Global and regional climate update

Is recent flooding and heavy rainfall unusual?

I've written at length about the excessive rainfall the UK has experienced, particularly last year but also since the late 1990's; six out of the years from 1998 to 2012 are in the top ten wettest on record, based on Met Office rainfall data which began in 1910.

There are various theories as to why our summers have been so wet, and why the jet stream has been further south than normal.

It's worth remembering as exceptional as the last few years have seemed, climate history shows us that flooding in the UK has always been normal.

This point is highlighted in research which was carried out by Durham University following the serious summer floods in 2007 and highlighted on the Watts Up With That website this week.

The research is five years old, but it rings very true today, and the prediction made in 2008 of increased flooding and heavy rainfall in subsequent years has proved to be all too correct.

The author Professor Stuart Lane looked back at rainfall patterns starting in the mid 1700's.

He concluded that our climate has always fluctuated between very wet and very dry periods, some of which lasted for a few decades.

Crucially the period from the early 1960's to the late 1990's saw far fewer river flooding episodes compared with before the 1960's and after the 1990's.

Ominously, he points out that because more than three quarters of our flood records started during the 1960's, when there were far fewer river flooding episodes, we have underestimated the frequency of flooding.

And this has a knock on effect as to how much flood plain development local authorities will allow.

It's a vicious circle as more flood plain development is likely to make any future flooding even worse.

The article on the Durham University website can be found by clicking here.

UK weather outlook:

The heavy snow that brought disruption to parts of the UK on Friday has melted rapidly as a result of milder air and rainfall.

The next 48 hours will be dominated by a very common January weather pattern, with a powerful jet stream bringing rain or showers to all areas, accompanied by strong to gale force winds.

There's uncertainty about Friday's weather though, with an Atlantic depression expected to bring rain to parts of the UK.

Just how far north the rain will come is open to question, but with colder air pushing southwards as it clears away, some of it could turn to snow.

2012 Global temperatures:

Provisional Met Office figures show that 2012 was the 9th warmest on record, 0.45C above the 1961-1990 average. This is very close to their prediction for 2012 which was for a global temperature 0.48C above the 1961-1990 average.

According to the UAH satellite temperature measure, 2012 was also the 9th warmest on record.

Follow me on twitter @Hudsonweather


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