All posts by wansteadmeteo

A blog that tries to make sense of how the UK's national climate translates into local weather for Wanstead and the surrounding regions of east London and west Essex. Check out my twitter feed @wanstead_meteo for local weather forecasts, stats, records and phenomena for the east London areas of Wanstead, Aldersbrook, Leytonstone and Stratford. And anything else weather

A dry or wet St Swithun’s?

St Swithun's reputation as a weather saint is said to have arisen from the translation of his body from a lowly grave to its golden shrine within Winchester cathedral, having been delayed by incessant rain for 40 days
St Swithun’s reputation as a weather saint is said to have arisen from the translation of his body from a lowly grave to its golden shrine within Winchester cathedral, having been delayed by incessant rain for 40 days

Legend has it that the weather on Monday will be the same for the next 40 days.

St Swithun’s day, if thou dost rain,
For forty days it will remain;
St Swithun’s day, if thou be fair,
For forty days ’twill rain na mair.

St Swithun’s Day is probably among the most well known of weather folklore – but, taken at face value, it is probably the most unreliable.

Since 1961 Wanstead has enjoyed 30 dry St Swithun’s Days (57%). From these the longest dry spell that followed was just 18 days, in 2000. On average, if St Swithun’s is dry, the weather stays fair for five days, with rain arriving on the 20th.

Another interesting observation is that the 40-day period that followed a dry St Swithun’s is on average 13% WETTER than if it rained on July 15th.

So what does this mean for the rest of July and the summer? Looking back at other years that have seen a mostly dry and warm pattern in the run up to St Swithun’s Day we should see a continuation of the mostly dry, warm and sunny conditions, perhaps with frequent thundery breakdowns, the first arriving on Thursday into Friday.

Putting superstition and singularities aside current weather models back this up.

Featured Image -- 1745St Swithun was born around 800AD and died on July 2, 862, at Winchester, Hampshire. According to historians he was fond of building churches in places where there were none. St Swithun, who was bishop of Winchester, was buried in the churchyard of the Old Minster at Winchester, where passers by might tread on his grave and where the rain from the eaves might fall on it.

His reputation as a weather saint is said to have arisen from the translation of his body from this lowly grave to its golden shrine within the cathedral, having been delayed by incessant rain for 40 days.

The basis of the St Swithun’s saying follows the fact that by July 15th summer weather patterns are already well established and tend to persist through the coming weeks.

In meterological terms the position of the frontal zone around the end of June to early July, indicated by the position of the jet stream, determines the general weather patterns (hot, cold, dry, wet) for the rest of the summer. Like a little stream in its bed, the frontal zone tends to ‘dig in’ shortly after the summer solstice.

As the path of our weather systems is controlled by the jet stream, a more southerly location of the frontal zone – as happened last year – is likely to bring unsettled, wet and cool weather. On the other hand, a frontal zone shifted further to the north – as is happening this year – will help the Azores high to build over western Europe, thus bringing dry and pleasant weather to the UK.

Other western European countries also have similar St Swithun’s day sayings – that follow the principle rule. In France they say ‘Quand il pleut a la Saint Gervais Il pleut quarante jours apres’ – If it rains on St. Gervais’ day (July 19th), it will rain for fourty days afterward.
In Germany the Siebenschlaefer or seven sleepers day (July 7th, after the Gregorian calendar) refers to the weather patterns of the following seven weeks.

June 2014: warm and dry

June 2014 continued this year’s theme of being milder than normal; the mean temperature of 17.1C was 1C above average, making it the 22nd warmest June since 1797.

little fluffy clouds
June was marked by some spectacular cloudscapes and sunsets. This was the view across Wanstead Flats from Centre Road looking toward Ilford on the 21st

June, like  March and April, was dryer than average with just 15.2mm of rain, that’s just under 30 per cent of average.

The driest June since 2000 started off unsettled with frequent rain – 6mm falling on the 3rd. The following day was cool with the temperature reaching just 16.2C.

Though there were nine days when over 10 hours of sunshine was recorded the magic 80F was surpassed just once: on the 9th when 27.5C was reached under 6 hours of sunshine. This sunniest day was the 10th when 14 hours of sunshine nudged the thermometer to 24.5C. Overall there were 214.1 hours of sunshine – that’s 120% of average, the sunniest since 2011.

On many days during June, including the 30th shown here, the sky turned dark but just spits and spots of rain were often produced
On many days during June, including the 30th shown here, the sky turned dark but just spits and spots of rain were often produced

Despite plenty of potential no incidents of thunder were recorded – the much-hyped weekend of the 7th / 8th saw less than 2mm of rain – all of the action staying well to our east in the France, Germany and the Low Countries. Further thundery potential on the 13th failed to produce anything in this area though a disturbance over Berkshire saw thunderstorms develop in the Oxford, Reading, Basingstoke and Wokingham region, with up to 38mm of rain falling over a wide area.

It is a typical feature of summer that rainfall can vary a great deal across a small area. The nearest official station to Wanstead, St James’s Park 8.4 miles to our south-west, recorded 33.8mm – more than double what fell here.

Some nights were chilly when the sky cleared but there was no air frost or ground frost.

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

Yet another occasion of impressive cloud formation during June included this example of late evening cirrus. The formation, seen at ground level, seemed similar to a display of the Aurora
Yet another occasion of impressive cloud formation during June included this example of late evening cirrus. The formation, seen at ground level, seemed similar to a display of the Aurora
Circumhorizontal arc over Aldersbrook
Circumhorizontal arc over Aldersbrook

June deluge that created Redbridge-on-Sea

It was the summer when the ‘sea’ came to Redbridge.  A record-breaking 59-hour deluge in the middle of June 1903 left vast swaths of the borough inundated. But this was no thundery downpour. All across London and the South East record rainfall rates and totals were set, many of which still stand well over a century later.

The writer of this postcard wrote the following: "Just sending you a few postcards to let you see what a plight we have been in Ilford. This view is the River Roding from the bridge. This was a large green field now it is like a large river but glad to say it has subsided a little of course. You will have read it in the papers I have sent you."
The author of this postcard wrote the following:
“Just sending you a few postcards to let you see what a plight we have been in Ilford. This view is the River Roding from the bridge. This was a large green field now it is like a large river but glad to say it has subsided a little of course. You will have read it in the papers I have sent you.”
This terrace of houses in Wanstead Park Road, which backs on to the River Roding, were also flooded out. The postcard was written on July 1st, 1903
Images of the flooding were captured by Watson Hornby, an amateur photographer and artist, who traded at 7 Cranbrook Road, Ilford. This terrace of houses in Wanstead Park Road, which backs on to the River Roding, were also flooded out. The postcard was written on July 1st, 1903

According to one local historian the fields between Wanstead Park and Ilford – as far as Uphall Road – were like an open sea and the railway track at Seven Kings resembled a shallow river.

After a dry start to the month June quickly went downhill with notable falls of rain during the second week. The main deluge arrived around noon on Saturday, June 13, and lasted until near midnight on the 15th.

The rain was caused by a depression that moved slowly across southern England, becoming stationary over the English Channel close to the Isle of Wight for 24 hours before moving north-east. It introduced a very cool NE’ly airflow – the temperature on the 14th and 15th failed to climb above 11C and on the 19th a high of just 9.2C was recorded as yet more rain fell. 

Across the London area there were five days within the period 10th to 19th June when over 25mm of rain was measured in many places. The deluge added to what became the wettest summer month on record. At the Royal Observatory, Greenwich, just over 154mm fell, three times the amount of what normally falls in June in this area. Further west, Kew Observatory recorded 184mm.

The June 1903 flood at Empress Avenue at the junction of Wanstead Park Road
The June 1903 flood at Empress Avenue at the junction of Wanstead Park Road

The 1903 rains produced an unprecedented summer flood on the Thames. At Teddington 7335 million gallons (33,374 million litres) of water flowed over the weir on June 21st. Elsewhere the Lea Valley was one vast lake, especially around Enfield, with the Royal Gunpowder Factory inundated.

The Friday, June 19th edition of the Essex County Chronicle abounds with other tales of woe from the floods…

Barking and District: In the large area of low-lying ground between Lea Bridge, Ilford, Barking, and East Ham, houses stood in a great inland sea, which was washing over the garden fences and lapping at the lower windows. Upstairs the occupants could be seen moving about or gazing hopelessly out at the dreary waste of black waters. Boats from Barking Creek were rowing about with supplies of milk and bread, and those who wished were taken away. All along the Barking Road from East Ham scenes almost identical were witnessed, but, happily with the end of the rain, the water did not retain its level long. Past Barking and on to Rainham the roads on Tuesday were quite impassable, much of the heavy traffic which goes through Rainham towards Barking having to turn back.

The floodwaters between Wanstead Park and Ilford were described as a vast inland sea

Woodford and Wanstead: The inhabitants of Claybury Asylum and Woodford Bridge were cut off by 3ft of water from Woodford. The whole of the Roding Valley was in a deplorable state; sheds, trees and stock that was once alive floating in all directions. Wanstead was divided from Ilford by a great lake, but happily the total of loss in property was here very small.

Lea Bridge: The Leyton marshes were covered by one great sheet of water, Lea Bridge Road itself being quite 2ft under. Boats were to be seen plying among the tramcars.

Epping: The valleys were well-nigh impassable, especially at Thornwood and parts of Theydon Bois.

Romford: The floods reached to Romford High Street, and made the thoroughfare impassable for pedestrians. The crisis caused a heated exchange among members at a meeting of the Urban Council on Monday evening where it was agreed to allow the free use of the town fire engine for pumping water from ratepayers’ premises, provided that those who required its services paid for the labour. Cllr J. Bassett thought the residents should make their own arrangements for getting rid of the water. Cllr J.R Holliday replied: “You don’t live near the river. I should like to stick you in the middle of it. I think it is the duty of the council to protect property.”

Laindon: Here the height of the deluge was experienced between seven and eight o’clock on Sunday evening. The rain descended in apparent ropes of water, causing consternation, flooding houses, choking drains and water-troughing, cutting deep channels in roads, washing up plants and new potatoes. On Monday the water was between 3 and 4ft feet deep at Noak Hill and other bridges.

Woodford: An exciting scene took place at Woodford Bridge, where a steam circus, with its owners, was in the most precarious position. Men and women were submerged up to their armpits while extricating the caravans.

rainfall tableAway from the South East the weather was much dryer. Felixstowe and Yarmouth newspapers reported that Sunday had seen “delightfully sunny weather, with cool north-easterly breezes”. Lincoln, meanwhile, recorded less than an inch of rain for the whole month!

Could these rains happen again? Meteorologically, given the same synoptic set-up, it is possible. In terms of the June monthly total of rain we came close in 1997 when 133mm fell – though this was much more evenly spread throughout the month. And thanks to massive investment in local river systems since the 1950s the flooding nightmares brought by the Lea and Roding rivers should stay firmly in the past.

 

*You can see the full stats from Greenwich for June 1903 by clicking this link.

 

500hPa evolution from June 9 - June 20
500hPa evolution from June 9 – June 20

Captivating clouds and superlative skies

Considering we had no thunder to speak of and the threatened thunderstorms failed to materialise in this region we still saw some amazing skies at the weekend. Testament to the fact that the weather is never boring…

I took this yesterday evening. Windless, still and humid at ground level it was fascinating to look skyward and see the multi-level cloud continue to build into strange shapes, illuminated from below by the setting sun. A wonderful weekend for cloudspotting.
I took this yesterday evening. Windless, still and humid at ground level it was fascinating to look skyward and see the multi-level cloud continue to build into strange shapes, illuminated from below by the setting sun. A wonderful weekend for cloudspotting.
Wanstead Flats sunset
Wanstead Flats looking west
little fluffy clouds
Little Fluffy Clouds over Wanstead Flats. The contrast of the deep blue, white clouds and green grass never fails to disappoint as we approach the Solstice
shard
A walk along the foreshore on the north bank of the Thames revealed this vista. The Shard looks very other worldly and looks like I’ve Photoshopped it in. Love it or hate it, the thing is there for good now…

swirl

Looking south from Borough
Looking south from Borough

photo (2)

Flashback to a period of flash floods

storm2The Met Office, earlier this week, warned us that extreme summer rainfall may become more frequent in the UK because of climate change. The research, produced in collaboration with Newcastle University, says that while summers are expected to become drier overall  intense rainfall producing serious flash flooding could become several times more frequent.

I hadn’t thought much about the story until, as part of my attempt to find out what this summer is going to turn out like, I discovered some fascinating details of several events during the summers of 1811 and 1828. Many have remarkably similar characteristics to the Boscastle flood in 2004 – the kind of episode the Met Office tells us could become far more common by 2100.

The entries for 1811 in Luke Howard’s book The Climate of London once again shows that extreme weather is nothing new and serious flash flooding was actually more common all those years ago.

May 20 1811 A severe thunder storm came on at Ingatestone, Essex, accompanied with a deluge of rain. In ten minutes the water ran about three feet deep in the streets. The same night at Potter street on the road to Newmarket hailstones nearly as large as pigeons eggs fell accompanied with the most terrific thunder and lightning.

May 27, 1811 Hereford: We were visited by a dreadful storm of thunder and lightning accompanied by torrents of rain very destructive eastward of this city. It commenced about three o’clock in the afternoon and continued with little intermission till past eight. This storm and the consequent inundation of several thousand acres of land destroyed a number of lives and much property.

June 8, 1811 A severe storm of rain hail and lightning took place in Birmingham and the neighbourhood. The hail or rather pieces of ice which fell are described as of prodigious size and considerable damage has been done to the windows.  Worcester this day another most tremendous storm of thunder lightning and rain took place about 11am equal to that of the 27th except the hail.

A storm was also experienced June 28 at Bury and its neighbourhood. The lower part of the houses were filled with water which lay in the street 5 feet deep. The hail stones 5 8ths of an inch in diameter broke near five thousand panes of glass. About twenty six head of cattle were killed last week by the lightning at Bisby and Walsham in Norfolk.

July 2, 1811 In the neighbourhood of Wonersh near Guildford after one of the most sudden strokes of thunder a deluge of rain took place so instantaneously as to carry away or destroy every thing which impeded its progress. The damage is estimated at not less than 1,500.

July 21, 1811 A heavy fall of rain did much damage at Stamford. In the meadows about Barrowden, Wakerly, Harringworth, Thorpe, Caldecot and Bringhurst immense quantities of hay were carried away. Several thousand loads it is supposed have been destroyed in addition to which the injury sustained by the land has been very great. The water rose thirteen feet in less than four hours in Wood Newton parish.

View from Greenwich Observatory toward the Royal Naval College
View from Greenwich Observatory toward the Royal Naval College

In 1828, a spring that was also similar in terms of temperature and rainfall to this year, more entries in Climate describe flash flooding events.

July 8, 1828 Extensive rains on Tuesday afternoon the 8th instant about four o’clock a storm of wind rain and hail accompanied with thunder and lightning broke over the town and neighbourhood of Taunton with a degree of violence never before remembered by the oldest inhabitant. The thunder in heavy peals was heard simultaneously from the east and west and the wind at one period of the storm blew a perfect hurricane. At Kingston the banks were thrown down for several miles and three rams the property of Mr Welch valued at thirty pounds were killed by the lightning. The corn is sadly levelled by the storm. The hailstones were of uncommon thickness and in their descent destroyed much glass in the windows of private dwellings and outhouses. Various statements of mischief have reached us from our correspondents for many miles round all representing the storm to have been of unqualified violence.  Taunton Courier

The inundations occasioned by the constant heavy rains in Flintshire and Denbighshire have proved most injurious and in some instances destructive to the iron works in those counties. The Coed Talon works belonging to the Welsh Iron Company have sustained very considerable injury, the bridges, dams and culverts belonging to those works were all carried away by the tremendous torrents and bursting of the springs. On Thursday night week the waters in the immediate vicinity of the works rose to the extraordinary height of 22ft above their ordinary level and in a few hours extinguished the furnaces such was the impetuosity of the flood and the influence of opposing elements of fire and water that the most serious apprehensions were entertained that the furnaces would have been blown into the air.

Wanstead Flats by Scott Whitehead
The Met Office says summer deluges and intense rainfall will become more common

Happily the buildings sustained the shock and no lives have been lost. It is stated by the oldest inhabitants in the neighbourhood that such awful effects from impetuous torrents were never before witnessed by them. Throughout a great part of Oxfordshire and Worcestershire the wheat and barley have suffered considerably by the late heavy rains Friday afternoon, a solitary dark cloud passed over the north end of Winchester towards the valley of Itchen Abbas the sun shining from the opposite part of the horizon. The spot whereon the cloud appeared to rest seemed to be enveloped in total darkness whence shot a stream of electric fluid accompanied by a short but tremendous crash of thunder and hailstones of considerable magnitude. So violent was its force that it killed two fine horses belonging to Mr Twitchen of Itchen Abbas and struck the carter to the ground where he lay in a state of insensibility for some time, his frock was singed by the lightning. About the same time a cottage occupied by the shepherd of Mr Twitchen s brother at Mitcheldever experienced its violence by being greatly shattered and the shepherd’s wife struck instantly dead. During the same day three horses belonging to Mr Budd of Hatch Warren Farm, near Basingstoke, were struck dead by the electric fluid and a man who had charge of them was so dreadfully injured as to render recovery hopeless. Bath Chronicle

The list goes on… I’ve had a look at all summer rainfall since 1797 to see if 1811 and 1828 were particularly wet years but the records I have, taken by Luke Howard at Stratford, are nothing out of the ordinary.

The summer of 1811 in London saw a mean temperature of 16.1C (1.5C cooler than the current 1981-2010 average) while rainfall was 211mm (just under 150% of the current average). The summer of 1828, however, was warm for the period – at 17.5C. Rainfall was high at 317mm (218% of today’s summer average). Of course totals in the areas affected in the articles would have been much higher.

So when the Met Office says climate change is going to bring more flash flooding in summer I wonder if it is the climate cycling back to a period where we’ve seen it all before.

This graph of summer statisitics shows a regular series of peaks and troughs for rainfall. The mean temperature is generally 1C warmer than it was 100 years ago
This graph of summer statisitics shows a regular series of peaks and troughs for rainfall. The mean temperature is generally 1C warmer than it was 100 years ago

*For  those interested below is a continuation of summer flooding events that plagued the country in 1811, 1828 and possibly many other events of records we have probably sadly lost.

 

Sussex The accounts from the western part of this county both on the coast and in the weald concur in stating that the effects of the thunder storm of the 3rd instant were most severely felt. So severe a storm has not been experienced since 1821. The storm on the evening of Thursday night was most violent in the neighbourhood of Chichester and lasted from eight in the evening till nearly four in the morning, the electric fluid entered a cottage at Birdham and shivered a bedstead rolling its occupier with the bed on the floor lut who escaped without injury. Brighton Herald

The almost constant rain which has been experienced in Penzance and its neighbourhood has been very detrimental to the hay harvest West Briton PL

July 10, 1828 We regret to state that the floods in this neighbourhood still continue and the waters indicate by their colour how great the mischief is amongst the hay. The Welland and the Nene are of the hue of strong tea proceeding from the essence of the hay which is entirely washed out of whatever was not stacked before the 10th instant. –  Stamford Mercury

Cambridge The late heavy rains in this part of the county have laid and much injured the corn crops and likewise considerably impeded the hay harvest Bury Herald

July 17, 1828 Sheffield In our last publication we alluded to the long continuance of hot weather which had been experienced in this neighbourhood. On Tuesday, however, a change took place and on Wednesday the rain fell more heavily and incessantly than it is remembered to have done at the same season for several summers past. Indeed not only were our two rivers remarkably high but the springs of many wells which had failed at the usual time experienced a temporary refluviation. Sheffield Iris, July 17

Malton, July 17 Every hour brings fresh accounts of the extensive losses sustained by the occupiers of land bordering on the Rye and Derwent. Hay has been floating in swarth and in cock of all sizes and the loss in various kinds of grain and potatoes is incalculable. Such a weight of rain and such a flood were never known at this season of the year. On Sunday morning last Sunderland was visited by a thunder storm. The lightning was remarkably vivid the peals of thunder were tremendous and the rain fell in torrents. The Wear was also much swollen. Great quantities of hay came down the river. From our correspondent at Durham dated Sunday afternoon: Since early on Saturday morning Durham and the neighbourhood have been visited with a succession of heavy rains insomuch that the river Wear is swollen to a dreadful height and has done and is still doing frightful damage to the adjacent fields which are overflown to the extent of many hundreds of acres many of which are meadow some just mown some in pike and some standing uncut – Tyne Mercury PL, July 17

Doncaster, July 19 I have within a few days been over a considerable tract of land in this and the adjoining county for the purpose of ascertaining the effects of the late floods on the crops. A great portion of the country through which the Derwent runs as well as the other rivers which empty themselves into the Humber has been overflowed to a very considerable depth and the consequence has been the complete destruction of the greater part of the grass which was cut and those crops which were not cut will not be worth the trouble. We regret to state that in this town and neighbourhood the weather has continued extremely unfavourable throughout the week. Scarcely a day has passed in which we have not been visited by heavy falls of rain accompanied in some instances with thunder and lightning. We have not heard of any further injury being done in the vicinity by floods but we fear that the wheat and other crops as well as fruit and vegetables will suffer greatly from the long continuance of wet weather. –  Manchester Mercury PL, July 20

Although within the last few days several thunder storms have fallen in this immediate neighbourhood we have not heard of any serious injury to life or property. On Wednesday week 9th at Great Houghton during a thunderstorm the lightning descended through the sky light which it destroyed in the roof of Mr Brook’s house and through the ceiling into an upper apartment and shook down the tester of the bed on which Mrs Brook was reposing without, however, inflicting any injury further than the alarm into which she would naturally be thrown. Its course was then along a passage in which there was a cupboard whose contents of glass and earthenware were partly demolished and the door of the cupboard dashed along the passage at the extremity of which was a young female who happily escaped unhurt. – Doncaster Gazette PL, July 21

Newark July 21, 1828 You cannot possibly have an idea of the effects of the late stormy weather and the consequent inundation of the large tract of country unless you were to see it. All the country from this place situated on the banks of the Trent down to the Humber has been completely overflown and has borne the appearance of one expansive sea.

Bedford July 22 In consequence of the dreadful and continued rains every thing in the neighbourhood of this town is in the most frightful state. The Ouse has overflowed its banks in every direction as well below as above the bridge and for miles nothing is to be seen but a weary waste of waters with islands of hay or haycocks. The early season for hay gathering in the northern counties was favourable in the extreme and a great quantity of hay out of the abundant crop was secured in capital condition. About the middle of the last week the barometer sunk rapidly and torrents of rain fell day after day till the rivers became swollen and on Sunday and Monday last vast tracts of land particularly in the southeast part of this county extending from Doncaster to Hull were inundated. Even in the neighbourhood of Wakefield the hay was seen floating in the fields and near Barnsley a great deal was either washed away or rendered useless except for litter. The corn crops have also been much beaten down by the heavy rains and potatoes in low situations have suffered from the floods. – Leeds Mercury

Whitby From the 8th to the 13th instant a succession of heavy rains has been experienced at Whitby and its neighbourhood which did considerable damage to the bridges on the Esk. On Sunday morning the platform of the elegant suspension bridge at Ruswarp belonging to James Wilson Esq MP was wrenched from its abutments and together with the cast iron pillars was thrown into the stream. The small stone bridge recently erected by Edmund Turton Esq on the new line of road was also carried away likewise a bridge at Cock mill and another in the neighbourhood of Egton. The neat bridge at East Row has been so far injured as to be passable only by foot passengers. Great quantities of timber, hay were washed away and the fields and gardens completely flooded. From all parts of the country accounts pour in of the disastrous effects produced by the late uncommonly heavy rains. From Ganstead and Withernwick in Holderness to beyond Driffield a distance of from twenty five to thirty miles the country presents an almost unbroken sheet of water. The quantity of hay corn and potatoes destroyed and likely to be so is beyond all calculation thousands of acres of the latter are literally rotting in the ground. From Doncaster down to Gainsborough and the low grounds at the junction of the Ouse and Trent the inundation is stated to have been still more destructive than in this immediate neighbourhood. – Hull Advertiser

The south western districts of Scotland appear to have been visited by the same excessive quantity of rain that has been experienced so generally over England. It would appear, too, that the crops there are in general good and that the wheat in particular promises to turn out better than in the south July 30.

 August 1828

Deal Aug 9 The wind has blown very hard the whole of this afternoon at intervals almost a hurricane. Wind WSW

Brixham (Torbay) Aug 9 At three o’clock this morning it came on to blow quite a hurricane from the SSW and continued unabated until four this afternoon since when it has been more moderate.

Falmouth Aug 9 It blew a heavy gale here last night and continued until noon this day from the SSE to WSW

Penzance Aug 9 The wind has blown a perfect hurricane from SW all this morning. Accounts of damage.

Noon. PL The storm still continues with unabated fury. Great numbers of trees have been blown up by the roots and many mows of corn in the fields are quite upset and the sheaves blowing about in all directions PL

The Thames was higher on Wednesday last than has been known at this season for twenty seven years. All the low land about Goring Pangbourn Mapledurham, Caversham, Sonning &c was under water. – Berkshire Chronicle

 

 

 

 

Summer forecast: barbecues and umbrellas

This has been fully updated to take into account May statistics

Wanstead Meteo

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…

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May 2014: mild but wet

May 2014 continued this year’s theme of being milder than normal; the mean temperature of 13.9C was 0.9C above average, making it the 28th warmest May since 1797.

May was wetter than average, ending the dry theme of March and April.  71mm of rain fell over the 31 days – that’s 139 per cent of average.

The month wasn’t a complete washout with some very warm days during the third week, topped off with long sunny spells. The warmest day was the 19th when 26.7C was reached – the first ^80F temperature of the year – with 9 hours of sunshine. This followed the sunniest day on 18th when 14 hours of sunshine nudged the thermometer to 25.2C.

Of note this month was the number of thunderstorms with four incidents of daily thunder – one more than what we’d expect during a month in high summer. The most notable day of thunder was on the 24th when the temperature dropped over 6C in an afternoon shower.

This screen grab shows the thunderstorm at 4pm on 24th that saw the temperature fall nearly 6C in a matter of minutes
This screen grab shows the thunderstorm at 4pm on 24th that saw the temperature fall nearly 6C in a matter of minutes

May saw just 157.3 hours of sun, 87 per cent of average, making it the dullest for 10 years

this image shows the storm squall on May 24th that brought a near-6C fall in temperature in minutes
this image shows the storm squall on May 24th that brought a near-6C fall in temperature in minutes

and the 22nd dullest since 1881. Indeed May was on sunnier than March by 4 hours.

Some nights were chilly when the sky cleared but there was no air frost and only two ground frosts, on the 2nd and 3rd.

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

Tragic London storm marked slide into WW1

Over the years significant weather events have, at least in my subconscience, at times signalled that something ‘big’ is about to happen – just one example being the Great Storm in October 1987 that was followed days later by the Black Monday stock market crash.

So an event that happened 100 years ago this month, to some, probably also brought a feeling of impending doom as the political situation in Europe became ever more fraught.

Account of the thunderstorm reported in The Times
Account of the thunderstorm reported in The Times

A series of severe thunderstorms that broke out just after midday over south-west London on June 14, 1914, left people dead and a trail of destruction across areas south of the Thames. Fierce lightning, torrential rain, severe flooding and hail ‘the size of walnuts’ accompanied the storms. Seven people were killed by lightning on Wandsworth Common and four others were injured. As with many thunderstorms the heaviest rain, 94mm in 3 hours at Richmond Park, was focused over a small area. South Kensington, just over 5 miles away, recorded just 6mm! I don’t have the figures for Wanstead but judging by the map published in the 1914 edition of British Rainfall it probable recorded even less than South Kensington.

Some reports by observers.

Dulwich: Violent hailstorms. Many hailstones were like acid tablets about one inch long, half an inch broad and over a quarter of an inch thick. A minute or two after these had fallen, a mist rose to a height of about 4ft above the ground.

Lewisham: A storm began at 12.24pm and came right overhead from the east with terrific flashes of lightning and loud thunder. At 12.31pm, rain fell with extraordinary fury; within 9 minutes 0.5 inches had fallen. The second storm came up just after 1pm, the lightning being even more severe. At 1.30pm, St Mark’s Church, and the Holy Cross were  struck. A tree in Hither Green cemetery over 30ft high was splintered and two houses were struck at Catford. Another thunderstorm came up at 2.25pm with torrents of rain and hail as large as haricot beans fell for 5 minutes.

Rainfall in the London area - June 14, 1914 - shown in the publication British Rainfall
Rainfall in the London area – June 14, 1914 – shown in the publication British Rainfall

Richmond Park: Very severe storm passed over the house; an oak fence was struck by lightning in two places. Rainfall measurements were as follows: 1.80 inches in 45 minutes, 2.70 inches in 90 minutes, 3.2 inches in 2 hours, 3.60 inches in 2.5 hours, 3.70 inches in 2.75 hours.

Wimbledon Downs: There was a curious scene close to Kingston station, where the water was about 4ft feet deep at five o’clock and motor cars and omnibuses had to make a wide detour. The storm was especially severe in Wimbledon district, where, owing to the bursting of an overtaxed sewer, the District Railway line was submerged. At Tooting Junction station was a foot deep on the platform.

Judging by the 1881-1910 average 1914 was a warm year: the mean temperature of 10.7C  was a full degree warmer than average. It was also 15 per cent wetter than average and the sun hours were nearly 108% of average. Of course by today’s standards (the 1981-2010 average) 1914 looks relatively cool as the average annual temperature has risen 1C in the past hundred years.

The weather on this day must have been synonimous with the deteriorating political situation in Europe: two weeks later Franz Ferdinand, Archduke of Austria, and his wife Sophie were assassinated in Sarajevo by a young Serbian nationalist Gavrilo Princip , the casus belli of the First World War.

What is fascinating is that a similar thunderstorm that left seven dead in Valentines Park, Ilford, 75 years ago this August, also happened about two weeks before Prime Minister Neville Chamberlain announced on September 3, 1939, that Britain was at war with Germany.

Blood-Redtempest1

Continue reading Tragic London storm marked slide into WW1

50 years of London heatwaves

Ask a dozen people what they think is a heatwave in this country and you’ll probably get 12 different answers.

The view across to St Paul's Cathedral from Bankside at low tide by Scott Whitehead
The view across to St Paul’s from Bankside at low tide.

The UK press is always keen to tell us that a ‘heatwave is on the way’ – even if it is March and the heatwave in question brings temperatures no greater than the high teens Celsius.

Although in the UK there is no official definition of a heatwave the World Meteorological Organization description is “when the daily maximum temperature on more than five consecutive days exceeds the average maximum temperature by 5 °C, the normal period being 1961-1990”. In other words that March heatwave would see the thermometer peak higher than 15.3C five days in a row. Pleasant enough – but no big deal.

The Met Office, working with the Department of Health, provides a ‘Heat-Health Watch System’ for England which is triggered when a threshold temperature in the South East is  31 °C by day and 16 °C overnight for at least two consecutive days.

I have vague memories of the weeks of sunshine in 1976 but the hot spells that stick in my mind the most are August 1990, when the UK temperature record was set in Cheltenham, Gloucestershire, and August 2003 when an 8-day hot spell saw the all-time UK temperature record broken when 38.5C was reached at Brogdale, near Faversham, Kent.

eggs on roadLast July, when compared with the previous summers, saw some of the best  summer weather since 2006. But where does last year compare with the good summers of 2003, 1995, 1990 and 1976? I decided to have a look back at the daily records for this area which stretch back to 1959.

I have drawn up a list of all days back to 1959 that have an average mean daily temperature of 23.5C or higher. This shows that there has been 93 such days. However, to qualify for the Met Office’s Heat-Health Watch System – ie two days like this in a row the list narrows. To make my job easier, I have narrowed the list further to 3 consecutive days where the mean has been 23.5C or higher. Though I loathe really hot weather in my experience I can put up with it for a couple of days. It is only when it gets to the third day of hot, sleepless nights that it starts becoming unbearable.

In terms of intensity and hours of sunshine, 2003 comes out on top. Though many people will argue that 1976 is more impressive -that summer, which comes in second, only produced two spells that satisfy my criteria. The first heatwave saw temperatures soar above 31C for six consecutive days from June 23. The start of the second, on July 3, saw Bjorn Borg win the first of five Wimbledon mens’ titles as he prevailed over Ilie Nastase in 35C heat.

The summer of 1995, which saw my driest-ever August with just 0.7mm of rainfall all month, comes in 3rd, with six days of mean temperatures of 23.5C or higher.

Polo advert for the heatwave that coincided with the  Queen Mother's birthday in 1990
Polo advert for the heatwave that coincided with the Queen Mother’s birthday in 1990

Looking at the data another way, ranking the average total daily mean temperature of each spell, sees 2003 again come out 1st, with August 1990 and July 1983, 2nd and 3rd. Looking back through history it is not really surprising that 2003 comes out on top. While  it was hot in London the heatwave across the Channel contributed to the death of over 70,000 people throughout Europe, France being the most affected.

This weekend promises to be very warm and sunny but it will pale into insignificance compared with the hot spells of the past. The mean temperature on Saturday and Sunday is unlikely to exceed 17C. heatwave table

 

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