12 Jun 2012

A quick look back at yesterday’s deluge

Yesterday I wrote about the heavy rain that has been drenching the UK over the past five days, bringing flooding to Wales and parts of England. Having looked at the cause of the unsettled weather, the jet stream, I thought that today I’d give a round up of some facts and figures.

The Met Office has released figures showing the amount of rain that has fallen across southern parts of England between 7pm on Sunday and 7am on Tuesday;

Wiggonholt, West Sussex – 72mm

Thorney Island, West Sussex – 68.6mm

Shoreham Airport, West Sussex – 67.8mm

Swanage, Dorset – 55.2mm

Charlwood, Surrey – 55.2mm

Wisley, Surrey – 47mm

St James’s Park, London – 44.6mm

High Wycombe, Bukinghamshire – 37.6mm

Wiggonholt, West Sussex has seen the most rain, with 72mm. This is almost one and a half times of its average June rainfall of 52.9mm. Many other parts of southern England had 40-60mm of rain, with St James’s Park in London recording 44.6mm.

As you can see on the map below, the average rainfall across most of southern England, aside from the tops of the highest hills, is in the range of 36-66mm.

This means that when you take into account all of the rain that’s fallen so far this month, much of southern England has probably seen the average June rainfall already and there’s still 18 days to go!

Britain’s biggest water company, Thames Water, said last week that it expected to be able to lift hosepipe bans for its customers sooner rather than later as a result of the wet weather in April and May. With a wet start to June, there is no doubt that the extra rainfall will help them achieve this.

Another aspect of the weather that has been unseasonable lately has been the maximum temperatures. On Monday, most of southern England struggled to highs of just 11-14C in the cloud and heavy rain.

As illustrated on the map below, at this time of year, maximum temperatures across southern England should be in the range of 18-21C for most places.

Whilst there’ll be a respite from the downpours for many places midweek, another area of low pressure is set to bring wet and windy weather across the UK on Friday.

At the moment it looks like there’ll be 15-30mm of rainfall widely, with some places in the west seeing 40-50mm. However at this stage the detail is still being fined tuned.

One thing that is more certain is that with the ground already saturated from the rain of recent days, further rain will see the risk of localised flooding return.

Don’t forget you can get the latest weather forecast on the Channel 4 Weather website and you can ask me your weather questions on Twitter – @liamdutton

Maps courtesy of the Met Office

Tweets by @liamdutton