Night of the Mini-Tornadoes

I kept being woken last night by sudden blasts of wind against my window. I’d doze for about 15 minutes and then get woken by another sudden blast slamming against the window. The very powerful blasts of wind would only last a few seconds. And the wind seemed to change direction each time. In between blasts there was almost complete calm.

This regime went on all night. And I ended up blearily wondering whether some bodies of air travelled much faster than the air around them, like speeding cars on a motorway weaving in and out of slow-moving traffic. I couldn’t think of any other explanation. I wondered why there weren’t motorway pile-ups of air, as the fast-moving bodies of air ran into the backs of the slow-moving ones.

But in the morning, fully awake with a mug of tea and a cigarette, I thought that there was probably a much better explanation for what I’d been experiencing: strong eddies of spinning air, or mini-tornadoes.

For the most part the wind seems to all blow in more or less the same direction all the time, much like a placid river. But maybe when the wind strengthens beyond some point, the flow of air becomes turbulent, just like a river in flood, and the air becomes filled with eddies (right) as it tumbles over itself. And in these eddies the air is moving very fast, going round in circles, just like in a tornado.

So last night maybe what I experienced was a succession of mini-tornadoes. They were part of a relatively slow moving mass of air, all moving in the same direction. They were like eddies in a river.

They would probably have been invisible. Or less visible than the French tornado of a few days back shown below:

The high winds had made the news. They had not been predicted, it seems.

The Met Office is facing criticism for failing to name a ferocious storm that battered Britain with destructive 95mph winds and another blast of heavy snow.

Thursday’s storm which hit a day after Storm Fionn wasn’t given a name, even though amber and yellow warnings were issued, because the predicted conditions fell just below the criteria…

In Britain, the storm left more than 35,000 homes without power and caused travel chaos as it brought down trees onto rail lines and roads, forced bridges to close and disrupted flights and train and ferry services.

Perhaps it’s very difficult to predict mini-tornadoes. My experience last night was of relatively light winds blowing most of the time, punctuated by brief periods of very high winds. Maybe the 95 mph winds were only found in mini-tornadoes, because the principal prevailing wind was probably not much stronger than 30 or 40 mph.

And perhaps mini-tornadoes would explain why just one tree gets blown down (like the one below) and not the ones next to it. A mini-tornado might only be a few feet or yards in diameter, and the strongest winds within it might be located at one small, single point within it, delivering hammer blows at one single location.

It reminded me that yesterday I’d seen some crows in flight, hundreds of feet in the air, and noticed that they were flying in irregular paths, some going down as the others near them rose. It’s probably hard for birds to fly in very turbulent air. One moment they’ll be thrown downwards, the next lifted suddenly upwards or leftwards or rightwards or forward or back. Maybe some of them even get their wings broken by sudden gusts.

Anyway, my guess is that while the Met Office could predict the average wind speed (which certainly wasn’t 95 mph), they couldn’t predict the mini-tornadoes or the high winds inside them.

One simple physical explanation for the mini-tornadoes might be that if the average speed of the wind cannot be increased over a large geographic area, the wind speed can be raised locally in the mini-tornadoes. So the kinetic energy in the prevailing wind might be ½mv², but be ½mV² inside the mini-tornadoes, where wind speed V (95 mph) is a lot bigger than v (30 mph). In this manner the kinetic energy of the entire air mass could be raised without raising the prevailing wind speed, by having small localised “hot spots” of fast-moving air.

Anyway, if nothing else, it goes to show that we don’t understand very much about weather and climate, and that includes the Met Office.

And I’m going to be dozy for the rest of today: I didn’t get enough sleep last night.

About Frank Davis

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8 Responses to Night of the Mini-Tornadoes

  1. smokingscot says:

    Roughly the same situation here Frank, huge pulse of wind that heralds a squall of rain.

    It also upsets the air inside my house with pressure drops I can feel in those rooms with slightly open windows.

    Afraid the cause isn’t as important to me as the effect, so yes I make sure the car’s clear of trees and slate roofs and the scooter’s tucked away.

    Always have a good supply of earplugs, which I find essential for a good sleep in these conditions. Boots does boxes of them for pin money. Also useful for when I’m out on the scoot doing longish rides. I avoid those cone shaped jobs because they’ll slip out, suggest those with squared ends – much like a big fag filter – you got to compress one end to get them in, then they expand to a nice comfortable fit and remain all night. Just mind to set your phone alarm to very loud!

  2. legiron says:

    I remember reading that the UK gets a lot of tornadoes, but they rarely touch down and rarely get very big. This does seem like a good explanation of why that would be so – and why most of the UK’s tornadoes happen in uninhabited, mostly grassland areas. There’s nothing in the way so the wind can pick up speed, and then form the eddies you describe.

    • Frank Davis says:

      I can’t see any other way to get localised high winds except within some sort of vortex or eddy.

      It’s true on the large scale with cyclones and anticyclones. In those the air is also going round in a large vortex.

      It’s not possible to have bodies of air moving around like trucks on a motorway, overtaking each other, like I was dimly imagining in the night.

      Although the jet streams do actually seem to be streams of high speed air, a bit like motorways. And thermals are bodies of warm air which rise up like bubbles through the atmosphere.

  3. Clicky says:

  4. Rose says:

    Old ghosts resurface in Indiana.

    Blue Print For Success – Countdown 2000 – Ten Years to a Tobacco Free America
    (Sept. 11, 1990)

    P9.”For instance, Colorado, Kentucky, Oregon, Tennessee and Virginia enacted anti-discrimination protections for smokers by prohibiting employers from establishing as a condition of employment that employees and prospective employees must be nonsmokers; thus, putting smokers into a “protected” class. In addition, several states have adopted restrictions on smoking in public places that prevent localities from enacting further restrictions.”

    P19; Any comprehensive Clean Indoor Air statute must not contain provisions that provide civil rights protection for smokers against employment discrimination.

    “Hundreds of smoking-control laws across the country stipulate that in cases of dispute between a smoker and nonsmoker, the nonsmokers wishes prevail.
    Anti-discrimination laws would serve to negate such stipulations. In addition, an anti-discrimination law would give a smoker the power to bring suit against both the employer and the nonsmoker with whom there is a grievance.”

    Indiana group pushes for repeal of protections for smokers
    January 07, 2018

    “INDIANAPOLIS – A group of Indiana health and business organizations is pushing for a repeal of some legal protections given to smokers.
    The Alliance for a Healthier Indiana hopes to get rid of a state law that bans employers from screening job candidates for tobacco use, the Indianapolis Business Journal reported.

    The alliance includes the Indiana Hospital Association, the Indiana Chamber of Commerce, the Indiana State Medical Association, Anthem Blue Cross and Blue Shield in Indiana and the Indiana University Richard M. Fairbanks School of Public Health

    A bill introduced by Republican state Sen. Liz Brown of Fort Wayne would repeal the 1991 law and has the alliance’s support. The measure would allow businesses to require employees to stop using tobacco products, even when not on the clock. It has been assigned to the Senate Committee on Pensions and Labor.

    “I think the intention is simple,” Brown said. “We want to give employers the ability to manage their employees and their insurance costs without the state carving out a special class for protection.”

    • beobrigitte says:

      “I think the intention is simple,” Brown said. “We want to give employers the ability to manage their employees and their insurance costs without the state carving out a special class for protection.”
      Isn’t almost any state carving out a special class for protection (non-smokers – often against their will) already?
      How much money do smokers on a daily basis contribute in tax to any state that non-smokers don’t?

  5. beobrigitte says:

    The winds have been pretty wild up here, too.
    The high winds had made the news. They had not been predicted, it seems.
    I’m not sure about the media, but I did get a “warning” on my weather app on my phone.

    I’m sure the human-made-climate-change-advocates are blaming human-made-climate-change for the storms and are screaming for more control. Didn’t they even blame the moving magnetic north pole on “climate change”?
    https: //
    The long overdue magnetic pole switch has nothing to do with it?
    The science shows that magnetic pole reversal is – in terms of geologic time scales – a common occurrence that happens gradually over millennia. While the conditions that cause polarity reversals are not entirely predictable – the north pole’s movement could subtly change direction, for instance – there is nothing in the millions of years of geologic record to suggest that any of the 2017 doomsday scenarios connected to a pole reversal should be taken seriously. But you never know.
    What happened years and years prior to the pole switch(es)?

    The data do not indicate whether the recent climate changes are man-made, but Chen personally believes the drastic shift in the pole has to be the result of human activities. Meanwhile Ivins thinks he will be able to tease man-made climate change from the data in another six months or so.
    I see. There is an industry that needs justification for it’s existence?

    Let’s face it, should any of the “impending overdue” events e.g. pole switch, super volcano eruption etc. occur, we’ll be rid of tobacco control and the whimpering healthists as we will face REAL problems.

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