Monday, 29 June 2009

What's the Definition of a Heatwave?

No, it's not one of those jokes.

Apparently the Met Office has issued a heatwave warning for England and Wales and the Department of Health has asked people to check on elderly friends and family. NHS staff have also been warned to prepare for a surge of elderly and ill patients suffering from the heat.

And what sort of temperatures are we expecting?

Well wait for it........In London, the temperature will rise steadily from about 29C on Sunday to about 32C by the end of the week. Yippeee!!!

What about the rest of us? Well supposedly i
n the rest of UK, temperatures will climb from about 22C to about 29C. Note my scepticism, I say supposedly because this doesn't marry up with the weather here in the North East today and the BBC weather forecast for the rest of the week.

Anyway, come on, is that really what you call a heatwave? I would say it has to get above 30C and I'm pretty positive I've never experienced that here in the North East. Maybe 28 or 29F for a day!

So what is a heatwave?

I was surprised to find that there is no accepted definition of a heatwave.

There is no universal definition of a heat wave and the term is relative to the usual weather in the area or local threshold. The definition recommended by the World Meteorological Organization is when the daily maximum temperature of more than five consecutive days exceeds the average maximum temperature by 5 °C, the normal average period being 1961 to 1990 (which corresponds to the UK baseline of thirty years). Source: UK Climate Projections
So by this definition it really only constitutes a "heatwave" in the London area. Have to ask, does that really constitute a UK heatwave?

Bill Bryson was right when he says he's bewildered by the British attitude to the weather. If you've read Notes From a Small Island you may remember how he describes our tendency to suffer from hyperbole in relation to the weather. Yes, we certainly do exaggerate the slight deviations from the weather norms. "Somebody" also assumes that if it happens in London, that's the whole of the UK.

What's the temperature today here in the North East of England? Well according to the BBC it's a high of 16C, 61F, it's grey and cloudy. Oooh I'm sweltering. Don't think so!!!!!

What's on the cards for tomorrow? Sunny intervals and a huge 18C, 66F. Whey hey!

The highest temperature this week? Wednesday more sunny intervals with a massive 19C, 68F. Oh my goodness, don't think I can cope with that heat!

Well I just can't wait for this heatwave. Better get my bathing costume out and the sun cream and dash out to buy a fan of some description to cool me down or I'll get heatstroke. I'll not go mad and get a quote for the swimming pool just yet. I'll wait for the global warming to take effect. Well they're forecasting that the water level will rise and London will be submerged. So it's lifebelts and rubber dinghies all round then?

I assume it's the best weather we're going to get this summer so I'd better make the most of it.

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