Weekend Hail Storm
What a weekend of damaging hail. The pictures and video tell the story.
Here’s a slide show of photos from wcnc.com.
Hail like this is very rare in the Carolinas especially over such a large area. The thunderstorms that produced this hail were between 45-50,000’ tall and had freezing heights were around 9-10′,000’. The key to getting such large hail were the rotating updrafts, which classified them as supercells. These same rotating updrafts called mesocyclones can lead to tornadoes, but only one touched down. These rotating updrafts I estimated to be around 70-80 mph. The hail stones themselves had terminal velocities of between 60-80mph for the golf ball size hail and between 80-100mph for the baseball size hail. These are just estimated based on a perfect sphere, as you can see most were odd shapes due to collisions with other hail stones and raindrops.
| Measurement | Updraft Speed | |||
|---|---|---|---|---|
| in. | cm. | mph | m/s | |
| bb | < 1/4 | < 0.64 | < 24 | < 11 |
| pea | 1/4 | 0.64 | 24 | 11 |
| marble | 1/2 | 1.3 | 35 | 16 |
| dime | 7/10 | 1.8 | 38 | 17 |
| penny | 3/4 | 1.9 | 40 | 18 |
| nickel | 7/8 | 2.2 | 46 | 21 |
| quarter | 1 | 2.5 | 49 | 22 |
| half dollar | 1 1/4 | 3.2 | 54 | 24 |
| walnut | 1 1/2 | 3.8 | 60 | 27 |
| golf ball | 1 3/4 | 4.4 | 64 | 29 |
| hen egg | 2 | 5.1 | 69 | 31 |
| tennis ball | 2 1/2 | 6.4 | 77 | 34 |
| baseball | 2 3/4 | 7.0 | 81 | 36 |
| tea cup | 3 | 7.6 | 84 | 38 |
| grapefruit | 4 | 10.1 | 98 | 44 |
| softball | 4 1/2 | 11.4 | 103 | 46 |
How hail forms (Courtesy Jetstream NOAA)
You can see how many times the hail circulated based on the rings inside the hail stone. These are from Fort Mill.
If you had damage here’s a complete list of all the official reports if you need them for insurances purposes. Here’s a link to the PDF.
