Actually, I do want to tell you about melting in this 46th installment of “Weather Whys”. Specifically, what is the process which leads to eventual ice-out on lakes? Many people would think, quite reasonably, that it gets above freezing and the ice just starts melting away on the top.
But the truth is, the ice melts from the bottom!
Here’s how it works. First, the winter’s snow melts away from the lake’s surface. Then the sun penetrates the ice and begins to warm the underlying water, which in turn warms the underside of the ice, causing it to begin to melt.
Then an interesting thing happens to the lake ice. When its thickness gets down to about a half-foot or a foot, the ice transforms into vertical crystals, known as ice candles. This is also called rotten ice and is unsafe to walk on. This change in the ice allows for more light to get through and not be reflected, and that is when you notice the ice on the lakes looking darker.
Eventually these vertical crystals break apart, as the water beneath them continues to warm.
The final “act” in the ice-out of a lake involves the wind. Now that these vertical crystals of ice have broken apart, they can, and are, moved by the wind. So one day or night, when the wind comes up, the ice candles are all moved by the wind to one side of the lake, making interesting sounds as they move. Some have described it as a kind of tinkling (as in the tinkling of glass).
And where the ice candles had been, before they were moved by the wind, Voila!, you have your open lake again.
Many folks who live near lakes like to record ice-out dates over the years, and I am always very keen to get that type of information. So if you are one of the people who does keep track of ice-out dates on your nearby lake, I’d be pleased if you could call me at the station. The number is 764-4461 then extension 261. Thanks in advance!
Ted Shapiro holds the Broadcast Seal of Approval from both the American Meteorological Society and the National Weather Association. An Alexandria, Va. native, he has been chief meteorologist at WAGM-TV since 2006. Email him at tshapiro@wagmtv.com.
