Supercell 89

Disant rumble just heard in Reading

Heavy shower here now. Hoping with any luck we may get at least a bolt of lightning at some point

Interesting echo shapes from those showers/storms in the channel, Im sure the one over IOW is splitting away

Some nice cells firing up north east of here now its passed over.

Severe drizzle kicking in here now MD issued get everybody indoors In all seriousness i wouldn't be surprised if this cluster explodes into life as it moves northward

Lol that's my reaction as well. Still annoyed about last night although it was a long shot

Slightly off topic but out of interest has there been an MCS hit central southern England in recent times? Im sure there was one in the 90's as i remember when I lived in Hampshire we had a cracking storm that went on for several hours one summer

Ah cheers Nick! Yeah me and my housemate had been debating whether or not it was it certainly looks it. Really hope that monster makes it to reading, yet to experience one in the UK and in an attic its going to be immense!

Is that a developing MCS over central France slowly nudging it's way northward? Looks incredibly potent though i doubt if it will make it across the channel

Sky full of Alto Cu here in Reading, has been full of a mixture of towering Cu and Alto Cu most the afternoon but the strong breeze has dropped slightly in the last hour, still got my fingers crossed for later

Had an interesting heavy shower in Reading. The convection was pretty organised, with a clear inflow into the main cell and also with a brief area of rotation. Had some near pea sized hail to boot as well, wherever is south east of here is going to get a pounding in the next half hour.

Just posted this in the Summer 2014 thread but the latest PDO values for April and we've gone into firm positive PDO territory now with the latest value coming in at 1.12 http://jisao.washington.edu/pdo/PDO.latest

Is it me or is there still positive anomalies shown down to the surface on that chart? As to me it looks like the +ve values are just starting to be flushed down to the troposphere before the negative values take their place, so we could yet still have another month or so of the +QBO's influence? (I am trying to still familiarise myself with these charts) Comparing this year with 1972 though, 1972 had a -PDO for the majority of the summer like 2009, in fact it was more strongly negative. The latest PDO values are out and its strengthened to 1.12 during April making it the highest value its been since July 2006. If it stays on this course I think this may be able to counter the -QBO during the summer but if it weakens to more neutral values then I would favour more cooler and unsettled conditions prevailing. PDO link http://jisao.washington.edu/pdo/PDO.latest

The latest QBO data has come in and shows that the +QBO is now well on the decline with last months reading coming in at 7.15 a decline from 11.72. So I would expect a transition to a weak -ve stage during June very much like 2009. Also i've been trying to find some information on the chase of phase state of the QBO as i'm sure i read on here once, possibly courtesy of GP that these phase changes have an impact upon the troposphere for a time and also that March 2013 was one example of that but again I can't find anything so not sure if its me going crazy or if I misread something at some point, don't know if anyone else knows? The PDO looks like its starting to turn more positive again judging by the latest SST anomalies and with the pacific looking more favourably towards a weak El Nino event this could help us possibly see the PDO remain positive for the summer which puts us in a much more favourable position to 2009 when the PDO was weakly negative throughout the majority of the summer. However we will have to see if this ENSO event really takes off in the next few weeks. So at the moment I still think a warm dry summer is likely for the UK especially if we can keep a positive PDO phase throughout.

Very Interesting read, probably the best scientific article i've read about climate change. I had wondered if the negative PDO/ La Nina had helped peg the global temperature back. If this is the case its very likely it would have helped nudge the global temperature upwards in its positive PDO/El Nino phase, along with additional manmade factors.

Flash directly overhead and cracking boom clap of thunder

Had one rumble of thunder in Reading. Heavy rain now not heard anything in a while

Yeah sorry it was my personal view of it from the South Devon as we had a very warm june followed by a cold July like most of the UK but the August was coolish but the further east you went it was more near average and it was above average for the South East as they had frequent S/SE flows off the continent if I remember rightly but I do think this was El Nino's influence kicking in as you say. The -QBO and the PDO combination I think were the key points to that summer being unsettled during July to early August, interestingly 1991 and 2009 were quite similar in respect of ENSO, QBO but the PDO turned positive more quickly and was positive during the August. Looking at this year, again those two years are pretty close, especially 1991 however we haven't had a -PDO since late last year and it was very positive during March so we are in a much better starting position for this summer than those two which had strong -PDO springs. Looking at the SST's in the Northern Pacific they don't seem to have been showing a strong +PDO pattern the last few weeks so its possible we may see a return to more neutral conditions for a time or perhaps even into weak -PDO territory. The ENSO conditions remain mostly positive with warm SST's across the pacific except for S.America but they have decreased since early April. I've been watching it since January and it seems to be building in waves with each burst of low level westerly winds from Indonesia. Theres currently been another build up of westerly low level winds over Indonesia, coupled with the Kelvin wave which is now coming to the surface across S.America we could see another increase in STT's, particularly around S.America. If I was to be really bold i'd say we may see a quick transition to weak El Nino during the next month or so but this is the first time i've routinely watched a possible ENSO event build so I'm certainly no expert. So in regards to this summer I think the next few weeks may paint a better picture for where we may be heading

Nice cell firing up to my north east has done very quickly as well. Thinking it may all kick of just to the east of here later today if it does

Very lovely loud and crackly storm just passed through Reading very nice to wake up to

Just seen this thread after posting my early summer thoughts and clogging up the summer 2014 thread but i thought they be more suited to this thread instead. But I've never really done this before but will give it a go see how it pans out In regards to this summer, I've been doing a lot of background reading into signals such as the QBO, PDO and keeping an eye on the ENSO conditions as well and I have a strong hunch that this summer will be warmer and drier than average if and only if this supposed El Nino is able to get in gear in time. So I decided to give it a go and put together an amateur outlook to summer 2014. Looking into just the QBO & PDO. The QBO it looks to be turning into its negative phase most likely around June possibly July which isn't normally favourable for warm dry conditions during summer. The last time we saw a switch from negative to positive during summer was 2011 and 2009 before that, in which both also featured negative PDO phases. The negative PDO also enhances a cool wet pattern for the UK with a southerly tracking jet. Now 2013 saw a -PDO pattern although it was weaker than in previous summers although it did strengthen towards August but we also saw a pretty strong +QBO event which peaked during July and August. A quiet MJO and low SST's around the UK both I think also contributed to us having a very warm July in particular, with the strengthening negative PDO and a more active MJO allowing for August to be more mobile and cooler. (Of course I'm not expert). The PDO has been positive the last few months which by no means guarantees a nice summer, however if this El Nino event is able to take off then it could encourage a continued positive, perhaps a strongly positive PDO during the summer this year, which will hopefully mean the jet stream will move northwards as it should do during the summer instead of tracking southwards. When looking at other years to match the introduction of a Negative QBO during the summer months to this year I found the following years :- 1967 1976 1981 1983 1986 1988 1991 2009 A very interesting mix especially '76 and '83. From that list we have; 2 Very Warm Summers (1976, 1983) 1 Warm Summer (1991) 1 Average Summer (1967) 4 Cool Summers (1981,1986,1988 & 2009) The composite I got from all of those years was interestingly quite good, although the high pressure anomaly is quite weak. http://www.esrl.noaa...mit=Create Plot By taking out the La Nina year (1988 as its very unlikely to happen) and those with -PDO patterns throughout the summer (1967,1991 and 2009) we get the following composite; http://www.esrl.noaa...mit=Create Plot This time we can see a much stronger high pressure anomaly right over the UK and North-Western Europe. Just for interest if we take the -PDO years and the La Nina summer we get the following composite; http://www.esrl.noaa...mit=Create Plot So my thoughts are if we can keep a positive PDO throughout the summer with an El Nino and the QBO transition is slow or the negative QBO weak then we could get a pleasant summer with more lengthy warm dry spells of weather .

Last summer was wonderful, particularly the July. Having moved from South Devon to Berkshire, where its rare to reach above 25c let alone reach 30c having 7 days of temperatures of 29c and above was fantastic! and something which i've never experienced before in the UK. In regards to this summer, I've been doing a lot of background reading into signals such as the QBO, PDO and keeping an eye on the ENSO conditions and I have a strong hunch that this summer will be warmer and drier than average if and only if this El Nino is able to get in gear in time. So I decided to give it a go and put together an amateur outlook to summer 2014. Looking more in depth other signals and patterns, the QBO it looks to be turning into its negative phase most likely around June possibly July which isn't normally favourable for warm dry conditions during summer. The last time we saw a switch from negative to positive during summer was 2011 and 2009 before that, in which both featured negative PDO phases. The negative PDO also enhances a cool wet pattern for the UK with a southerly tracking jet. Now 2013 saw a -PDO pattern although it was weaker than in previous summers although it did strengthen towards August but we also saw a pretty strong +QBO event which peaked during July and August which coupled with low SST's around the UK I think helped high pressure to ridge across the UK for those three weeks. Unlike 2009 and 2011 the PDO has been positive the last few months which by no means guarantees a nice summer, however if this El Nino event is able to take off then it could encourage a more positive perhaps a strongly positive PDO during the summer this year, which will hopefully mean the jet stream will move northwards as it should do during the summer instead of tracking southwards. When looking at other years to match this type of pattern I managed to the following:- 1967 1976 1981 1983 1986 1988 1991 2009 A very interesting mix especially '76 and '83. From that list we have; 2 Very Warm Summers (1976, 1983) 1 Warm Summer (1991) 1 Average Summer (1967) 4 Cool Summers (1981,1986,1988 & 2009) The composite I got from all of those years was interestingly quite good, although the high pressure anomaly is quite weak. http://www.esrl.noaa.gov/psd/cgi-bin/data/composites/comp.pl?var=Geopotential+Height&level=1000mb&mon1=5&mon2=7&iy=1967&iy=1976&iy=1981&iy=1983&iy=1986&iy=1988&iy=1991&iy=2009&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&ipos%5B1%5D=&ipos%5B2%5D=&ineg%5B1%5D=&ineg%5B2%5D=&timefile0=&tstype=0&timefile1=&value=&typeval=1&compval=1&lag=0&labelc=Color&labels=Shaded&type=2&scale=100&labelcon=1&switch=0&cint=&lowr=&highr=&proj=ALL&xlat1=0&xlat2=90&xlon1=0&xlon2=360&custproj=Northern+Hemisphere+Polar+Stereographic&level1=1000mb&level2=10mb&Submit=Create+Plot By taking out the La Nina year (1988) and those with -PDO patterns throughout the summer (1967,1991 and 2009) we get the following composite; http://www.esrl.noaa.gov/psd/cgi-bin/data/composites/comp.pl?var=Geopotential+Height&level=1000mb&mon1=5&mon2=7&iy=&iy=1976&iy=1981&iy=1983&iy=1986&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&ipos%5B1%5D=&ipos%5B2%5D=&ineg%5B1%5D=&ineg%5B2%5D=&timefile0=&tstype=0&timefile1=&value=&typeval=1&compval=1&lag=0&labelc=Color&labels=Shaded&type=2&scale=100&labelcon=1&switch=0&cint=&lowr=&highr=&proj=ALL&xlat1=0&xlat2=90&xlon1=0&xlon2=360&custproj=Northern+Hemisphere+Polar+Stereographic&level1=1000mb&level2=10mb&Submit=Create+Plot This time we can see a much stronger high pressure anomaly right over the UK and North-Western Europe. Just for interest if we take the -PDO years and the La Nina summer we get the following composite; http://www.esrl.noaa.gov/psd/cgi-bin/data/composites/comp.pl?var=Geopotential+Height&level=1000mb&mon1=5&mon2=7&iy=1967&iy=&iy=&iy=&iy=&iy=1988&iy=1991&iy=2009&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&ipos%5B1%5D=&ipos%5B2%5D=&ineg%5B1%5D=&ineg%5B2%5D=&timefile0=&tstype=0&timefile1=&value=&typeval=1&compval=1&lag=0&labelc=Color&labels=Shaded&type=2&scale=100&labelcon=1&switch=0&cint=&lowr=&highr=&proj=ALL&xlat1=0&xlat2=90&xlon1=0&xlon2=360&custproj=Northern+Hemisphere+Polar+Stereographic&level1=1000mb&level2=10mb&Submit=Create+Plot So my thoughts are if we can keep a positive PDO throughout the summer with an El Nino and the QBO transition is slow or the negative QBO weak then we should get a pleasant summer with more lengthy warm dry spells of weather

The odd sleety blob coming down in the rain over Reading currently. Hoping we catch something overnight when the temp drops a bit more

Just had the lights flicker followed almost instantly by a clap of Thunder here in Reading, very dark to our North

That cell that's just gone over Portsmouth looks like it had some rotation on it briefly