Monthly Archives: February 2016

What is “sea smoke” and where is it usually seen?

We recently got a question from a reader who had heard the term “sea smoke” while traveling near Superior on a windy, cold winter day.

Amazingly, sea smoke has a very similar physical origin to the “fog” we often encounter as we take a shower. Sea smoke is an example of a phenomena known broadly as steam fog. Continue reading

Category: Phenomena, Seasons

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What is “black ice?”

The term “black ice” refers to one of two conditions: a new layer of ice on water, which appears dark in color because the ice is transparent and so we see the deep water below, or a layer of clear ice on a roadway, which makes for hazardous driving conditions.

In both cases the ice is not black, but transparent, and therefore shows the color of the underlying surface. Continue reading

Category: Seasons, Weather Dangers

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When does the last deep-cold spell of the winter usually come?

As we all work to recover from our recent cold spell, the natural question is: Are we done with bitter cold for the winter?

If we use an overnight low temperature below zero as the definition of a cold spell, then 26 of the 45 winters since 1970-71 have seen a cold spell after Feb. 15 — that’s 64 percent of the time. In fact, in 1974, the last below-zero night was not until March 24, the latest date in the last 45 years. Continue reading

Category: Meteorology, Seasons

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What is thundersnow?

If you were outside Tuesday shoveling that heavy, wet snow, you may have heard thunder during the storm. Some folks indoors also heard the thunder while it was snowing.

You experienced thundersnow — a weather event that is not too common in Madison. When lightning and thunder occur during a snowstorm, the event gets reported as “thundersnow.” Continue reading

Category: Phenomena, Severe Weather

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What is Groundhog Day and do the forecasts work?

Long before computers, the Weather Channel and the Internet, humans needed weather forecasts. Farmers and sailors particularly needed to know if storms were approaching.

Over time, various folklore forecasts, often in the form of short rhymes, were devised and passed down through the generations. Although memorable, the folklore forecasts are of uneven quality—some good, others bad. Continue reading

Category: Climate, Meteorology, Seasons

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