The Telegram (St. John's)

The answer is blowing in the wind!

- CINDY DAY

I love to get weather questions from you; it tells me you’re paying attention. Earlier this month, Rose wrote in with a very good one: “…very curious about the increase in our wind. Where we live we never had winds like we did on Christmas Day and the damage being done…. Is there any scientific reason?”

Rose, there is.

Wind is the movement of air across the Earth’s surface and is produced by difference­s in air pressure. Air pressure is created by the motion, size, and number of gas molecules present in the air; these vary based on the temperatur­e and density of the air.

Extreme contrast in temperatur­es causes wind. All winter, we’ve been hearing about the extreme cold they have experience­d in Ontario and Quebec. Their winter started in November with record cold weather for weeks on end.

Meanwhile, Atlantic Canadians have been bragging about how easy a winter we have had- with milder than normal weather and until recently, very little snow (except for north-eastern NB of course).

So all winter, there was a very cold air mass parked to the west of us while weather systems – some were storms with extra tropical characteri­stics – travelled up the coast with warm air. A south wind ahead of those coastal storms puts warm air in contact with the very cold air just to our west. The pressure difference between the strong, cold high and the deep low pressure in the warm coastal storms made for some very windy days. Since Christmas, we’ve been caught up in that cycle.

Are those windy days behind us? Not quite. Now that we’ve reached the end of March, the strength of the sun is also creating more wind. The spring sun heats the earth’s surface and since warm air is lighter than cold air, the air rises. This process results in more “mixing” of the air, which tends to bring down the stronger winds from the upper atmosphere.

Once we get into May, the cold air masses moderate and the warm air begins to start winning the battle. Fingers crossed!

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