Is It Sleet or Graupel?
Snow, freezing rain, and sleet can cause damage to your home and property, not to mention increase fall and personal liability risks. But, there’s another form of winter precipitation that can make for slippery walks called graupel.
You’ve never heard of graupel? You’re not alone. Let’s look at how the most common forms of winter precipitation form and how you can tell the difference.
Snowflakes form in the upper atmosphere where temperatures are 32 degrees or below and there is enough air moisture. If the temperatures remain at freezing all the way to the ground, the snow will stay in its original form.
Sleet forms when falling snow melts after passing through a warm layer of air deep enough to melt it into supercooled drops. These drops then pass through another freezing layer, usually closer to the ground, where it reforms into hard-frozen ice pellets.
Freezing rain develops when falling snow encounters a layer of warm air deep enough for the snow to completely melt and become rain. When these supercooled drops strike the frozen ground (power lines or tree branches), they instantly freeze, forming a thin film of ice.
Sometimes called soft hail or snow pellets, graupel forms when snow falling through the atmosphere encounters a layer of slightly warmer air where supercooled raindrops have also formed. These raindrops get attached to the falling snowflakes, freeze quickly onto the snow, and form graupel. Graupel looks like tiny Styrofoam pellets or the Dippin’ Dots you can get at the mall.
How Can You Tell The Difference Between Sleet and Graupel?
At first glance, graupel and sleet look similar. If you are curious enough to go outside to take a closer look, you’ll see the differences.
Sleet will have an icier look and feel to it, while graupel will be more opaque with softer edges. The easiest way to tell the difference, however, is to pick up a pellet in your fingers and pinch it. Sleet will remain hard and melt gradually, while graupel will “squish” more easily. Graupel is a snowflake at its heart, after all.
Does Graupel Fall in Virginia?
Graupel will form in any climate where the conditions are right, including Virginia. In early March of 2020, a storm in Northern Virginia produced a noteworthy amount of graupel, if social media accounts are a good indicator. Google “Graupel in Virginia” and you will see reports of it all across the Commonwealth.
In case you are wondering why hail isn’t in this list of winter precipitation, it’s because hail is typically associated with summer or warm weather storms.
The next time you have winter precipitation where you live, and it doesn’t quite look like snow or sound like sleet, you could be enjoying a graupel winter display.
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