Monday the 8th May saw a large storm pass through Wiltshire and Oxfordshire, with a tornado reported in Witney, Eynsham. The winds tore tiles from houses and damaged trees and fences, while hail fell the size of peas. There were some suggestions that this storm was a “supercell” storm, very rare to this country, but a Met Office spokesperson said they did not think the storm was big enough to be classed as a supercell. Helen Chivers said: “Looking at our satellite and radar images, we believe it was simply a very large thunderstorm with a number of funnel clouds extending from the base.
“Supercells cover hundreds of miles and last for hours. But this does seem to have definitely been a tornado.”
Tornadoes are columns of spinning air that form from thunderstorm clouds and touch the ground, we rarely get them powerful enough to cause damage in the UK, but they are more common here in the UK than you would think, find more information on tornadoes here: http://southtyneweather.co.uk/articles/article.php?id=00006
So after a record breaking April ends we have continued with the wet weather into May. After a few days respite for South Tyneside the rain has returned, with over 22mm recorded in the past couple of days. Mind you, that amount is nothing compared to some places, the highest rainfall yesterday (10/05/12) as confirmed by the Met Office, was at Shap in Cumbria where a staggering 62.8mm fell. Many people would expect May to be a lot warmer and drier than what it has been, but as I said recently in my interview with the Shields Gazette the weather will do whatever it wants, it’s one of the things we have no control over. Saying that, our weather has been pretty dreadful lately, and one of the reasons behind this is the position of the northern hemisphere jet stream. The jet stream, as explained in the “weather explained” section of this website, is a narrow band of extremely fast westerly winds very high up in the atmosphere. These winds can and do change position, and can go from quite a straight line to something more resembling a snake, or a twisting river. During the past few months we have experienced what is known as a blocking pattern, where instead of its usual eastwards direction it goes more north and south. Regardless of this March was one of the warmest and driest on record, while April has been one of the wettest on record. The position of the blocking feature is what has caused these differences, in March it was positioned north of the UK, pulling in high pressure, which increased the temperatures and prevented the more usual march weather from the Atlantic reaching us. As April began the pattern headed west, the more northerly part moved over the North Atlantic ocean, while the southern end passed south of the UK into France and Spain. This brought an area of low pressure to the UK, with cloud, low temperatures and rainfall. As the pattern is still “blocked” the usual west – east jet stream that pushes weather systems through us was absent, and this meant the low pressure was trapped over the UK, which resulted in the extreme rainfall we have had. The following video from the Met Office explains more about the jet stream:
Well we have had some pretty awesome weather over the past few months, March could easily have been mistaken for July, and April, well, I think some parts of the country were beginning to consider building an ark! March was one of the driest and sunniest on record, and Aboyne, in Aberdeenshire recorded a temperature of 23.6C on Tuesday 27 March, beating the record of 23.2C set at Cromdale, near Grantown on Spey, the previous afternoon. The month began fine and dry, and by the 20th most of the UK basked in glorious sunshine. This all came to an abrupt end as cooler and cloudier conditions arrived by the end of the month. A hosepipe ban in several counties in the south of England was declared and came into force on the 5th April. This is a result of the 2 very dry years we have had lately. Typically though, no sooner was the drought declared than the heavens opened, and by the end of April many of the drought ridden areas were under water as several rivers burst their banks. Some people have commented that this is the wettest drought ever, but 1 month of record breaking rainfall is not enough to lift the affected areas out of drought, although it has been a massive help.