This month many of our trees have been buffeted with several days and nights of gusty winds. March is known for being blustery, but this year has been particularly so, testing even our strongest trees.
How will March 2021 stack up against March historically? And what makes the wind blow anyway?
Weather is nature’s attempt to balance the atmosphere and wind is part of this impossible quest which is frankly what makes the atmosphere so interesting. The different types of surfaces such as water, snow, sand, trees, and mountains, as well as the fact that different areas of the planet have different amounts of light create an imbalance of temperature.
Different air temperatures have different pressures and this is where things get really interesting. The greater the pressure difference between two areas, the more wind is required to even things out. An analogy to this is climbing a mountain. The faster you change elevation over distance, the harder the climb, the steeper the terrain. Big pressure differences are like really difficult trails and lead to a lot of wind.
This month we have seen two significant arctic outbreaks preceded by milder-than-average air. As the cold air replaced the milder air, winds moved — sometimes with a damaging effect — through southern New England. The cold air was close to record breaking and with it came lots of high pressure. All that wind was simply the pressure trying to even itself out.
You can see on the charts above where the wind events have occurred — the one at the beginning of the month and the one a few days ago, with smaller ones in between. March is the windiest month here in Greater Boston. April is also windy but then things start to calm down as we get into the summer months.
One of the most interesting statistics about this month for me is the lack of cloudiness. Not only has it been a very dry month, when you look at the sky cover at noon so far we can see this month is far and away significantly clearer than average, less than half the expected cloudiness typically occurring this time of year.
The lack of precipitation this month with all the wind might preclude us from calling these events a “tempest” but the past isn’t prologue when it comes to what weather will do and this March is no exception.
There are still over two weeks left until April, but March 2021 is very likely going to end up dry and somewhat windy, a notable pairing.