Tornadoes strike Britain

[Weatherwarning]

Can anybody tell me why Britain is suffering from more tornadoes (see express.co.uk)?

[P.K.]

There is no evidence we are having more tornadoes, but reporting has improved over the last few years. GW is not proven to be having an effect which you asked in the other thread. We have had a T2-3 and a T4 over the last couple of days though.

[Weatherwarning]

Thanks...but given the events in recent days and (from what I've read) in recent years, can it all be put down to improved reporting?

Isn't it possible that Gw is having SOME effect? The British weather does seem to be evolving...

[Yarrah]

Weather in the western part of Europe is changing faster then in the rest of world. The exact reason of this faster then normal change isn't known, but the KNMI has just started with a scientific research on this topic.

[P.K.]

Thanks...but given the events in recent days and (from what I've read) in recent years, can it all be put down to improved reporting?

Isn't it possible that Gw is having SOME effect? The British weather does seem to be evolving...

Its much easier to prove events with people having cameras on their mobile phones now. Also internet forums are a good place to find reports, as are websites of local papers.

It is hard enough to get a representative average let alone look at possible changes to this average. Are you in the UK?

[gord]

Added to the fact we've been having some turbulent weather recently with these Atlantic lows queuing up.

Its a case with luck with tornadoes...the more populated the area that one hits in, the more accurate a report can be made.

I think its just one of those things, we've just happened to have more 'high profile' tornados because there has been more witnessess. A lot of tornadoes in the country have gone unnoticed or unsolved.

[Aslkahuna]

I think there are a variety of reasons-first off, the frequency of tornadoes in the UK and Europe is about the same as that in the US but that they are smaller and weaker as a rule and have been underreported in the past. I suspect that with the popularity of US Storm Chase tours in the US among Europeans that we are now seeing more weather savvy Europeans who know what the silly things look like and thus are more likely to photograph and report them. Also, scientific people have also chased in the US and participated in US tornado research and are now taking their lessons learned to the field at home. It's less a matter of more tornadoes and more of a matter of awareness of them that's the answer.

Steve

[Yarrah]

I've heard someone say that the freqeuncy of tornadoes here is even higher then in the US. Only difference is that they usually form over water and aren't as strong as the US tornadoes.

[P.K.]

I've heard someone say that the freqeuncy of tornadoes here is even higher then in the US.

Correct. We have a higher frequency than the USA, and you then have a higher frequency than the UK.

Well if you have more in the USA the chance of strong or large tornadoes is going to increase. The vast majority of USA TNs are weak as well. The largest we have had in recent years is at least 800m across and as high as a T6. We've been collating TN data for the UK since the early 70s (Well not myself as I wasn't born) so I'm not sure that being more interested in the weather has much of an effect, although the odd tv programme on TNs does.

In an article in Weatherwise about 30 years ago, Dr. Tetsuya Fujita noted that the frequency of tornadoes per 10000 sq miles was at least as high as that of the US with the only difference being that they were generally smaller and weaker than in the US and generally underreported.

The most active USA states are higher than the UK, but taking the USA as a whole the UK is more active. (Per 10,000 km^2 was the area I used). As above the generally smaller and weaker comment is dangerous here and seems to have led to the media referring to TNs as "mini-tornadoes" all the time.

[Aslkahuna]

Smaller and weaker doesn't necessarily imply less dangerous-n fact ALL tornadoes are dangerous as there have been deaths due to F0's in fact, a couple of Summers ago there was a person killed in Maine by a DUST DEVIL. One thing about US tornado frequency is that the ones west of the Rockies are severely under reported due to less population and a reluctance in certain NWS offices to verify reports of tornadoes.

Steve

[P.K.]

The same is true here though, and as all the data is collected by volunteers it takes more work to get a decent verification of events. The lack of doppler radar doesn't help either.

[Aslkahuna]

Doppler wouldn't help much in your case since most of your tornadoes are not mesocyclone tornadoes but are rather of the landspout or cold air funnel type which do not show well on Doppler except in rare cases.

Steve

[P.K.]

Every little helps. Would also be interesting to see just how many mesos were detected each year. The 4km radar network doesn't help in this case (It is up to 1km in places but not publically available). Thunderstorms tend to be HP here so its not easy to see storm structure. There are of course occasions when it is possible and some great photos such as these have been taken earlier this year in NI.

[Aslkahuna]

Where Doppler would help you the best would be in characterizing the windfields of those bombing lows in the Channel or the ones that come off the North Atlantic into the Irish Sea.

Steve