"Floody hell! Why is the weather so bad?" (UK)

The floods that have wreaked havoc on the UK for much of the summer can be blamed on an errant jet stream, according to climate experts.

The jet stream is a band of fast-moving air which is created when southern warm air collides with northern cold air at about 30,000 feet.

Its position has a large bearing on UK weather and this year it has not moved as far north as it usually does.

Meteorologist Marco Petagna said: "This year it has been much further south for much of the summer and we have seen areas of low pressure right across the UK."

Low pressure, which tends to accompany the jet stream, has caused the heavy rainfall.

Another theory for the relentless bad weather is that the Azores high - a band of high pressure over the mid-Atlantic that normally pushes north into the UK during the summer - has been prevented from doing so by the jet stream.

Mr Petagna said there were many possible explanations about why the jet stream is behaving this way but one is that the La Nina phenomenon in the Equatorial Pacific may be to blame...

He said both phenomena were linked to climate change - another possible explanation for the inclement UK weather.

See also:

Human activity linked to heavier rainfall

Greenhouse gas emissions from human activity are causing global shifts in rainfall patterns and contributing to wetter weather over the UK, climate scientists say today.

Their study is the first to find a "human fingerprint" in the rainfall changes which have been detected in a belt of the northern hemisphere stretching from the Mediterranean to the UK to Norway.

The results, based on a global comparison of weather records going back to 1925, suggest that levels of rainfall across the UK have increased steadily by an average of 6.2 millimetres every decade. At least half of the extra rainfall and possibly up to 85% is caused by the impact of greenhouse gas emissions, the scientists conclude...

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350,000 without clean water as flood threat moves to Thames Valley

One third of a million people in the west of England will remain without clean running water for at least a week as a result of the worst floods to have struck the UK in the last 60 years.

Severn Trent Water said this morning that 350,000 customers would remain dependent on 3 million litres of bottled water delivered by the Army each day, and on a fleet of 900 mini-tankers parked in flood-stricken locations to dispense drinking water.

Gloucestershire County Council said several bowsers were being vandalised amid frustrations over the water supply.

With supermarket stocks running low as far as Bristol, hundreds of people gathered outside a Tesco supermarket at Quedgeley in Gloucester, awaiting the arrival of thousands of bottles of water. The water was set to arrive with an Army escort to ward off looters.

Army Brigadier Jolyon Jackson urged the public to stay calm and added: “There is enough water for everyone.”

Meanwhile, residents along the Thames Valley were warned to remain on high alert for the next two days to protect their homes from the river, which it is feared has yet to reach its high water mark...

Forecasters predict better weather today but more showers this week and heavy rain on Thursday, and the Environment Agency has warned that if these are substantial it would not take much for river levels to start to rise again.
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We've been having an odd jet stream this summer as well. It seems to have been going high out west - like Montana - and low in the Midwest. For us, it has meant cooler weather and lower humidity than usual.