29 Apr 2012

The wettest drought on record?

Much of the UK awoke to another miserable rainy day with winds strong enough to fell trees, snow in the hills and 113 flood warnings – in the midst of an official drought. What is going on?

Scotland and Northern Ireland may have awoken to a clear, cold start but their self-satisfied smirks should be gone by nightfall when rain pushing in from southern England and Wales drowns their good cheer.

The rain, an extra 15mm to 40mm pounding down on near-saturated ground, prompted the Environment Agency to issue 113 flood warning by midday Sunday – 11 of those warning immediate action was needed. Meanwhile, the Met Office issued severe weather warnings for southern England over the next three days. So Britons, many of whom live in areas officially declared in drought, may be forgiven for asking: how can there simultaneously be floods and a drought?

“We need to step back a moment and remember we’ve had two years of dry weather and we can’t compensate for two years of dry weather with a few weeks of rain,” Scarlett Elworthy , Met Office spokeswoman, told Channel 4.

Here comes the rain again

In other words, drought-stricken East Anglia, south east and south west England shouldn’t be surprised if it pours down for the next five days while they are still banned from using hosepipes and told to conserve water. That’s because the rain is simply replenishing rivers and reservoirs after long periods of dry weather.

“The ground gets very compacted and we don’t necessarily get water running through the underground reservoirs which are so essential for our water supplies,” Ms Elworthy said. Instead, as a result of the ground being hard, Britons will have to take a break from drought preparations to prepare for flash floods.

In a normal cycle, water supplies would be recovered during winter months of steady rainfall. By spring and summer, the rain it is largely taken up by growing vegetation. A lot of rainfall goes straight up into the atmosphere during hotter months. That is why rainfall during the summer does not help recover the supplies underground. As for the hosepipe bans, it is up to the water companies to lift the ban, Ms Elworthy said.

Rainy days and Mondays

That’s not likely to happen by Monday, even though the forecast for London and south east England is “chance of scattered showers later, perhaps heavy with a risk of thunder.”

Edinburgh can look forward to “misty” weather with light rain or drizzle on the east coast. While Belfast should be cloudy with light rain or drizzle turning more showery, Cardiff will have persistent strong winds, followed by continuing showers.

The hottest and sunniest place on earth is likely to be Niamey, Niger, where the temperature was a sunny 108 F (42C) on Sunday.

Somewhere over the rainbow

Back in the UK, Britain’s Environment Agency predicts drought conditions to last up to Christmas or beyond, but don’t forget to bring an umbrella.

The Met Office’s outlook for the next 30 days is for “showers or longer spells of rain likely to affect most parts of the UK”.