Wow! First day for a while with no weather watches or warnings out! Enjoy!
We thought we would take a little look at what is causing this excessively thundery Summer across the UK. There has been much talk of Spanish Plumes etc which is all fine and well, but as meteorologists we take a look back at what is causing this effect. The weather is pretty simple, put in place a series of events and you get a series of results.
One of the main contributing factors to the large number of storms and showers is the remarkably wet Winter of 2013/14 we had. This has left the soil with plenty of available moisture in which to evaporate during the summer months. If we take the summer of 2003 as an opposite example then after a dry Winter of 2002/3 the available moisture in the soil was so low that even when low pressure made the potential for storms to be available there was so little water available that showers and storms were few and far between.
At present we are in a positive feedback loop. As we get more storms, so the moisture in the soil is still there for more storms to develop and so the cycle continues.
The other (rather weak correlation) is between a developing or weak El Nino and a thundery Summer across Western Europe. This link is still being investigated and is still subject to some debate. But with the weather patterns very much locked in a sluggish regime over the next few weeks it looks as though the end of July and start of August are likely to see further outbreaks of storms.
One thing we have found out is that the Met Office EURO4 model is hopeless at dealing with Spanish Plumes and imported thunderstorms to the point of being useless to meteorologists. It missed each of the main plumes last week, whilst the American GFS picked it up nearly 10 days before.
Oh, and what type of Winter follows a thundery Summer? We will tell you the answer to this soon....
|