Why the weird/mixed units for UK Met Office

[Ed Mahmoud]

Latest observations - 1300 on 21 May 08: UKLocation Weather Temp Wind Vis Pressure / trend
Dir Speed Gust
Belfast (Aldergrove) 13.7 °C SE 19 mph 14 km 1015 hPa, Falling
Cardiff (St Athan) 15.3 °C ESE 13 mph 10 km 1015 hPa, Falling
Edinburgh (Gogarbank) 13.2 °C E 9 mph 24 km 1018 hPa, Falling
London (Heathrow) 17.3 °C E 9 mph 16 km 1016 hPa, Falling

From http://www.metoffice.gov.uk/weather/uk/uk_latest_weather.html


Note, temperature in Celcius, which I'd expect from a nation in the EU, visibility in kilometers, pressure in a sub-unit of Pascals. But note the wind speeds.

Why aren't the wind speeds in km/hr, or maybe meters/second?


Now, I have my misgivings about anything called the 'System Internationale', which sounds like the name of a song sung on May Day.

But, while not as immediately intuitive as feet and gallons, it has its uses. I remember when President Carter tried to impose SI ("metric") units on the country. Other than the 2 liter Coke bottle, it didn't really stick. But I watched enough TV weather when temps were given in Celcius and Farenheit to have gotten a pretty good feel for that. And when I see articles about a 27º heat wave in the UK, well, it is good for a chuckle.

But in college, SI units work better. Other than remembering gravity is 9.8 m/s^2, there is no memorizing. The unit of force, a Newton, is the product of mass and acceleration, or Kg.m/s^2. Work is force by distance, energy adds time, and later, when I started reading the SPC web page daily, helicity has the same units as CAPE. The standard oil field equations are pre-metric, so the Petroleum Engineer's handbook is full of conversion factors, and, as said before, all those conversion factors make one appreciate a system without them.


But back to the original question. Why are UK wind speed obs in miles/hour when everything else is SI?

[Ed Mahmoud]

Nothing to add, just wanted this to go up top now that the UK work day has ended.

[KWT]

Well over here we have a strange mix between the old and new way of measuring, we sort of use the imperial and the meteric measures at the same time. There is a good example, using the meteric system for measuring temperature (though F is still very often used even in offical data...) whilst we still use the older system for movement (both wind speeds and also for example road speed limits are in mph.)

[Cryomaniac]

Well over here we have a strange mix between the old and new way of measuring, we sort of use the imperial and the meteric measures at the same time. There is a good example, using the meteric system for measuring temperature (though F is still very often used even in offical data...) whilst we still use the older system for movement (both wind speeds and also for example road speed limits are in mph.)

Yeah, the UK is odd with measurements, hell you only have to look at our pre-decimal currency to see what I mean...

[tropicana]

in canada, we also use the metric system, so Enviroment Canada reports in Celsius, and km/h and hectopascals (similar to millibars, but not the exact same, there is a difference in the decimal point).

road signs are in KM/H but ask anyone their height and their weight, 99% will say it in feet and inches and in lbs.

[AussieMark]

here in Australia we are completely metric