Category Archives: thunderstorm

Thunderstorm: May 29th 2018

Posts about thunderstorms are usually few and far between – the average number of thunderstorms in this part of the UK in a summer month (July) is just 3.5.

So experiencing four in four days must be very rare; the record for thunderstorms in a month is 12 in June 1982 though I’ve no idea how many of these were on consecutive days.

While the storms over the weekend were all about lightning this one was all about rain and loud thunder. Tuesday, May 29th, started cloudy and dull with some light rain. I was expecting some rain but it lingered and became heavier at 11.30am before turning torrential at 1pm, going against forecasts from BBC and Met Office – the trough was a lot further north than modelled. I pointed this out to the UKMO to be told that a yellow warning was in place for the whole SE region.

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The bulk of the rain fell between 1pm and 2pm
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A marked drop in pressure coincided with a bright flash of lightning that was almost instantly followed by thunder that was as loud as cannon fire

Some 26.5mm fell in just over two hours bringing lots of surface water and flash floods around Leyton and Walthamstow. At 1pm, while driving in this area, a bright flash was quickly followed by cannon-like thunder. A further fall in the early hours brought the 09-09 total rainfall to 29.8mm, the 5th greatest May fall since 1959.

With the storm the previous evening the 48hr rainfall total was 40mm!

In the neighbouring borough of Barking and Dagenham it was reported that lightning struck a chimney which caused a fire in a terraced house in Rush Green at 2pm.

Local media pick up the story here, here and here.

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The position of the storm around the time of the loudest thunder
South acess
South Access Road in Walthamstow suffered flash flooding as drains failed to cope with the volume of rainfall
trough
The trough on this FAX chart suggested the heaviest rain would be slightly further south than it was

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The Met Office forecast for Tuesday shows how useless auto generated apps can be, the 10-20% risk of rain between 1300-1400 contradicts the yellow warning
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Posted by Simon Cardy: “The large mature Cumulonimbus clouds over SE England (outlined purple on the map) are producing frequent lightning, very loud thunder and heavy rain. (credit: EUMETSAT).”

 

 

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Birth and death of a thunderstorm: May 28th 2018

After the previous two days’ thunderstorm events it would be easy for this one to get lost in the ether. However, being super local and how quickly it developed and then died was enough to pique my interest.

After a very warm and humid afternoon where the temperature peaked at 26.2C clouds began gathering to the east with the first rumbles of thunder at 6.45pm. The huge cumulonimbus could be seen from Southend.

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And Simon Cardy took an excellent shot from the other end of the Thames.

cardy1925

 

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By 8.17pm the storm that had moved west had decayed markedly.

sunset

The 24hr rain totals at 09 on May 29th show how local the storm was. St James’s Park, 9 miles to the south-east, recorded half Wanstead’s total.

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Timeline (BST)
1840 first peals of thunder heard
1847 first drops of rain
1856 downpour
1857 cloudburst
1901 16mm/hr 1.7mm
1903 very heavy
1909 burst of >5mm hail recorded. Rain rate 60.4mm/hr
1929 rain ceased (10.4mm in total)

nm9FIt

 

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Thunderstorms 26th-27th May 2018

Last night’s intense thunderstorm was probably most notable for its high-level sheet lightning than rainfall, thunder or fork lightning.

At my own station I recorded 4.8mm of rain which at its heaviest fell at a rate of 24.1mm/hr at 0046. To put that into perspective that’s just under a quarter of the rainfall rate during the thunderstorm at the beginning of last June. Rainfall in nearby Woodford Wells fell at a rate of 35.6mm/hr at 0040.

The rainfall was much heavier to the west of London. Screen Shot 2018-05-27 at 13.06.37

Also of note was how warm the night was. A low of 15.3C made it the 8th equal warmest May night since 1959.

There’s probably going to be a few more storms this bank holiday weekend though it remains to be seen whether this is going to be a classic summer for storms.

At it’s peak at 2305 there were 16800 strikes, according to Blitzortung.

Lightning from the storm in the early hours of the 27th caused a fire at a house in Romford.

There is an account of the family’s ordeal here.

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Here’s a few traces from the station.

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Around the capital and the south east

Elsewhere in London there was some excellent footage posted on social media.

Screen Shot 2018-05-27 at 13.03.15

 

The 27th was fairly quiet but with abundant sunshine and little wind it wasn’t long before more storms, this time homegrown, developed over the Midlands and the south. Severe flash flooding was reported in the Selly Oak area of Birmingham after a month’s worth of rain fell.

And as dusk approached a huge storm toward to the north-west of London and Chilterns. With little wind the storm stayed more or less in situ, expending all its energy with the most amazing lightshow – lightning within cloud that became more and more vivid as darkness approached.

Because these storms can reach heights of 29,000ft – roughly the height of Everest – they can be seen from over 40 miles away.

I had a go myself.

Screen Shot 2018-05-28 at 10.34.52

Not bad but the best footage I’ve seen was captured by Simon Cardy from east London and can be seen here.

 

 

I also took this video.

In the tracks of Luke Howard

The tow paths along the river Lea have provided generations of Londoners a place to escape – the route coming into its own following the legacy of London 2012 and the creation of the Queen Elizabeth Olympic Park.

bryant
The river Lea near the Bow flyover is roughly where Luke Howard’s chemical factory was situated

It also provided a means for Luke Howard’s commute to work when he moved his family from Plaistow to Tottenham in 1812.

Seven years earlier Howard set up his pharmaceutical laboratory on the banks of the Lea in the area where Bow flyover now stands. From this vantage point, as the factory produced chemicals including quinine, Howard kept a meticulous record of the atmosphere later publishing results in The Climate of London, among the first texts to discuss urban meteorology.

Development in the region was in its infancy and it would be years before the river banks became covered by factories and warehouses, these now fast making way for luxury flats and restaurants.

canal1`
The river is lined with canal boats, breweries, old factories, residential development and street art

I’ve often wondered what his journey to and from the factory was like so on Tuesday, tempted out by cloudless skies and a warm 23C I grabbed my bike and headed to the Olympic Park. Despite numerous visits I still got lost in the myriad paths in the park, turning into dead ends and finding myself on the ‘wrong side’ of canals.

Anyone familiar with Bow Flyover will know it’s not the most inspiring place; it probably represents the low point of the way north.

It was at this point in 1809 that Howard noted that the river had swelled to a width beyond a mile wide. Five years later Howard also noted how the Lea had become choked with ice following a bitterly cold winter, the year the last Thames’ Frost Fair was held.

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Anchor and Hope: a good spot to stop for a pint

As you ride north the familiar sites of the Olympic Park hove into view on the right while, if you look left, beyond the cacophony of the A12, the old Bryant & May match factory can be seen. Opened in 1861 the factory, which was one of the first east London renewal projects to feature luxury flats, is yet another landmark that simply wasn’t there in Howard’s time.

Just after Old Ford locks is a canal that turns left. This ‘cut’, called the Hertford union canal or Duckett’s canal, was in the process of being dug when in July 1829 lightning during a thunderstorm killed three workers. Howard, in one of many weather-based accounts in the The Climate of London, takes up the story:

A tremendous storm of thunder and lightning broke upon the metropolis about 1 o’clock on Saturday morning. The sky had been lighted up the whole evening by vivid electrical flashes and so late as half past twelve the stars were visible when a dark cloud suddenly arose and in a few minutes one of toe heaviest showers of rain and hail ever witnessed fell in torrents from its bosom.

Peals of thunder soon followed and continued rolling with scarcely any intermission for upwards of two hours accompanied with awful bursts of lightning; the residents of Bow, Stratford and Bromley were thrown into the greatest consternation by the violence of the storm, one poor fellow lost his life and two others have been so severely injured that but faint hopes are entertained of their recovery.

The three sufferers Sullivan, Salter and Fitzpatrick were engaged in excavating a canal, at present constructing by Sir George Duckett at Old Ford, and were at half past two o’clock diligently employed in their work when the storm commenced. Sullivan was at once struck lifeless and Fitzpatrick and Salter were so seriously injured as to make it necessary to procure immediate medical attendance.

Fitzpatrick was removed to his lodgings at Bow where he was attended by Dr Fairhead who on examining his person found that his left side had been most seriously injured and that there was reason to believe his intestines had suffered severely from the shock. The damage which Salter sustained has not been of so serious a nature.

Deaths caused by lightning were a much more common occurrence in the 19th century, mostly because so many people worked outside and the dangers of this natural phenomenon were not well document. The thunderstorm in July 1829 was particularly severe, as Howard continues:

During the continuance of the lightning on Friday evening a man who was employed in pumping in Bethnal Green fields which the late heavy rains have flooded was struck by a sudden flash which caused his instantaneous death.

The clothes exhibited a singular appearance being literally torn to atoms and every part of the metal in his buttons had the appearance of having been fused. The body itself showed no traces of the electric fluid with the exception of a slight mark on the forehead.

As you cycle on the factories / flats gradually thin out until you reach Lea Bridge Road when Leyton and Walthamstow Marshes become visible on the right. The big skies probably the same as they were during the 19th century. On reaching Tottenham Hale it is time to leave the river and turn left toward the town centre.

bruce
7 Bruce Grove, Tottenham.

A total of 6 miles later brings you to Howard’s family home, 7 Bruce Grove. It still stands but, despite having a blue plaque, is in a terrible state of repair – internal walls have collapsed and the roof is clearly porous. The owners have a plan to turn the building into flats but nothing has happened in years. A petition to save the building was set up a while ago but this, too, seems to have had little impact.

Howard and his family divided their time between here and Ackworth, Yorkshire. I’ve known about 7 Bruce Grove for years but I didn’t realise just how long the garden was, stretching back hundreds of feet.. It was here that Howard also kept a weather station and was the venue for his account of the partial solar eclipse in 1820.

monkey
The monkey puzzle tree

There is precious little left of the original garden, it being overgrown with bramble, nettles and alder. I did notice a tall money puzzle tree which I wonder once had pride of place in one of the borders.

Because of the dense undergrowth and it being behind a large wall there is precious little you can see but I wonder if there is any evidence of Howard’s meteorological enclosure somewhere in the garden?

It would be a fitting tribute Luke Howard if any future development would allow the provision of a weather station somewhere on the property.

rear
The rear of 7 Bruce Grove, Tottenham

 

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Walthamstow Marshes were flooded to a depth so great that many trees briefly disappeared

Thunderstorm: June 2, 2017

It’s not often you experience what it’s like to be right under a cloudburst but June 2, 2017, provided a perfect example.

Some 31.2mm of rain fell in little over an hour accompanied by frequent thunder and lightning. Some flash flooding was reported and there was an 8C fall in temperature in 2 hours. The max rainfall rate was 108.4mm/hr at 3.49pm.

The rain started at 3.14pmScreen Shot 2017-06-02 at 22.52.40.png

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Convergence https://twitter.com/wanstead_meteo/status/870659046038286337
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Streams appear at Heronry pond in Wanstead Park https://twitter.com/wanstead_meteo/status/870660267818070016
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Charts for the storm. https://twitter.com/wanstead_meteo/status/870683164049424384

 

Elsewhere in London there were reports of ‘golf ball sized’ hail in Orpington. Here is a link to the pictures posted on ukweatherworld.co.uk https://1drv.ms/w/s!Au79-nZSg0ihlSXF5dTb08AQB74b

Tudor Hughes, of Warlingham, NE Surrey, said: “Heavy thunderstorm 1525Z..  Torrential rain and a short spell of large hail near the end. The stones were all spherical with a maximum diameter of 12 mm.  Temp fell “vertically” from 22° to 17°.  Just measured the rainfall – 12.7 mm, the bulk of which fell in about 7 mins.  Rain now (1555 Z) ceased but plenty of Cb still around.”

Smartie, a contributor to the Google group Weather and Climate, explained the science behind the storm.

“The cold front was still to the west, these showers were in a prefrontal trough. South-east London was in the inflow region of the convergence zone and strong initial updraughts and unimpeded ingestion of air from the SE likely accounts for the hail. Storms north and north-east of London likely benefited from urban heat.”

Screen Shot 2017-06-02 at 22.42.07
The showers were in a prefrontal trough. Here is the 15 UTC WRF_LAPS objective 10m wind analysis. Red shades are convergence, blue-green divergence. SE London was in the inflow region of the convergence zone and strong initial updraughts and unimpeded ingestion of air from the SE likely accounts for the hail. Storms north and north-east of London likely benefited from urban heat. Chart courtesy of David Smart (UCL)
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This chart is a SharpPy analysis of the GFS analysis 12 UTC for the Heathrow grid point. Courtesy of Smartie
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The synoptic chart for 12Z shows the slack flow over London, the perfect set up for slow moving thunderstorms.

 

Christmas 1810: stormy then very cold

Earthquakes in Italy and early season snow cover in Siberia have been well documented in 2016.

They were also mentioned by Luke Howard in his publication The Climate of London in 1810.

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He also mentions winter thunderstorms over the Yuletide period, from Christmas Eve to Boxing Day – the amount of rain overflowing the Thames.

24th: Very windy night with heavy rain. 25th: Wind high all day with rain frequent lightning in the evening from SE. 26th: Wind very boisterous early in the morning day fine the rain of the last three or four days being impeded in its passage to the Thames by the spring tides overflowed the banks and filled the marshes.

Within two days of this wild and wet spell, complete with strong north-westerlies, the wind swung north and then north-easterly to usher in 1811 with a 12-day cold spell.

screen-shot-2016-12-17-at-20-55-36

The conditions of the cold spell were not severe, the coldest night was -8C, it was a pretty standard cold spell for the time and one that the south-east used to experience with fair regularity in the early to mid 1980s.

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Models currently show a (fairly) narrow chance of a stormy Christmas period. It would be interesting if it were followed with a cold spell in January – just like the ones we used to get in 1980s.

* The Booty website also contains the following on that notable month…
What is thought to be Britain’s strongest tornado occurred in December 1810. A category of “T8” (on a ten-point scale) occurred on the 14th at Old Portsmouth. The TORRO website says it:  “tracked from Old Portsmouth to Southsea Common causing immense damage – although no deaths, it is believed. Some houses completely levelled and many others were so badly damaged that they had to be demolished; chimneys were blown down and the lead on a bank roof was ‘rolled up like a piece of canvas and blown from its situation’.”

Summer 2016 review

Summer 2016 turned out to be a very decent season overall, the mean temperature of 18.7C (1.1C above average) made it the sixth warmest summer since 1797.summertop20

While it wasn’t quite up there with the hot summers of 1976 and 2003 it still produced some notable records. The stormy beginning to June effectively ended with the Brexit vote, a period of 24 hours that coincided with the highest daily rainfall this area has seen since at least 1959.

The multi-cell thunderstorm in the early hours of June 23rd produced 60.8mm of rainfall, nearly half of the month’s total which became the third wettest June in a record going back to 1797. The high rainfall was in complete contrast to July and August and helped skew the overall figure: 168.6mm is 114 per cent over average summer rainfall.

sunWith so much rainfall overall sunshine was affected with only 451 hours recorded, just 80 per cent of what can be expected in an average summer.

July produced another record, this time the highest overnight minimum recorded since 1959. The minimum of 21.1C was recorded during the early hours of the 20th – coming hours after the hottest day of the year: 33.5C – the 14th hottest day on record.

The warm and very dry theme continued into the final month of summer with the warmest August for 12 years, the 10th warmest and 12th driest since 1797.

My summer forecast, when the monthly probabilities are considered, was broadly correct though I didn’t estimate correctly just how warm it would be.

Mean forecast: 16.7C (outcome 18.7C)
Rainfall forecast: 166mm (outcome 168.6mm)
Sunshine forecast: 546hrs (451.4hrs)

summer2016mean

summer 2016 rain

summer 2016 sun

 

 

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

 

 

August 2014 – cool, wet and dull

Anyone hoping for a continuation of June and July’s hot weather would have been left sorely disappointed by last month which was characterised by frequent rain and the coldest August night for over 20 years.

A stunning example of sunlight illuminating the underside of cloud at sunset was seen mid-month
A stunning example of sunlight illuminating the underside of cloud at sunset was seen mid-month

August 2014 was the first month this year to be cooler than average; the mean temperature of 17.2C was 1C below average, making it the 89th warmest August since 1797: 1.6C cooler than last August, the coolest for 7 years.

The month was marked with thunderstorms and heavy downpours, contributing to what was a much wetter than average month – some 76mm fell which is 152% of the monthly average and the wettest for 4 years.

The hottest day occurred on the 7th with 27.3C recorded – nothing special for August and a date that heralded the end of the hot spell during June and July.

A couple of nights were notably cool for August: 5C was recorded during the early hours of the 23rd – the coldest August night since 1993.

Sunshine was below average with 161 hours recorded – that’s 83 per cent of mean. The sunniest day was on the 3rd when 12 hours of sunshine were recorded. Throughout the month there were just 2 days with 10 hours or more of sunshine. There were 4 days with thunder recorded – the average for August is 3.

To view full stats follow this link:http://1drv.ms/1kiTuzv

Looking further afield there were many thunderstorms around the UK though many places missed out on the big downpours. It was yet another month where rainfall totals could vary greatly in the space of just a few miles.

On the 9th a station in Woodford Green recorded 24.4mm, double what fell in Wanstead. The legacy of TS Bertha coincided with the end of our extended hot spell – an excellent analysis of this storm can be found here.

There were some spectacular cloud formations not far from here. A particularly good one was seen in Witham. 

Squally storm line approaching Witham, panoramic shot!

Prolonged heavy rain on the 11th caused extensive flooding in Scotland.

On the 14th ‘Biblical’ flooding affected Lewisham in south east London.

On 25th a perfect curl could be seen on a depression centred off the west coast of Irleland. The rain associated with this low pressure brought the month's highest daily rainfall total: 23.4mm (the system bringing 27.5mm) - a thoroughly miserable Bank Holiday Monday where it rained ALL day, from 6am until 9.30pm. It was yet another example of how much even frontal rainfall can vary over a small area.
On 25th a perfect curl could be seen on a depression centred off the west coast of Irleland. The rain associated with this low pressure brought the month’s highest daily rainfall total: 23.4mm (the system bringing 27.5mm) – a thoroughly miserable Bank Holiday Monday where it rained ALL day, from 6am until 9.30pm. It was yet another example of how much even frontal rainfall can vary over a small area.

On 25th a perfect curl could be seen on a depression centred off the west coast of Irleland. The rain associated with this low pressure brought the month’s highest daily rainfall total: 23.4mm (the system bringing 27.5mm) – a thoroughly miserable Bank Holiday Monday where it rained ALL day, from 6am until 9.30pm. It was yet another example of how much even frontal rainfall can vary over a small area with St James Park recording 38.2mm. The top 30 totals for that day can be seen here.

sunset overlooking Wanstead Flats 2nd August
sunset overlooking Wanstead Flats 2nd August

Looking even further afield four people were killed in a flash flood at an Italian festival early on in the month.

 

Overnight storms of July 18th 2014

I’ve decided to cobble together a few lines on last night’s notable thunderstorms which reminded me so much of the stormy nights on the 1980s.

The radar at 3am, produced by the excellent Hone and Dry, revealed that the storm's rainfall was quite widespread. The white areas show the most intense rainfall
The radar at 3am, produced by the excellent Home and Dry, revealed that the storm’s rainfall was quite widespread. The white areas show the most intense rainfall

After writing off the risk of storms for our area last night I was awoken at 3am by loud, rumbling thunder – the kind that seems to resonate all around you. A quick look on the radar revealed quite a widespread thunderstorm, quite different from the smaller, more intense one that woke up most of Wanstead on July 23rd last year.

On viewing the live lightning map at 3.10am it became clear that this was no flash in the pan. Further rumbles and strikes had me leaping out of bed to monitor the station. EssexWeather reported 1809 lightning strikes in two hours for our region.

And on viewing the pressure graph the first storm saw a 6mb fall in pressure in a matter of minutes.

A second storm around 5.30am was less severe though still notable. The 9.4mm that the weather station recorded fell at a rate of 45mm/hr at 3am and 40mm/hr at 5.15am. Though the AWS is often out in heavy rainfall situations on this occasion it was more or less spot on – my 10am reading of my traditional 5″ raingauge revealed the official total to be 9.3mm. The rain took the July  total to 108% of the 1981-2010 mean.

And a squall that blew through just before 4am is well portrayed on this wind graph.

So, all in all, a really lively sticky night where the temperature didn’t fall below 18.2C. I didn’t manage to get any of  my own pictures but this one by @justinstokes on Twitter caught my eye.

According to the CAPE / lifted index further storms seem likely tonight. Indeed the situation across the Channel could be dire. It is probable a few will trundle their way across the sea to give us another sleepless night…
lightning canary wharf

This wind graph shows a gust of 22.8mph at 0336z in my sheltered garden
This wind graph shows a gust of 22.8mph at 0336z in my sheltered garden
Radar at 0519 shows another white blob (very heavy rain) about to cross Wanstead
Radar at 0519 shows another white blob (very heavy rain) about to cross Wanstead

 

This pressure trace shows the fall in pressure of the two thunderstorms that crossed our region
This pressure trace shows the fall in pressure of the two thunderstorms that crossed our region
Live lightning map from http://www.lightningmaps.org/realtime at 3.10am
Live lightning map from http://www.lightningmaps.org/realtime at 3.10am