Strong to severe thunderstorms are in the forecast in western KELOLAND, so let’s take the chance to talk about some of their characteristics.
While eastern KELOLAND stays quiet for the time being, the western part of South Dakota will likely see some rather active weather in the evening. One of the criteria for a storm to be considered “severe” is hail size of at least one inch in diameter. So, let’s take a look at how hail forms within a storm.
Within a thunderstorm, small ice pellets are carried around in what’s called the updraft. These pellets can combine with supercooled water as well as each other before falling through a storm’s downdraft. If the updraft is strong enough, this hailstone can be “recycled” back into the storm and accumulate more water and other smaller ice pellets, thus making the stone bigger. Eventually, the hailstone will become too heavy for the updraft to sustain, and it falls from the storm to the earth.
KELOLAND has seen its fair share of large hailstones. Remember…South Dakota is home to the largest hailstone ever recorded, an 8 inch diameter stone that fell in Vivian in 2010.
The stronger the storm, the stronger the updraft. And the stronger the updraft, the better your chances are of seeing larger hail.