Weekend Weather Word 08: Any way the wind blows – The Beaufort Scale

Yep, it’s another Weekend Weather Word, the first one in quite some time, but real life has a way of intervening with my plans. Plus, to be quite frank, I was at a loss for potential topics. Just as I am at a loss now for a decent transition to the actual topic. Ah, feck it, I’ll just take this one. If you’ve been following my weather forecasts, whether here in the office or on the weather blog you’re reading at the moment, you’ve probably noticed that I tend to not give wind speeds in km/h or knots. Instead, I usually write about Force 7-8 winds or other such stuff. Now this Force I’m referring to has nothing to do with the Star Wars movies, and no, I’m not trying to play a Jedi mind trick on you, either. I simply use the Beaufort scale of wind speeds.

Wait, the WHAT??? I’m not surprised you haven’t heard of it, it is mostly used in regards to marine weather. However, I personally find it to be a much more intuitive, if admittedly limited, tool to describe the force of wind. Instead of fiddling around with detailed wind speeds, which most weather models cannot forecast with any degree of high resolution or precision, the Beaufort scale provides you with twelve nice brackets that cover pretty much all of the wind forces that we are likely to observe at hour latitudes, so long as we stay out of Tornado Alley, that is. Force 1 on the Beaufort scale roughly equates to the wind created by the wing movements of an epileptic gnat, whereas Force 12 leaves you wondering whether you should have filed a flight plan for that oak tree that just took flight in your back yard.

Taking a photo of wind is pretty much impossible, the best way to see it is to check for effects on the surface of water, like on this photo taken during a storm back in April 2016.

But how does that scale look exactly, and how did it come about? I’ll answer the second question first. The Beaufort scale was developed by Francis Beaufort, an officer in the Royal Navy. Born in Navan in County Meath in Ireland in 1774, Beaufort was the descendant of French Huguenots. He went to sea at the age of 14, and joined the Royal Navy soon after that, rising to the rank of Commander by 1800. He was no desktop warrior, mind you, sustaining no less than nine wounds while leading a “cutting out” operation, essentially the capture and theft of an enemy vessel in port, in Malaga in 1800. It was five years later, while aboard his first own command, the frigate HMS Woolwich, that Beaufort started working on the wind force scale that was to later bear his name. He didn’t start from scratch, rather building on almost a century of previous work by others, and augmenting this by adding his own observations to build a standardised system of assessing wind speeds and strength. This was desperately needed as by this time, in addition to being involved in the Napoleonic Wars, ships of the Royal Navy were charting and surveying every corner of the globe, making meteorological observations along the way, and what one captain considered ab light breeze might be considered a stiff breeze by another, or even by his own first lieutenant, as executive officers were called back then.

Still, even with the pre-work, it took a number of years before the scale was ready for use in the fleet, especially as Beaufort continued to be an active duty officer, commanding ships such as the captured Danish frigate HMS Frederickstein.  Its first high profile test came in 1831, when the brig HMS Beagle left Devonport Naval Base near Plymouth on a survey expedition to South America. Her commanding officer, Captain Robert FitzRoy, incidentally a friend of Francis Beaufort who himself had by this time become Hydrographer of the Navy, was under orders to stick to the new Beaufort scale when it came to his weather recordings. The five year voyage of HMS Beagle, which included a circumnavigation of the world, was already spectacular in its own right, but has since become immortalised because of a member of the scientific staff on board, a certain young naturalist by the name of Charles Darwin. Five years later, after HMS Beagle had returned home, the Beaufort scale was deployed throughout the fleet.

As I mentioned before, the Beaufort scale works with twelve brackets for wind force. Each of these brackets is tied to certain observable phenomena, such as the formation of waves on water, or the movement of trees or branches. Force 0 and 1 mark calm or near calm conditions, while force 6-8 mark gale force winds, and Force 12 is a full blown hurricane. Speaking of hurricanes, the Beaufort scale was expanded for use in Southeast Asia, with Force 13-17 being used to describe the winds found in tropical cyclones and typhoons. Considering the damage that even a Force 10 or 11 storm can do, we should count our blessings for living in a part of the world that usually doesn’t quite see that level of ferocity. Anyway, back to topic. The fact that the twelve forces of the Beaufort scale are tied to clearly observable phenomena makes them relatable in a way that pure figures, like 80-100 km/h, just can’t do. The human mind is not wired to immediately associate numbers or figures to the forces of nature. Even with that, I’m not going to name and describe the actual forces. Instead, I’ve included pictures and definitions provided by NOAA, the US agency for weather and oceanography. This material is Public Domain, so all of you intellectual property vultures can calm right back down again. Go troll someone else!

While you may not need a scale to tell that this weather looks decidedly unpleasant, determining the strength of the wind or storm is a different matter altogether.

So there you go. That wasn’t so hard, was it? Even though modern anemometers can determine wind speeds down to a fraction of a meter per second, the Beaufort scale still has its place. In fact, it is my firm belief that it is much easier for laymen to grasp the concept behind this scale than it is for them to associate danger with windspeed provided in miles or kilometres per hour, as many weather services are currently doing. While it may make it easier to automatically integrate data from numeric forecast models into computer-generated forecasts, it certainly does not, in my eyes at least, increase public safety.


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s