The decline in thunder days.

[Dami]

I too can remember storms in my child hood going on for most of the night, in fact the best by far was the night/morning we were going on holiday. Was also treated to the best cirrocumulus castellanus (thinks that the name, the cloud like turrets) display by miles when the sun came out. To this day i have never seen such a sky. 

 

Normally, storms followed Hot days, at night. I don't remember having many storms during the day really. (apart from one that struck the school playground when we were outside). 

 

I lived on the coast by the downs, so alot of storms broke up before they got me, or in some cases never reach me at all, but i have seen some amazing storm clouds. If i would have to think, i would say where i am now gets more storms than the coast, but the difference is how bad these storms are. In bedford they seem to be more 10 minute bangs and gone while on the coast they are much longer, much more lightning, heavier rain. Scarey loud storms, when i smoked, we had a wooden hut to smoke in at work and we had the loudest storm. not very nice.

[cyclonic happiness]

I blame it on skies full of cirrostratus, caused by thousands of con trails from aeroplanes. 

 

You just don't seem to be able to get convection like you did in the 80s, it's all stunted by lack of sunshine.

 

Just another symptom of an over-crowded planet.   

 

We don't even get clear blue skies in summer now, just hazy sunshine at best.

[Lauren]

I think it's not so much thundery activity as such that has died off, but more the extremities. My storm diaries from the 90's recorded many times where we had really hot days for maybe a week on end followed by huge overnight MCS that would start at about 7 in the evening and still be rumbling away and dying out on the way to school the next day. We used to get roughly 2 a year or so. Now one of those we haven't had for a very, very long time.

[Lauren]

I blame it on skies full of cirrostratus, caused by thousands of con trails from aeroplanes. 

 

You just don't seem to be able to get convection like you did in the 80s, it's all stunted by lack of sunshine.

 

Just another symptom of an over-crowded planet.   

 

We don't even get clear blue skies in summer now, just hazy sunshine at best.

 

Contrails are just water though, if anything they should help thunderstorms. Plus if that were true places with really high air traffic would see a decline but that's certainly not the case.

[stainesbloke]

Am hoping the lack of 'proper storms' is just a cyclical turn of events, it could well be. As others have stated, heat, or the recent lack of it, must play a part. Gone, for now at least, are the days of a long southerly draw lasting days, sometimes weeks, bringing really hot air to our shores, followed by a nice, slow moving low sat in the SW approaches or Bay of Biscay, with fronts inching in. Now, a plume barely reaches our shores before being smashed east at 100mph by unseasonably deep lows. It's the opposite to winter/snow 'get the cold air in place', we need to get the hot air in place for at least a few days and then chances of memorable storms will increase. Jet stream must play a part too. Perhaps July or August could turn out differently? Live in hope!

[Nick L]

I blame it on skies full of cirrostratus, caused by thousands of con trails from aeroplanes. 

 

You just don't seem to be able to get convection like you did in the 80s, it's all stunted by lack of sunshine.

 

Just another symptom of an over-crowded planet.   

 

We don't even get clear blue skies in summer now, just hazy sunshine at best.

 

So why hasn't the US for example seen a decline in storm activity?

[Captain Shortwave]

Convection wise it has been poor here too but to be honest this seems to be a symptom of the poor positioning of the Azores high, seemingly stuck to our south west offering the worst flow possible in terms of convective activity during the late spring/summer as we can only muster shallow convection which leads to light showers at best or persistent thick cloud at worst.

Events like July 2014 used to be quite common (once or twice a year), but these days it seems to be once every 5 or so years.

2012 seems to be the odd one out over the last several years, the saving grace of having slow moving troughs over the Uk for most of the summer ws that you could actually get good convection going, even if it felt cool/cold at the surface.

[Stargazer]

On the whole I think I'm with MP-R on this one - IMBY at least - so it very much depends on where your backyard happens to be.  After a few poorer than average years in a row, 2014 was the best I can recall for thunder since I moved here in 2002 with thunder heard on 17 days and a couple of spectacular overnight storms - though my records are probably an underestimate as I'm sometimes in a noisy environment anyway so can miss thunder if it isn't loud.  I guess the NW, however, didn't have a good year for thunder last year.

[IanR]

I blame it on skies full of cirrostratus, caused by thousands of con trails from aeroplanes. 

 

 

its a theory I have been thinking about but does seem unlikey, but the weather is very fickle so cant be dissmissed as nonsense  .regarding the usa  it still has lots of storms, but hasn't there been decreases in tornado activity there too ?

 

I know nw england is a main flight path for  transatlantic traffic for much of europe, and the trails on some days cover the whole sky in cirrus, making what should be a hot sunny day into a weak milky affair  , I do believe this *could*  be  a factor and explains why the nw has seen a dramatic reduction in storms

 

 also persistent azores high in the wrong place as its been for most of the spring and summer so far... another possible factor , but why does it just sit in the wrong place for us now for long protracted periods? it wasn't  always like that as seem to be now  

 

but who knows 

Edited June 17, 2015 by IanR

[Nick L]

I just think that the apparent decrease going by *some* stats is not statistically significant enough, and the change isn't over a long enough time period to be illustrative of a more long term and permanent pattern shift.

[cyclonic happiness]

I just think that the apparent decrease going by *some* stats is not statistically significant enough, and the change isn't over a long enough time period to be illustrative of a more long term and permanent pattern shift.

Oh yes, i agree.

 

The weather changed character completely in the summer of 2007, and it hasn't changed back yet. 

[cyclonic happiness]

So why hasn't the US for example seen a decline in storm activity?

Because we're a much smaller area, with much heavier air traffic.   There has been a massive increase in condensation trails over the Midlands and you can physically see storms and convection struggling to get going.

 

It would be great to find some actual proof, but who's looking?

[IanR]

Because we're a much smaller area, with much heavier air traffic.   There has been a massive increase in condensation trails over the Midlands and you can physically see storms and convection struggling to get going.

 

It would be great to find some actual proof, but who's looking?

same here, if you look at the aircraft tracking site, flightlevel there are large numbers of aircraft over the midlands and nw during afteroons, rarely do we get a clear blue azur sky now with hot burning sun like we did a couple of decades ago,  even in a strong summer anticyclone the many many trails merge to form a milky cirrusy  mess, that covers much of the sky limiting the suns power, 

 

also we have to understand what causes thunder in the first place, and its the right atmospheric conditions to cause the air to become very light, unstable and therfore rise rapidly usually through heating,  but what if the air is a bit heavier due to more co2 but without the increase in temps, as seems to be happening, harder for the rapid rising?   then again the continent still gets lots storms ? yes , but they still have heat to fuel them,    just another (unlikely) possibility,   running out of ideas now 

[Nick L]

Perhaps it might be an interesting dissertation/research/PhD topic for someone out there!

Edited June 17, 2015 by Nick L

[J10]

I haven't got stats on this, but last October was very thundery in this neck of the woods.

 

4 or 5 days with a lot of Thunder and Lightning.

[ChezWeather]

Posted this link in the convective thread a few days ago but it might be of interest here.

 

http://www.metoffice.gov.uk/climate/uk/summaries/anomacts

 

You can view the "days of thunder" per month from 2001 to 2010 and lightning strikes per month from 2001 to 2015.

 

You can also compare the days of thunder per month against the average days of thunder from 1971 to 2000.

 

 

[virtualsphere]

I haven't got stats on this, but last October was very thundery in this neck of the woods.

 

4 or 5 days with a lot of Thunder and Lightning.

 

Yes we had a very thundery period here last autumn - 4 thunder days here between 6 - 11th October and a further 2 days on 2nd & 9th November.  Last year was probably the most thundery year I can remember since at least 2000 with thunder heard during 8 months out of 12.    This year hasn't been anywhere near as stormy (only 2 days so far), but overall I think if anything the frequency of storms has increased slightly here since about 2007 - probably because we get a lot of thundery showers from a returning polar maritime SW airstream. Dec 2013 - Jan 2014, and November 2009 were similar periods.   

 

Certainly the frequency of continental plume storms has decreased here though, so while we've heard more thunder it has been from Atlantic lows in the Autumn-Winter period rather than severe summer storms with prolific lightning.  It is unusual to experience severe storms in this area being located close to the west coast though.

[Summer of 95]

There seems to be a lot more of what I call "mid level muck" around these days, especially in warm airmasses in summer. Basically this is a kind of altostratus/altocumulus that looks and seems to form like cumulus/stratocumulus, forming grey sheets across large parts of the sky. Unlike the classic altostratus (that you get with an approaching depression) you can never perceive the sun through it. The altocumulus form is flat with few if any gaps between the ripples, quite unlike castellanus. It seems to me as if humid air masses now have some sort of convection ceiling at around 5-15000ft that prevents Cb cloud developing.

As for the contrails, something definitely changed in the late 90s. There were plenty of planes before then, yet you only saw the pencil lines that soon vanished. Never, ever did you get the lines or sheets of pseudo-cirrostratus that dim the sun and last hours. Either the composition of the exhaust has changed, or that of the air at that level has. In fact the contrails problem seemed to peak between 2007-12 here, it's been a bit less prevalent since though it certainly hasn't gone away (this week has been terrible for it, and for mid level muck). I noticed a while ago that cumulus doesn't bubble up as readily when lots of contrails are present. BTW it doesn't matter whether you live near a flight path or not, a lot of the contrails pollution forms miles away, often out in the Atlantic. It regularly blows in from the west on summer afternoons, while you can see planes overhead forming nothing.

[Nick L]

There seems to be a lot more of what I call "mid level muck" around these days, especially in warm airmasses in summer. Basically this is a kind of altostratus/altocumulus that looks and seems to form like cumulus/stratocumulus, forming grey sheets across large parts of the sky. Unlike the classic altostratus (that you get with an approaching depression) you can never perceive the sun through it. The altocumulus form is flat with few if any gaps between the ripples, quite unlike castellanus. It seems to me as if humid air masses now have some sort of convection ceiling at around 5-15000ft that prevents Cb cloud developing.

As for the contrails, something definitely changed in the late 90s. There were plenty of planes before then, yet you only saw the pencil lines that soon vanished. Never, ever did you get the lines or sheets of pseudo-cirrostratus that dim the sun and last hours. Either the composition of the exhaust has changed, or that of the air at that level has. In fact the contrails problem seemed to peak between 2007-12 here, it's been a bit less prevalent since though it certainly hasn't gone away (this week has been terrible for it, and for mid level muck). I noticed a while ago that cumulus doesn't bubble up as readily when lots of contrails are present. BTW it doesn't matter whether you live near a flight path or not, a lot of the contrails pollution forms miles away, often out in the Atlantic. It regularly blows in from the west on summer afternoons, while you can see planes overhead forming nothing.

 

I'm not sure whether the composition of the exhaust would make any difference, as contrails are simply water, the exhaust just provides the nuclei for the water vapour to condense onto.

 

Again, this is another interesting point for further study!

[knocker]

Jet contrails affect surface temperatures

 

High in the sky where the cirrus ice crystal clouds form, jet contrails draw their crisscross patterns. Now researchers have found that these elevated ice cloud trails can influence temperatures on the ground and affect local climate, according to a team of Penn State geographers.

 

http://ekaweb02.eurekalert.org/pub_releases/2015-06/ps-jca061815.php

[johnholmes]

Oh please don't start that again?

[Weather-history]

I have had a look at my weather diaries and it struck me how little I mention thunder in any October entries. Infact the last October thunderstorm was back in 1993, which I remember well.

Edited June 19, 2015 by Weather-history

[Weather-history]

I remember a storm in October 2013 hitting Manchester. It wasn't a bad one for the time of year:

 

 

Untitled.jpg

I remember that one, I couldn't remember if it was late October or early November. October thunderstorms, twenty years apart and virtually nothing in between.

[Lauren]

If the contrails thing were true regarding thunderstorm formation we'd see a strong pattern of less storms under busy air corridors and vice versa, but as far as I'm aware this simply isn't true.

[IanR]

If the contrails thing were true regarding thunderstorm formation we'd see a strong pattern of less storms under busy air corridors and vice versa, but as far as I'm aware this simply isn't true.

its true for the north west,  the continent still has that most important ingriedient ,heat,

 

its only one of many possible theories

Edited June 20, 2015 by IanR