Whither the weather: what's in store this summer

“Somewhat wetter and warmer than average” was the prognosis for summer 2008, as delivered by the UK’s foremost weather forecasters with much fanfare at a briefing on Thursday.

If that sounds a little vague, well, that’s because it is. Seasonal forecasting, which has only been around for the past couple of years, comprises science’s sharpest edge, according to the experts.

Three-month predictions are derived from, among other things, dynamic forecast models, statistical forecast models, ocean temperatures, climate trends and “skill and judgement” – in other words, the gut instincts of those In The Know.

But although they use scientifically well-proven techniques and are, according to the Met Office, “more accurate than methods used by other forecasters,” their capabilities are limited to predicting subtle shifts in seasonal averages, rather than serving as extreme weather crystal balls.

Progressive science

Met Office Director of Government Business Rob Varley said: “Seasonal forecasting, a complex process, is right at the cutting edge of capabilities in the world of science.

“It tells us little about the frequency of extremes – it’s all about averages and probabilities, not extremes and specifics.”

In other words, forecasters can’t say definitively whether there will be a repeat of the devastating deluges that flooded vast swathes of the UK last summer (although the risk is currently considered ‘low’), but they can say with confidence that summer 2008 will be wetter – and warmer – than the average for 1971-2000.

As Varley added, somewhat apologetically: “We can’t tell you which is going to be the warmest and driest week, so that you know when to book your holiday, or if you’ve got a wedding and need a fine day for the marquee – sorry.”

Better than nothing

Which rather begged the question: if there’s so little of use that they can tell us, what’s the point? The answer, it seems, is dependent on who/what you are.

For the likes of you and me, hoping to book off 2008’s single day of unsullied sunshine months in advance, there isn’t one. But for the financial markets, utilities companies, contingency planners and our nation’s fragile infrastructure, even the slightest hint can be invaluable.

“For many people, the level of information is so broad and general, it’s not really useful,” says Varley, “but in reality, even subtle shifts of probability are better than no information at all.

“When so much is at stake, anything is better than nothing – especially given the effects on the financial markets.”

And the effects, as anyone who knows what the weather did last summer will testify, can be devastating – as one journalist tactfully reminded our hosts, noting that their failure to predict the floods in 2007's summer forecast had “attracted flak.”

“There has been a misunderstanding in people’s minds about what we are capable of predicting,” bristled Varley in response. “We predicted a warmer than average summer – and it was. But it was also wetter. It’s a question of understanding what you can and can’t conclude.”

Saturation point

Which is a long-winded way of saying, as one of his cohorts later put it, “We didn’t know!” What they do know is that more people who live in flood-risk areas should register to receive flood warnings – literally, a phone call to your home or business telling you it’s time to batten down the hatches (sign up on the EA’s website or by calling Floodline on 0845 988 1188). When the heavens opened last summer, only 20% of people in flood-prone areas had signed up.

But what can we, the public, expect this summer? A slight chance of cloudier, cooler spells; with above-average rainfall and mean temperatures (although the Met Office was at pains to point out that doesn’t mean there’ll be a long, hot spell – and it could actually mean this summer is cooler than recent years).

As Dr Brian Golding, the Met Office’s head of forecasting, summarised: “The most likely scenario will be three fine days, followed by a thunderstorm.” In other words, don't leave home without an umbrella and sunscreen.

by Laura Snook, News Editor

April 3, 2008