Rain, Wind and Fire in the Mountains of New York City

Winter continues its grip on New York City. Every break in the forecast is promptly followed by a reversal, including snow and, usually, wind. The thing about the wind in The City is that it ebbs and flows in bizarre patterns that are “controlled” by the unique “geography” of metropolis. The root of the problem is, I believe, that, like mountains, the skyscrapers of New York City “make their own weather.” Note: if you don’t believe this, visit the top of Haleakala on the Hawaiian Island of Maui. Take a coat. Take two coats.

What happens is that the concrete canyons created by the rows of very tall buildings have the same effect on small amounts of normal wind as a small hose does on water from a faucet. In order to maintain the flow rate through a constriction, the speed must increase. As a younger person doing yard work, you used this principle by pressing your thumb partially over the hose end when watering the lawn. This is Bernoulli’s Equation and the Venturi Effect for those who survived high school physics and remember doing so.

Anyway, when the wind, normally pushed by the prevailing westerlies, hits New York City’s rows of skyscrapers, it has only two means of escape. One is vertical and the other is to move faster in the direction(s) the gaps between and among buildings allow. In the process the wind faces a narrowing passage, which results in higher wind speeds. There are other forces at work, of course, including friction, but that is far too technical for the point I am struggling to make.

Suffice to say, that you can be walking along in relatively still air, maybe even enjoying the lingering 40-degree day if the sun is showing, turn a corner and WHAM! Your eyelids are shoved back and your hair, if you have any, is rearranged. See the header photo at the top of this post. And this:

The effect is similar to walking into a freezer with a large exhaust fan blowing in your face. The effect may last for blocks.

I have not discovered whether New Yorkers have a name for this wind. At first, I thought of Mariah, inspired by that great song from Paint Your Wagon, but Mariah (misspelled everywhere as Maria) just seems so … not New York. My personal favorite is the one syllable word starting with ‘F’ that this blog is too polite to use. But, if asked, I am sure New Yorkers would tell you, as I am now doing, “do not walk with coffee with no top on the cup.” Wind has the same wave-creating effect on an open coffee cup as it does on the surface of a lake or on the ocean. Turn the corner into the wind without a lid and get a coffee bath. Who knew wind could be so troublesome?

Of course, when winter’s icy grip is finally dispatched by spring and then summer humidity arrives, the wind will be a welcome guest again. I am waiting. Any day now. Really.

 

 

 

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