Weather Clocks & British Bank Holidays
The term 'British Bank Holiday Weather' conjures up many things in people's minds. And being a weather-obsessed bunch ourselves, we also have our memories of Bank Holiday weekends that were either glorious or complete wash outs.
It's not quite true that the British public always find themselves in the rain, wishing they'd stayed at home instead of visiting a local (or distant) National Trust monument for a walk and a picnic. However, the weather is still crucial to everyone's enjoyment of the long weekends. Indeed, we know our Weather Clocks can herald in excitement or worry in equal measure!
When the weather is important to people we also know our clocks become the centre of attention. And if their they're at all optimistic or pessimistic it can be the cause for a few raised eyebrows!
Luckily for all of us, more goes into the Met Office's (and other forecasters) data crunching than just the air pressure movements that the clocks rely on. Modern forecasting has come a long, long way from the barometers of old that our clocks are modelled on.
The Easter Bank Holiday weekend of 2019, was a prime example of how weather forecasting heavily relies on other meteorological changes than barometric pressure.
For the whole Easter weekend of 2019, the Weather Clocks at Bramwell Brown headquarters (and nearly all over the British Isles!) were showing 'Rain' as a forecast from Saturday through to Easter Monday even though the weather outside was glorious.
The reason for this was that the air pressure was simply constantly falling from a high that had arrived on Thursday before the weekend.
It only stopped falling at a steady but swift rate on Monday afternoon.
With the clocks blind to anything else going on around them apart from air pressure changes (for example, temperature or humidity), they were doing the best they could with the information to hand.
In more normal circumstances, during nearly any other period of several days of dropping air pressure, the weather soon to arrive would include cloud and rain. It's just during that Easter weekend, the low pressure moving in was not following on as fast as usual due to the sheer size of the high pressure area sitting over the British Isles.
This is a chart showing the air pressure movements in London on Saturday of the Easter weekend whilst the weather was glorious outside:
And here is the air pressure movements on the Easter Sunday, with continuing good conditions:
This final chart shows air pressure movements on Easter Monday. Finally, the drop begins to level out after falling from 1031mb down to 1001mb over the course of the weekend:
So whilst the country baked, the clocks kept their pessimistic forecast. They were totally unaware of the good conditions outside - with only their single air pressure sensor to go on.
So, this coming May Bank Holiday, why don't you do a little experiment and compare your own Weather Clock's movements to the air pressure changes in your location?
You can visit the excellent website, Darksky, to see air pressure changes in your location over the past several days:
- Visit www.darksky.net
- Enter your location
- Scroll down and select 'Time Machine'
- Input the today's, yesterday's (or any!) date you like
- Scroll down and take a look at the handy air pressure charts like those above
Whatever you're up to this Bank Holiday, we hope you have a super time! BB