Tag Archives: East London

Thunderstorms bring a Holyrood awakening

It was just before 3am that I was awoken by faint rumblings outside. I knew there was a risk of thunder before I’d retired to bed a few hours earlier but I’d discounted the risk along with any thoughts of staying up to watch the referendum results unfold in Scotland.

This radar shot shows the storm just beginning to hit Wanstead. The rain was far heavier to our east. 17.2mm was reported at Laindon, Essex. An observer at Woodford Wells recorded 19.9mm her in about 25 minutes 0310-0335 bst
This radar shot shows the storm just beginning to hit Wanstead. The rain was far heavier to our east. 17.2mm was reported at Laindon, Essex. An observer at Woodford Wells recorded 19.9mm her in about 25 minutes 0310-0335 bst

Lightning then illuminated the room through the gaps in the curtains followed by more rumblings: it’ll pass, I thought. Crash – I grabbed my phone – was this an isolated event? The radar showed a line of slow moving storms moving up from the south. More lightning and loud thunder. My Twitter feed told me it wasn’t going too well for those wanting independence. At this point intensely bright lightning was rapidly followed by one of the loudest claps of thunder I’ve heard around 3.10am. Car alarms were set off – may as well get up I thought… The Inverclyde result was announced – ‘No’, by the narrowest of margins 50.1% to 49.9%. That’s it then, I thought. The lightning and thunder gradually began to fade away with hopes of an independent Scotland, on this night anyway. I glanced at my stats which seemed far less impressive than what was recorded elsewhere: 7.7mm, no big fall in temperature or pressure like previous storms during the summer.

Just a few hours later I walked my younger daughter into school, my bleary eyes struggling to focus – the humid and steamy atmosphere felt more like July than September. Indeed Thursday had been the warmest September 18th since 1997 which, strangely, was the same year that another momentous British event took place: the handover of Hong Kong to China. I remarked to a couple of parents that the only thing that had changed overnight was that Andy Murray will forever be the “Scottish” tennis player after his comment on Twitter.

The forecast advised that there was a continued threat of thunderstorms. It was humid but it didn’t ‘feel’ stormy – though around 2.30pm I could hear the beginning of faint rumblings in the distance.

Clouds above could be seen developing rapidly at 2.30pm
Clouds above could be seen developing rapidly at 2.30pm

I left for work on my scooter at 3pm, carefully watching the sky for any developments all of which seemed to be in the distance. After stopping for petrol in Leytonstone High Road huge drops of rain began splattering the pavement. They were few and far between, however, and the sun defiantly continued to shine. After riding past Stratford I suddenly became aware that the buildings in the distance, past Bow flyover, were gradually beginning to disappear. I pulled in to a turning where Gala Bingo is situated. An electronic noticeboard enquired: “Do you feel lucky?” Not today I thought and retrieved my overtrousers that live under the seat, hastily pulling them on as I watched the impending storm begin to close in.

I continued on and was soon enveloped in the full force of another thunderstorm. Marble-sized hail clattered off my crash helmet while dangerous gusts, caused by wind funneling through the new high rise flats by the Olympic Park, did their best to push me off. Just as I crossed the canal a sheet of rain engulfed me and the drivers to my right. The road in front suddenly turned into a shallow river. I usually ride over the flyover – not today with the torrent of water cascading off the sides.

The 3.15pm storm that flooded large parts of East London. The white area shows where the heaviest rain was
The 3.15pm storm that flooded large parts of East London. The white area shows where the heaviest rain was

By the time I reached Mile End the rain had almost stopped. The City looked fairly dry and on reaching London Bridge the roads were completely dry. The Friday crowds were out in force in Borough Market, enjoying the sunshine and seemingly oblivious to the chaos unfolding just a few miles away in East London. Within 10 minutes of walking into my office Alex Salmond announced his resignation. Another storm: another momentous event! It was another of those coincidental storms that, in my mind, seem to mark momentous events such as the Royal birth last July

I checked the stats of the storm back in Wanstead: 24.5mm  fell  with a peak rate of 76.5mm/hr at 15.47. The storm ended a run of 16 dry days bringing the total for the month up to 33mm – the 24hr total was 30.5mm. The explosive convection of this storm can be seen here. The associated hail and rain brought much flooding to Hackney, Hackney Wick and Leytonstone. This storm seemed to be the result of a convergence line over London between light southerlies to the south and easterlies to the north – the heavy rain was very localised.

Flooding images can be seen on the following links at Dalston, Wanstead Flats, Leytonstone Station, Wick Road. A short clip of flooding at Wick Road can be seen here.

The flooding wasn’t restricted to East London. In Southend water started pouring through the roof of the Dixons theatre though it failed to stop the performance. Shops in London Road were inundated.

http://www.echo-news.co.uk/news/11486080.Fire_crews_receive_100_calls_as_severe_flooding_hits_Southend/

See also:

http://www.echo-news.co.uk/news/local_news/11353521.FLOODING_CHAOS___Southend_Hospital_A_E_evacuated_as_south_Essex_is_battered_by_downpour/?ref=var_0

http://www.echo-news.co.uk/news/11486049.Updated__Flash_flooding_hits_homes_and_businesses/?ref=var_0

 

 

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Summer forecast: barbecues and umbrellas

At the beginning of May I had a look at the March and April stats to try to decipher what the coming summer would be like. The results still suggest that summer will be a mixed bag weather-wise with only brief hot spells interspersed with humid thundery breakdowns and cool, cloudy and showery regimes.

mackerel2The third warmest March-April period since 1799 possibly prompted some weather ‘experts’ to claim that we’re heading for a hot summer. But converse to what the Daily Express told us in April I cannot see any signs of a ‘hottest summer ever’.  And it should be remembered that this rag also warned us that the past winter would see ‘100 days of snow’. In the event I think 100 days of rain was probably more true, and I would like to point out at this juncture that my own winter forecast was hopelessly out, along with many others.

To reach my conclusion on this summer I have used pattern matching of meteorological data for March, April and May stretching back to 1799. The mild and dry weather of March and April has been tempered by the wet May. The mean for the spring season was 11.7C with 116.4mm of rain and 473 hours of sunshine. If you take into account all years that were within +/- 10 per cent of these figures you get the following table.

When considering the data I first extracted the number of similar years by rainfall. Of these I then discounted any that were not within + / 10 per cent of the spring 2014 mean temperature.

The ‘best fit’ years were revealed as 1811, 1828, 1871, 1882, 1912, 1945, 1959 and 1989. Using sun hours similarities this could be narrowed further to 1912, 1945, 1959 and 1989, however it should be noted that I don’t have sun hours data prior to 1881!

As an average this summer could be expressed as:

Mean: 17.3C (about average) Rainfall: 186.1mm (slightly above average) Sunshine: 583hrs (slightly above average)

Or, expressed in probabilities, I concluded the following:

Summer probabilities
Summer probabilities

So from the above you could deduce that the next three months will be average to rather cool, with average to slightly below average rainfall. Sunshine below average.

Trying to predict details over the next 3 months is impossible, but looking at the ‘best fit’ years mentioned above a warm spell happened without fail between the dates June 18th – June 22nd. Other dates to bear in mind for possible fine spells are July 5th, July 12th-15th, July 22nd, August 4th and August 20th.

 

* Taking into account the fact that temperatures in London are up to 1C warmer than they were 100 years ago I have added 1C to mean temperatures before 1915.

** Obviously, in the event of a series of direct hits from thunderstorms, my rainfall estimate could be hopelessly short – a symptom of abundant solar energy at this time of year which creates a ‘noisy’ atmosphere compared with winter.

*** The 1981-2010 average mean for summer in this region is 17.6C, with 144.9mm of rain and 564 hours of sunshine

 

 

 

 

 

Kop this for a singularity

The last time Liverpool won the league in 1990 (by league I mean top tier of English football) the South East enjoyed a mostly dry, warm and sunny summer. A particularly hot spell in August of that year saw the UK high temperature record broken when the mercury reached 37.1C at Cheltenham on August 3rd, a record that stood until 2003.

Since the middle of December last year the weather has been remarkably similar to that football season when the Reds won their 18th league title. Both winters were remarkably mild and stormy with January 1990 seeing the Burns’ Day storm.

90 - 14

The mean temperature this year over the same period, December 13th to April 26th, is just 0.2C cooler than 1989-90, while rainfall is 2.1% greater and sunshine is 2.5% less. A remarkable singularity.

Will history repeat itself come the end of the season and the end of the summer? Up until early Sunday afternoon the stage seemed set. But a slip by Liverpool skipper Steven Gerrard at the end of the first half gifted Demba Ba with a chance that opened the way for Chelsea to complete the double over their title rivals.

LiverpoolSquad1989-1990
The Liverpool squad of the 1989-1990 season won the club’s 18th league title

It must have been agonising for the Kop to watch, 24 years on from the exact same weekend the Reds lifted the title with two games left. The weather that followed that memorable day was dry, sunny and warm with temperatures reaching the mid 20s on many days.

Fast forward two dozen years and the weather looks decidedly unsettled, with frequent showers or longer spells of rain interspersed with sunshine. Though there’s doubtless many twists and turns left I wonder if Reds fans believe their title hopes are going the same way as the change in the weather?

Football’s a funny old game – just like the weather.

An unprecedented climate of confusing stats

‘Worst-ever!’, ‘in living memory’, ‘highest on record!’, ‘unprecedented!’. These phrases, used often by newsreaders on the main networks including Sky and BBC, always set an alarm bell ringing in my head. None more so than weather stories which, with the stormy winter we’ve just had, has been happening almost daily since the middle of December.

Screen shot 2014-03-01 at 02.48.32As the winter has progressed the networks have tried to out do one another with the severity-value of a story. What starts with a reporter gingerly standing by the side of a flooded field within days changes to the reporter, donning a pair of fisherman’s waders, trawling waist-deep through a flooded Berkshire housing estate.

The media also seem to delight in rushing out Met Office data to proclaim these armageddon scenarios before the season is over and the statistics can be properly studied, absorbed and commented upon.

Last summer, I started to build a dataset for my own area – Wanstead. Using local figures from the City of London Cemetery I was able to take the daily series back to 1959. Beyond this I then sourced monthly data for Greenwich, 6 miles away, back to 1881. Using W.A.L Marshall’s A Century of London Weather and Luke Howard’s The Climate of London enabled me to take the series right back to 1797.

The series makes for interesting reading, putting this winter as 6th wettest since 1797. Scientists would say that because my series is only one dataset it cannot be regarded as a ‘catch-all’ for the country overall. But when statements like “England and Wales has had its heaviest rainfall since 1766” are put out by the media it is blatantly not true for the entire country. Just a quick look at the map shows that while parts of south and southeast England have been very wet – other parts of the country have been much less so.

But in this age of 24-hour rolling news the message to anyone who takes the headlines at face value is that this has been the wettest winter ever. You can view the winter mean temperature and rainfall stats here.

winter rainfall

mean temp winter

This wet winter is by no means unique

With flooding in the Somerset Levels dominating the headlines it is easy to get carried away with media hysteria that we are in unprecedented times in terms of rainfall. But as with so many media stories these days you don’t have to look far back in meteorological records to find that we’ve been here before.

The jetstream has been virtually ever present over the UK this winter, driving depression after depression over our isles
The jetstream has been virtually ever present over the UK this winter, driving depression after depression over our isles

Although I base this blog on local figures – two series of stats going back to 1881 and 1959 – it is notable that this particular microclimate has actually been dryer than neighbouring areas, including east Essex where the rain crossing this area often peters out. With such power in the jet stream, however, bands of rain have been pushing right through this winter. Surrey has also been notably wetter, with orographic uplift only partly responsible for the increased wetness. Anyone driving around the M25 will have noticed the flooded fields at the side of the motorway.

It has been mentioned that this winter has been the most cyclonic in recent memory, but you only have to go back to the winter of 2000-01 to find a more cyclonic winter, though that season saw fewer severe gales.

Since the beginning of the meteorological winter on December 1st Wanstead has recorded 235.6mm of rain to February 6th. Considering the 1959 series that’s 7% wetter than the winter of 1989/90 – though this winter is actually 0.9C colder than that season 24 years ago.

Looking at the bigger picture, and with 22 days to go, this winter is currently 7th wettest in the series going back to 1881 – quite a way behind 1915 which saw 343.7mm recorded. Looking at the GFS model out to 9 days, however, there is much more rain to come.

The season so far, in terms of temperature and rainfall, has been notable in that autumn did not really offer any hints as to how winter would unfold. At the beginning of December I would have put the probability of a winter such as we have had so far at 10%. Should the rain continue to fall while the temperature stays mild the probability would fall to 1% – a truly exceptional winter in the same league as 1962/63 – but at the other end of the scale.

After my less than impressive stab at a winter forecast I am a bit loathe to make any more predictions. Trying to predict the weather more than a few days ahead with any detail is impossible. And seasonal forecasting is fraught with difficulty. However, precedent suggests we could be in for a warm and settled March. Indeed, if this year is anything like what followed in 1990 we could be in for a very nice summer. But then again we might not. As Mark Twain said: ‘Climate is what we expect; weather is what we get’.

The storm of July 23, 2013

It was the storm that preceded the hottest day of the year when the temperature briefly touched 34C in Wanstead – that’s higher than the official recognised figure of 33.5C at Heathrow and Northolt.

This image by MeteoX shows the storm right over Wanstead
This image by MeteoX shows the storm right over Wanstead

Earlier people all around town and across the country wilted in the heatwave waiting for news on the royal sprog, many of them ignorant that things were about to go bang. But no matter – it’s days like this they say is good to bury bad news – so the weather, it seems, decided to get in on the act too. The first spots of rain fell on an exhausted crack Sky News commentary team outside Buckingham Palace just before midnight. About the same time reports started coming in of thunder in Canning Town and Poplar – but all went quiet after three flashes. Then 11.58pm reports of rain in Luke Howard’s old haunt – Plaistow. My own ride back from town saw reasonably heavy, if somewhat shortlived, rain in Southwark. Yet by the time I reached Aldgate the ground was dry. Things began to liven up again at 1.30am – distant rumbles of thunder getting closer – further reports of multiple thunder, lightning and heavy rain with hail mixed in at 1.45am. Then, bang, the storm hit Wanstead. I failed to get any footage of the event because of the ambient light washing out every shot. Multiple crashes of loud thunder followed by, at one point, dazzling lightning flashes. You know how close a storm is by counting the seconds between lightning and peal of thunder. At 1.51am I barely counted to one between a dazzling flash and one of the loudest cracks of thunder I’ve heard. Only 6.5mm of rain was recorded, though this fell at a rate of 60mm/hr – the highest rate since I put the meteo live online last November. It doubled the previous highest rate! There followed frequent, distant rumblings of thunder to the east along with copious flashes and occasional bursts of rain. Epping recorded 19mm in two storms at 5am and 6.30am. The thunder and oppressive humidity made sleep difficult. And judging by the number of bleary eyes on the school run this morning I wasn’t alone. The were other storms around London and the UK – a notable one in Brixton precipitated this account on Brixton Buzz. And Steve Brice managed to capture the lightning in Gillingham, Kent. Pershore in Worcestershire recorded over 56mm of rain in 3 hours while lightning damaged rail networks. It was one of the most dazzling displays I can remember – certainly the best since probably 2000 if not before. People often ask me what first got me interested in the weather. Until last night I’d almost forgotten that thunderstorms were one of the main attractions. A night to remember – just like the overnight storms in the Eighties I remember as a lad. Scott Whitehead @wanstead_meteo http://www.wansteadweather.co.uk with thanks to @loveloughton for storm updates The following charts show the cell well. The 2mb pressure drop, the 60mm/hr rainfall rate, the 2C dive in temperature, and the sudden gust of wind Image This pressure drop is also reflected in the temperature fall at the same time: 2C in a matter of minutes. Image temp dropgust

Whatever happened to proper summer thunderstorms?

Is anyone else yearning for a good old-fashioned summer thunderstorm? As we move in to what is traditionally the most thunderstorm-prone month – the Met Office average for this area is three days of thunder – you would be forgiven for thinking that we have plenty to look forward to.

Looking north toward Aldersbrook. The Flats can be very exposed during a thunderstorm
Looking north toward Aldersbrook. Wanstead Flats, a 186 hectare open space that is larger than Hyde Park, can be very exposed during a thunderstorm

It was George II who some time during the 1730s apparently characterised the British summer by saying that it was ‘three fine days and a thunderstorm’.

The reality these days, at least in this part of the country, is quite different. Yes, brief fine spells do still break down – but the classic stormy nights I can remember being kept awake by when I was a lad in the Eighties are now a distant memory. A look back through the records shows that our most thundery month happened in June 1982, when thunder was heard on 13 days. On the 2nd a woman was killed after being struck by lightning while walking in a park in Willesden. More storms followed over the next couple of days and there were three more deaths in the UK caused by lightning. One thunderstorm over Loughton flooded 200 houses, some up to the ground-floor ceiling and at least 12 properties were struck by lightning. One observer recorded 79mm of rain, one and a half times the monthly average, in 90 minutes.

Despite a couple of instances of good potential for thunder this past month has been, so far, completely thunder-free, with all the activity passing well to our east. On June 20-21, there were 235,809 lightning strikes in 24hrs over Germany. To put that into perspective the UK, on a typical ‘thunder day’ in summer, receives up to 10,000 ground strikes although the exceptional day of 24 July 1994 produced 85,000 ground strikes.

The meteo is sited on the Aldersbrook Estate and uploads data to the web every 10 minutes, 24 hours a day
The meteo is sited on the Aldersbrook Estate and uploads data to the web every 10 minutes, 24 hours a day

So what is the potential for thunder in July? Looking back at Wanstead and the surrounding area’s local records the average number of days that thunder was recorded works out as 3.5 – though some years thunder occurred considerably more than others. But to get thunderstorms first we need the ingredients. The classic scenario happens at the end of a short heatwave, a cold front advancing from the west undercuts hot and humid air that has been in occupation for two or three days. If there is sufficient moisture in the upper atmosphere, cumulonimbus clouds will bubble upwards to the base of the stratosphere, and thunderstorms will soon follow.

Apart from the first couple of unsettled days at the beginning of July the above scenario looks unlikely to happen at least in the first half of the month. The North Atlantic Oscillation is predicted to stay positive into July – this spells good news for us as it suggests that the Azores high will dominate our weather, bringing lots of fine and dry conditions. With the jet stream and westerlies being kept just north of Scotland, temperatures should be average to slightly above. It is possible that the high could further dominate as the month goes on. But it is also possible that pressure will start to fall after around the middle of the month. Though it is impossible to predict in detail perhaps a date of around 20th would be the most likely for thunder?

It is too soon to say if the recent trend for a paucity of thunderstorms is just a blip. It could just be another typical variation of the British weather and we will shortly see an upturn in summer thunderstorm activity.

Scott Whitehead
@wanstead_meteo
wansteadweather.co.uk