Netweather Community Investigation Into Lack Of Thunderstorms...

[Robbie Garrett]

Hello All,

Would be good to keep discussion on this separate from the Severe Weather Discussion Topic. (Sorry MODS if this is probably the wrong place)

Sorry if I have missed any quotes, no offence it's midnight

thanks for that, for anyone interested, I've gone through the stats, and have come up with the following conclusion.........

MY BRAIN JUST DIED READING ALL THAT DATA!!

...just kidding, so if I've read the data correctly for the summer month period (may to august) and in summary

1970's - generally positive NAO

1980's - positive/neutral NAO's May's....negative NAO June's.... strongly positive NAO's July's....negative/neutral August's

1990's - negative NAO's May, June, & July months.....strongly positive NAO' Augusts

2000's - neutral NAO's May months, negative NAO's June, July & August months

bare in mind, I've average the data per decade...I'd have to dig a lot deeper to for individual years...... it'll be interesting to correlate that data to the amount of thunderstorms in any given summer to work out the relationship, if any.......Anyhoos after all that number crunching, I need a stiff drink & two aspirin for the brain ache....lol

That would probably tie in with how I remember my Childhood, Lauren and Harry and many others have also elaborated on this.

August, September, October 1997 where some of the most scariest months of my life. It brings back a lot of memories. A quick check shows those months where pretty much positive NAO (except Oct) 1999 was also a good year, and that kinda shows with the positive NAO.

I think you've probably hit the nail on the head here AJ.

The only time in the last 10 years that was up there with the best was June 2005, and July 2006. NAO Positive/Neutral in these occasions.

One of these this Summer would be nice.

I also remember 07th July 2009 being a fairly good day, that was the last time I remember a proper Summer Storm. The one last year being the only exception, but they where not even as intense.

I might have got it a bit I have a-r-s-e about-face actually, I need to re-check the figures...In my idea, a positive NAO would equate to more atlantic influence and less continental (i.e thundery) influence...oh well, my brain hurts and I'm tired....lol

I guess it all depends on where you live as to how the NAO affects frequency of storms (if indeed it does)...For the south-east a more neutral NAO would be ideal I guess, for more western/north western parts, a weakly negative NAO would be ideal....I think

Well the months with the most thundery activity seem to have a more neutral NAO come to look at it..

June 2005 for example had -0.05 NAO, It had 20 active Thunderstorm days. August 1997 had a NAO of 0.34 and from what I remember that wiped out Southern England on occasions. I suspect finely balanced conditions may be more crucial for Thunderstorms??

I have emailed the metoffice looking for 1990s Storm data. Might be interesting to have a look at this and see what we can find.

April 2012 was quite neutral and that provided a lot of Thunderstorms for me. As you say it may be more influential depending where you live. Also the May 2001 MCS that was mentioned in the link you gave me earlier had a NEUTRAL NAO. April 0.00 May - -0.02

So with a negative NAO, there is less likely to be Thunderstorms because there is more cooler air and a southerly tracking jetstream, but with a positive NAO you have more warmer air further north as the jetstream is likely to be over the top or the the north. With something neutral you have equal amounts of cooler air and equal amounts of warm/moist air allowing strong intense thunderstorms??

Am I on too something? LOL!!

Edit: 2005, had a lot of NEUTRAL NAO months. 2005 1.52 -0.06 -1.83 -0.30 -1.25 -0.05 -0.51 0.37 0.63 -0.98 -0.31 -0.44 - and that had the busiest Atlantic Hurricane Season on record.

edit.. someone could make a topic on this

Edited May 29, 2012 by Robbie Garrett

[ZONE 51]

Ok, for the southeast you proberly remember the days(mostly 90s early 2000s) when we would be wondering why we don't get snow anymore, the years we would not see anything but mild weather, and through those same years we where getting imported thunderstorms from the near continent during spring and summer, there could be a connection with this i think, the storms in north France for example over the last few years have been taking a route as close as the channel, and then moving a way with a great swing east. The MCS storm would move across the Southeast and up through the Midlands and finally into the Northeast, sometimes stalling and turning into a lot of rainfall from the left over storms, for the West there would be fronts and troughs slow moving developing storms, the convergence zones in the Southwest used to happen quite often, and also there seems to be the lack of storms moving in from the west to the Southeast, cold fronts from the west or sw into the heat, there where times when even weak cold fronts produced spectactular lightning shows on the western horizon, this during a heatwave.

I won't be posting any technical info today, i am looking into this and others.

If we take a look at how long range forecasting is done and put this idea in as something to look at for the lack of storms, then this would help, what is happening is a large player in the weather systems, the synoptics, NAO/La nina/El nino, and with all this the Jet stream pattern.

ESS

Edited May 29, 2012 by ElectricSnowStorm

[Aaron]

I've definitely noticed that during periods of high thunderstorm activity, snow was less common and now we have had a few cold winters (this past winter was 'average' for England and Wales but with temperatures below -15C) thunderstorm activity appears to be dwindling, especially in the form if continental imports.. probably no science to back this up at all but it's something I personally notice.

[ZONE 51]

I've definitely noticed that during periods of high thunderstorm activity, snow was less common and now we have had a few cold winters (this past winter was 'average' for England and Wales but with temperatures below -15C) thunderstorm activity appears to be dwindling, especially in the form if continental imports.. probably no science to back this up at all but it's something I personally notice.

There will always be a scientific answer, even if it takes a long time to work it out, sometimes you need years to display a pattern, it's only since we have had snowy spells every winter over the last few years especially from from feb2009 that i started to see something, i realised at the same time we are missing our imported thunderstorms, the last being july or august 2009, can't remember, they where our last night-time storms and were imported, with nothing but the odd flash on the horizon since then.

Also to note is the drier then average months that led to the drought, so it could be some kind of large scale blocking pattern.

"3 fine days and a thunderstorm" was something said often through the summer months!

My main focus is on the lack of imported storms.

[Methuselah]

IMO, it's all down to synoptics: over the previous two summers, HPs have seldom been allowed to migrate northeastward enough to allow Spanish plume-like conditions to properly develop. The result being, at least as I see it, that Continental 'heat lows' have not had sufficient time to migrate over the UK...Boring innit!

[4wd]

Can't say I've noticed any thunderstorm deficit here to be honest.

Last year one blew my modem for starters.

You do get considerable year to year variation, but it doesn't have to be all connected with hot humid air from Europe.

We often get quite nasty little storms running down the North Sea coast which readily have lightning involved even when it's so cold that it can be snowing.

[Methuselah]

Can't say I've noticed any thunderstorm deficit here to be honest.

Last year one blew my modem for starters.

You do get considerable year to year variation, but it doesn't have to be all connected with hot humid air from Europe.

We often get quite nasty little storms running down the North Sea coast which readily have lightning involved even when it's so cold that it can be snowing.

Good point.

It could be simply that, as any negative anomaly has been more prominent in the South East, more folks have noticed it?

[Neilsouth]

Netweather Community Investigation Into Lack Of Thunderstorms...

should be renamed into

Netweather Community Investigation Into Lack Of French Imports

That's generally the problem as there hasn't been a decrease in storms in the uk it's just the location has changed

[Robbie Garrett]

Netweather Community Investigation Into Lack Of Thunderstorms...

should be renamed into

Netweather Community Investigation Into Lack Of French Imports

That's generally the problem as there hasn't been a decrease in storms in the uk it's just the location has changed

Good point.

It could be simply that, as any negative anomaly has been more prominent in the South East, more folks have noticed it?

The south east has always got storms, but even lately we have had hardly any... except April which brought quite a lot. This had a neutral NAO, and was predominately from Northerlies.

As someone has said, the location of where imports track has been poor... but this is down to direction of winds and of course synoptic which go hand in hand.

Imports are the best kind of storms, especially the MCS.

[Tim B]

I suppose it depends where you are, up where I am the simple explanation is that every summer starting with 2007 to the present day has been terrible with none of the prolonged heatwaves that are required for proper storms. 2006 was the last year when I saw decent thunderstorms here and there was a good few of them, but that year was scorching hot from May to October with only a few cool periods.

Everyone flocks to the convective discussion threads whenever we get these mini heatwaves but the stone cold truth is they simply aren't good enough for proper thunderstorms as there isn't time for sufficient energy to build up except in rare situations where a plume is involved, you aren't going to get tropical thunderstorms out of just one week of hot weather any more than you are going to get 400 bhp from a 1.2 corsa engine.

What we need is a prolonged spell of very hot weather, say a month to six weeks, then for it to break down with a cold front passing through. This would give us a widespread outbreak of powerful storms.

[Robbie Garrett]

Just spoke to the MetOffice they will give me ATD from 1990-2001 for £150, this being monthly data. I have the email address of the person who you can contact but I cannot afford £150 just for 12 x 10 maps of ATD data.

[Aaron]

In an average here we should get 7 - 9 days of thunder a year, but so far this year I've only heard thunder once. Last year, probably 4 or 5 times. I don't think imports ever make it up here, the best storms here are almost always home grown, like 15th of June 2009 - still yet to beat this storm for pure intensity.

I just want a repeat of 2004 and 2005 - they were great storm years.

Edited May 30, 2012 by Aaron

[Phil UK]

I blame the Daily Mail. Everyone else does.

Otherwise I blame the Europeans. If this were the Euroweather Storm Contest, we would get 'Nul storms'. Even Jedward with their cumulonimbus top style haircuts would do better. Spanish Plume won't deliver anymore. Pfft!

Phil.

[IanR]

The GW zealots told us a decade or 2 ago that storms would be more common and be more intense, the opposite is happening

[Methuselah]

The GW zealots told us a decade or 2 ago that storms would be more common and be more intense, the opposite is happening

Worldwide?

[IanR]

No, the UK

[ZONE 51]

I am focusing on the lack of imported storms rather then home growns, we are getting home grown storms and we should always get them, for example sea/land breeze convergence is something that will happen, the lay of the land-hills and mountains helping build up storms, but the locations of where the storms form may have changed and this would be looked at to, has the land/sea breezes been acting any different? any change in the usual locations of where the storms form due to convergence?.

Imported storms don't turn up anymore, these became rare after summer 2009, they were part of our summer, they are rare now, the last few years something has changed, and this change has come in the form of more severe cold snaps and proper snowfall on each winter over the last few years, for the Southeast to get these cold spells on at least one month 4 winters in a row is unusual, feb09, dec2010, jan2011, feb2012, and to have a proper snowfall on winters in a row like that here is unusual to, and that is what has been happening, and to this i believe there is a connection with the lack of imported thunderstorms, we have of course tapped into some thundery plumes ,but without the storms, without the MCS, is it normal to be watching all the storms over on the continent just veer off east everytime? it never used to do that, yes there were times when they didn't happen years a go to, but then we would get at least one or two thundery nights throughout the spring/summer months, and night lightning displays not seen here since late summer09.

How does the winter blocking patterns relate to the lack of imported storms? if we had an atlantic dominated winter that was mild with no cold and snowy spells of any significance then how would this affect the thunderstorm season? would there be more imported storms? i ask myself these questions, and then i think about the NAO, the La Nina/El Nino patterns, whats the Jet stream up to, where is it now, how is the drought relating to all this..

So a lot for me to have a look at closely, and i'm sure some of you would place your own theorys on the table and we can take a look at them! This summer and the following winter could help set my theory in place!

Edited May 31, 2012 by ElectricSnowStorm

[Robbie Garrett]

I am focusing on the lack of imported storms rather then home growns, we are getting home grown storms and we should always get them, for example sea/land breeze convergence is something that will happen, the lay of the land-hills and mountains helping build up storms, but the locations of where the storms form may have changed and this would be looked at to, has the land/sea breezes been acting any different? any change in the usual locations of where the storms form due to convergence?.

Imported storms don't turn up anymore, these became rare after summer 2009, they were part of our summer, they are rare now, the last few years something has changed, and this change has come in the form of more severe cold snaps and proper snowfall on each winter over the last few years, for the Southeast to get these cold spells on at least one month 4 winters in a row is unusual, feb09, dec2010, jan2011, feb2012, and to have a proper snowfall on winters in a row like that here is unusual to, and that is what has been happening, and to this i believe there is a connection with the lack of imported thunderstorms, we have of course tapped into some thundery plumes ,but without the storms, without the MCS, is it normal to be watching all the storms over on the continent just veer off east everytime? it never used to do that, yes there were times when they didn't happen years a go to, but then we would get at least one or two thundery nights throughout the spring/summer months, and night lightning displays not seen here since late summer09.

How does the winter blocking patterns relate to the lack of imported storms? if we had an atlantic dominated winter that was mild with no cold and snowy spells of any significance then how would this affect the thunderstorm season? would there be more imported storms? i ask myself these questions, and then i think about the NAO, the La Nina/El Nino patterns, whats the Jet stream up to, where is it now, how is the drought relating to all this..

So a lot for me to have a look at closely, and i'm sure some of you would place your own theorys on the table and we can take a look at them! This summer and the following winter could help set my theory in place!

The only connection I can see is that a southerly tracking jet-stream relates to a generally negative NAO, and this is of course means northern blocking with no chance of the Euro high being able to build without problem.. any high that does build is flat and means that all the storms head east not nne or north. Probably why areas of Spain and France have hit record temperatures the last few years and we've only luckily managed to get one blast end of June last year with the Plume... and then even with this the storms didn't want to form.

Maybe it's the Atlantic?? Maybe it's frontal waves are not as strong as they used to be?

[Methuselah]

On the other hand, maybe it's just natural variation? I'm sure that there must have been similar decreases/increases in thunderstorm activity (over the SE half of the UK) in the past...The jet-stream meanders...Mr D?

[ZONE 51]

The only connection I can see is that a southerly tracking jet-stream relates to a generally negative NAO, and this is of course means northern blocking with no chance of the Euro high being able to build without problem.. any high that does build is flat and means that all the storms head east not nne or north. Probably why areas of Spain and France have hit record temperatures the last few years and we've only luckily managed to get one blast end of June last year with the Plume... and then even with this the storms didn't want to form.

Maybe it's the Atlantic?? Maybe it's frontal waves are not as strong as they used to be?

Or it could be low Solar activity, which causes more blocking and affects the Jet Stream which effects the high pressure patterns/positioning? I am expecting the return of imported storms this summer, and this following winter could be different to the last few-if there is a relation to the winter weather and lack of imported storms, so the end of next winter could hold clues to my theory, i will pin this.. trust! Edited June 1, 2012 by ElectricSnowStorm

[ZONE 51]

On the other hand, maybe it's just natural variation? I'm sure that there must have been similar decreases/increases in thunderstorm activity (over the SE half of the UK) in the past...The jet-stream meanders...Mr D?

It could be, and a frustrating one i have to say! i just hope that it re-variates itself soon..

Have we asked anyone over the pond? wonder how they view this, has there been an increase in storms over the channel or a decrease, any track change.. at least we know not to storm watch from that direction, we know where they are going!

Edited June 1, 2012 by ElectricSnowStorm

[IanR]

I wonder if some secret experimental stuff is going on like cloud seeding or spraying sun reflecting particles (aluminium sulphate?) in the atmosphere , I have heard China and Russia are up to such tricks, and what about HAAR, could this be an explaination I wonder

[weatherobsuk]

One possibility unexplored (yet historically has had effects on climatic weather) is the Volcanic activity associated with Eyjaf and the short outburst of Grimsvotn, not exceptionally large in VEI terms but combine the Eritrean eruption of Nabro last year which erupted massive amounts of outgassing & SO2 which, due to it's geopolitical location, was only recorded by satellites and a handful of ground scientists.

It's been known since the Laki eruption & Pinatubo that such large eruptions have had slight climatical effects on temperature, maybe this is what we are starting to see now in the northern hemisphere?

[IanR]

Sorry, I meant HAARP which is something I have only recently heard about , been reading up various articles on this subject , but there doesn't seem any proof it affect the weather in any way.

[ZONE 51]

One possibility unexplored (yet historically has had effects on climatic weather) is the Volcanic activity associated with Eyjaf and the short outburst of Grimsvotn, not exceptionally large in VEI terms but combine the Eritrean eruption of Nabro last year which erupted massive amounts of outgassing & SO2 which, due to it's geopolitical location, was only recorded by satellites and a handful of ground scientists.

It's been known since the Laki eruption & Pinatubo that such large eruptions have had slight climatical effects on temperature, maybe this is what we are starting to see now in the northern hemisphere?

Interesting thought, i really think that it is something bigger than small eruptions, or it could be a combination of things, i think there is a connection with winter patterns and less occurences of imported thunderstorms or hot plumes.

Looking at Southeast England we have seen an increase in snowfall, especially across inland areas, and sharper cold snaps and some have been severe and pronlonged, and at the same time we are experiencing a lack of imported thunderstorms, the track of those storms has changed, we could say that for example the 1950s saw severe cold winters to, but i don't know if there was a lack of imported thundery weather? what we have seen is a few winters in a row with snowfall falling and staying on the ground in my areas and also the very cold periods, and to me this is unusual, we have had a low solar phase during these last few winters, which is said to cause an increase in blocking patterns, it changes the Jet stream pattern, the solar activity is increasing from a low phase, it's not easy to explain but i see a return to those imported thundery plumes this summer, and looking at large scale signals i see a big change to our pattern.

Edited June 9, 2012 by ElectricSnowStorm