I learned a hard lesson last Sunday.
It was about two hours into my research and half an hour into the writing of this week’s column when I came across a disturbing fact.
Hail occurs in the spring and summer.
Normally this fact would not perturb me, but thinking I was nearing the end of my writing (and thus the beginning of my dinner), I was a bit put off by the news. The reason for my dismay was that I had to start all over.
Earlier in the day, I was stuck in what I thought was a hailstorm and what would be the perfect topic for this week. Alas, I found out a bit late it was no hailstorm. What I had on my hands was a lot of research about a topic for which I could not now use. I will save it up for a rainy summer day.
Take two: all outdoors.
Here are the cold, hard facts: without the heat of the spring and summer, there is only sleet, not hail. Winter precipitation can be variable, and we can have rain, snow, freezing rain, sleet or graupel. (Graupel? I’ll get to that in a minute.)
The culprit last weekend was sleet. The sleet storm came on quickly, pelted hard, and made a clicking sound when it hit me or the ground or anything else.
Sleet is simply pellets or tiny balls of ice. It forms when the air temperature near the surface is colder (below freezing) than the above-freezing temperatures higher up in the atmosphere. Rain or melted snow falls and freezes as it moves down toward the earth through the colder zone. Confirm your identification of sleet with the telltale sound it makes and its bounce at impact.
Besides the seasonal differences between hail and sleet, there are other disparities. Hail is less direct than sleet, which falls down from the sky only once before hitting the ground. Cycling up and down is typical for hail riding on up- and downdrafts associated with cumulonimbus clouds. With each trip, more layers accumulate and hail grows sometimes to amazing sizes that can be fatal to crops, wildlife, and even occasionally people. Sleet is almost always smaller than hail, usually the size of BB-pellets, and feels like someone is throwing bird seed at you.
Now that you know the difference between hail and sleet, add to the precipitation perplexity the distinctions of sleet and graupel. And where does freezing rain fit into all of this?
Graupel is a term for snow pellets, rather than sleet’s ice pellets. Sleet and hail can accumulate, while graupel cannot.
Freezing rain is water with the potential to freeze: it is liquid until it hits something cold — below freezing — which causes the rain to freeze on contact. Another difference between this and sleet is that sleet will not stick to objects the way freezing rain does.
When the sleet hit last weekend, it was both too late and too little to issue a sleet warning. This official weather condition occurs only when more than half an inch of sleet is expected. Luckily, this is rare.
So this winter, while the country gets ready to hail to a new chief, I will be registering my vote for snow over the other forms of wintry precipitation. In the absence of that candidate, make it short and sleet.
Suzan Bellincampi is director of the Felix Neck Wildlife Sanctuary in Edgartown.