones due to unequal freezing and subsequent layering of freezing water that accentuates and magnifies uneven surface features. 

You can think of the process similar to icicle formation where the flow of liquid water over a hailstone surface freezes at the tip projections.  

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Jacksonville's frequent thunderstorms are often ripe for hail formation but rarely do hailstones get big enough for the growth of these spiked lobes. 

Our abundance of warm surface air saturated with humidity loads raindrops with water which limits how much the hail nucleus freezes.

Tuesday's unusual size is due to low freezing levels for this time of year at 12,500 feet and the moderately unstable air that forced freezing rain drops upwards on fast vertical updrafts. 

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