Storms in late February / early March occur in 88 per cent of years, according to Philip Eden’s study on singularities.
This year looks no different although the drop in air pressure looks like it will happen just in the nick of time.
A look at the past eight years shows the effects of the pattern are quite pronounced.
And a look nationwide reveals the following named storms occurred around this period.
And going back further reveals a notable storm in the 19th century.
Attention on the bright meteor seen over the UK earlier this week got me thinking about the meteors frequently mentioned in Luke Howard’s Climate of London volumes.
Howard had a keen interest in all things atmospheric, not least this celestial phenomena. Many of his personal accounts are mentioned over a period of a decade or so including accounts of meteors overseas.
April 4, 1807
February 1, 1808
July 12, 1808
December 16, 1808
March 22, 1809
May 1, 1809
July 18, 1809
January 26, 1811
April 1, 1811
November 7, 1812
April 23, 1813
July 29,1813
February 2, 1816
December 12, 1816
August 6, 1817
Decenber 8, 1817
January 28, 1818
February 6, 1818
The last three months in east London, considering sunshine, have been the dullest for 10 years. Despite the sunny end to February just 123 hours of sun have been recorded, just under 74 per cent of the seasonal average.
With little sun, rainfall well above average, temperatures best described as average and the endless lockdown it is no wonder things felt so grim.
A couple of years ago, inspired by the blogger XMetman, I devised my own ‘grim index’ to try to rank how each winter ‘felt’.
Using the same criteria, and assuming that most people welcome sunshine, it can be seen that since the least grim winter of 2007-08, the season, after a blip in 2018-19, has been growing steadily worse.
The grimmest winter, considering statistics back to 1881, was, ironically, the 1978-79 ‘Winter of Discontent’ when, again ironically, ‘Sunny Jim’ Callaghan was in Downing Street as widespread strikes coincided with the coldest winter for 16 years.
On looking at the Top 20 of grim winters it is striking how most coincide with depressing world events, the Great War, World War 2 and the Spanish Flu pandemic.
Early March often brings stormy weather, a singularity that has a probability of 88 per cent!
An example of just how long this singularity has been around can be found in the early 19th century
In his book The Climate of London Luke Howard mentions that the air pressure on March 4th was the lowest measured for some 37 years. The lowest point of 28.35 inches (960mb) is remarkable in that the lowest I’ve measured in Wanstead since 2012 was 969.8mb last December!
The storm brought devastation across a wide swath of southern England with loss of life on both land and sea.
Howard’s account of the storm mentions the barometer falling an inch in 15 hours with rain after dark with the wind “raging in violent gusts from SE and SW till past midnight when it abated after much thunder and lightning”.
His friend in Manchester, Dr William Henry, wrote a storm SW caused considerable damage, delaying the London mail in Macclesfield from 8pm until 3am on the 5th, the storm raging until 3am. The barometer fell to 28.2in (955mb) at Manchester.
Character of the period for the most part tempestuous with frequent rains the barometer running through a series of sharp depressions till near the close when it suddenly assumed the elevation of fair weather Almost all the showers from the first were more or less mingled with hail
Elsewhere in Britain public ledgers also reported the storm.
Yarmouth A most tremendous gale of wind from the S to the SE with rain came on about 8pm which continued with increasing violence all night and has done considerable damage to the shipping on this part of our coast.
Deal Last night it came on to blow a most tremendous gale from the south and continued nearly the whole of the night with unabated violence at midnight it blew a complete hurricane accompanied with thunder and lightning during which several vessels in docks suffered.
Portsmouth It blew a tremendous hurricane last night from S and SSE accompanied with the highest spring rides ever remembered.
Ryde One of the severest gales of wind that has been felt here for the last 37 years was experienced last night. It commenced about 4.30pm and continued with increased violence until past 11pm during which time the greater part of the pier and several houses were demolished. The supposed damage is estimated at between £4,000 and £5,000. No lives were lost nor any damage done to the shipping.
Dartmouth We experienced a perfect hurricane last night at SSE from 6pm to 10pm
Exmouth On the 4th instant between 7pm and 8pm we had a most tremendous gale of wind about SSE with dreadful rain thunder and lightning.
Falmouth At day light this morning the wind was from the WSW moderate. About 11am it strengthened to the S and from that to SSE and since that time until 10pm it has blown a hurricane with a heavy sea.
Penzance We had a very heavy gale here on Wednesday the 4th.
Milford On the 4th it blew a very heavy storm from SW to WNW.
Leicester Wednesday night was one of the most boisterous recollected for years past. Much damage has been sustained in this town and many parts of the county.
Hull At high water about 4.30pm the wind then blowing from the SW with moderate weather the tide flowed at the Old Dock Gates 18ft 6in. After the tide had fallen from 1 to 2in the dock gates closed as usual with the ebbing of the tide which then began again to flow to the height as near as can be calculated of four or five inches thereby opening the gates again and continued flowing. The tempestuous night of Wednesday ensued the wind blew a heavy gale still from the SW and at high water at 5am Thursday morning the tide was 14ft 1in being 4 feet 5 inches less than on the preceding evening although from the spring tides having put in the water ought according to the usual state of things to have flowed higher than on the Wednesday evening
Plymouth At the commencement of the winter a few large stones were placed by themselves on the top or finished part of the Breakwater to see if they would stand the winter gales they stood all but this last and this morning I found them washed from the top and lying on the North Slope There were three of them one of nine tons and the other two of five tons each they will be replaced as soon as possible for further trial Plymouth The effects of the late thunder storm of the 4th March on a fir tree belonging to W Langmead Esq at Elfordleigh in the neighbourhood of Plymouth are too singular to be omitted and perhaps the most extraordinary ones that ever occurred in this county on such an occasion The tree in question has been long admired for its size and noble proportions being more than 100 feet high and nearly 14 feet in girth but it exists no longer having been literally shivered to pieces by the electric fluid Some of the fragments lie 260 feet from the spot and others bestrew the ground in every direction presenting altogether a scene of desolated vegetation easier to be conceived than described.
Valentines Day 2021 saw the cold spell come to an end in the London area. Maxima over the past 7 days never exceeded 2.3C on any day, the yardstick I use for a spell of cold weather to qualify.
Though some places did get a decent amount of snow precipitation in this area was very low ; lying snow at 9am at this station never exceeded 3cm. Very cold, dry air however was enough to preserve cover out of the sun.
As cold spells go it was two days longer than the median of 5 days, so slighter colder and drier but with double the amount of sunshine.
A couple of years ago I tried to rank cold spells in this area since 1960, with mixed results. I’ve since revisited the method and have achieved better results using the following algorithm.
(Number of days * total precipitation)*(mean temperature of spell)-(total sun hours). This gave the following list.
And the next 26 cold spells
There’s been many images that define this spell but this post probably nails it in that I’ve never seen the ice thick enough on the marshes to tempt someone to ice skate.
With the midnight run of this model bringing the start of the 25th into range the prognosis for the big day is a rare white one – for those north of the border.
The rest of the country is messy mix of sleet and, in London’s case, cold rain with a high of 7C. It looks fairly average for this locality!
But followers of this blog and elsewhere will know that any model output beyond 72 hours should be taken with a very large pinch of salt.
But while conditions out to 15 days are often very different they can give a general guide to how the atmosphere is evolving in the medium range. The last few winters I’ve been doing this Christmas day model blog have revealed that conditions are sometimes not wildly different from what was hinted at 372 hours before.
Over the last few days the GFS, and other models, has been flip-flopping between cold and mild, a symptom of the current atmospheric situation which suggests that the polar vortex may undergo displacement as we progress further into winter. This could signal colder weather for NW Europe – but exactly where this colder weather will be as we progress to the end of the month is very uncertain – any colder than average weather could remain closer toward Central Europe, as happened in 2008.
Below are charts for each day from the midnight operational run of the GFS model.
The best chance for lying snow this winter looks like being at the end of the second week of January.
A combination of local analogues and global atmospheric factors including the El Niño-Southern Oscillation suggest that the coming season will be colder than recent years. Though that’s not saying much considering just how mild winters of the past decade have been.
Meteorological autumn was the warmest for 5 years and slightly drier than last year’s wet autumn. Though it shares some similarities with 2015 the external influences are thankfully different to that season which produced the warmest December on record. Considering data back to 1797 I was able to make the following suggestions on how the next 90 days may unfold.
December is most likely to be around average temperature-wise with rainfall also about average. Possibly stormy at the end of the first week. Any snowfall events are likely to be marginal – bad news for anywhere below 70m above sea level. In terms of Christmas a white one in London looks unlikely. There may be interest in the week running up to the big day but I wouldn’t be surprised to see that inexplicable warm up that often happens just as the 25th arrives.
Mean: 5.8°C (5.6°C 1981-2010 average)
Rainfall: 57.1mm (53.2mm 1981-2010 average)
January is the month most likely to see any lying snowfall, particularly during the first half of the month, with the mean temperature about 1C colder than average. Rainfall is likely to be above average.
Mean: 4.1°C (5.2°C 1981-2010 average)
Rainfall: 63.8mm (53.2mm 1981-2010 average)
February looks wet and mild overall.
Mean: 6°C (5.3°C 1981-2010 average)
Rainfall: 55.6mm (39.2mm 1981-2010 average)
Overall the mean for winter: 5.3°C, a little below average.
And rainfall about 120 per cent higher than average.
Looking in closer detail reveals that the coldest period is most likely to be between 13th and 19th January, with anomalies sufficiently low enough for lasting lying snow.
The extremes that no-one can forecast
As well as the extreme December 2015 the analogues also revealed the severe season of 1822-23 which saw ice on the Thames by late December. February 8th saw a great snowstorm in northern England where people had to tunnel through the snow.
Another was 1950-51 which was very snowy at high levels. There were 102 days of lying snow at Dalwhinnie (1000ft), exceeding the 83 days set in 1946-47. December 15th saw 15in of snow in Shanklin, Isle of Wight in 3.5 hours.
Frost is a rare beast this year, even in the Wanstead Park frost hollow.
So far this year I’ve recorded just 82.5 hours where temperatures at 4ft (1.2m) were -0.1C or below. That’s just 37 per cent of what is recorded in an average year. And would suggest that frosts in December will be above average.
The lack of frost this year is even more remarkable given that the past seven years, especially the winters, have been so mild.
A closer look at the data shows that winter months are no guarantee of seeing temperatures fall below freezing. The record mild December 2015 and February 2014 are testament to that.
The fact that January 2017 looks the most remarkable month for frost reveals just how mild recent years have been.
Snow is ever present in the UK in most years though you have to look hard to find it in high summer.
A dedicated group of enthusiasts, led by Iain Cameron, chart and catalogue these snow patches – many of which are hidden or only seen as distant white dots during Scottish Highland walks.
Responding to an appeal in September I met up with Iain and other volunteers to chart the patches in Observatory Gully on Ben Nevis, the UK’s tallest mountain.
Our route up in the shadow of the magnificent north face of the Ben was a warm one; to our left a procession of ant-like figures were tracking the CMD arrete route to the summit, walkers making the most of the amazing weather.
Out of the sunshine it was noticeably colder in Observatory Gully; being north facing it sees very little of the sun even in mid June, slowing down the rate of melt of the snow which can be tens of feet thick by the end of the snowfall season. Being encased in snow for so long obviously has a chilling effect on the rock.
The walk up on the scree was hard work and I was surprised to see so many debris including parts of large parts of old galvanised chimney cowls, the legacy of the observatory that once sat proudly on top of the Ben. Not many people trek this way, being a bit of a cul-de-sac. To reach the 1,345m summit from here requires a 200m climb at the end.
As we edged higher the dot of snow grew ever larger and is surprisingly big by the time we reached it, Iain was surprised how hard the snow was. From Iain’s reports, published in the Royal Meteorological Society’s Weather magazine, I’d been fascinated by the images of the patches with naturally carved tunnels underneath them; the light inside the ‘cave’ has a gorgeous blue hue to it.
It was at this moment that I realised that this was a large part of the draw of tracking these patches; a fascination with snow in an area where the odds of it existing all year round seem to be forever diminishing.
Seasons of melt and snowfall
Snow has only vanished entirely in Scotland six times. Three of these occasions were in 2003, 2006 and 2017.
Mean temperature statistics from Cairngorm Summit show just how much the seasons can vary. Of course mean temperature is just one variable that affects snow survival rates. For example the Western Highlands saw huge amounts of snow fall in February and March above 300m, a factor that would have helped snow survive. Though the most recent melt season was 0.4C cooler than 2019 there was probably a far greater volume of snow.
* Because of the unreliable nature of mountain-top records the Met Office data for Cairngorm Summit has some large gaps, it is only the last 5 years that have complete records . I discounted any years that were missing more than 5% of data.
The wettest October since at least 1797 was recorded last month with some 159.2mm collected, 238 per cent of average.
The month started wet with the daily October rainfall record also broken with 49.1mm on the 2nd, the wettest day ever recorded in the UK.
With all that rain sunshine was at a premium; the 51.6hrs recorded was the second lowest October total since 1881. Only 1894 was duller.
The monthly mean was 11.7C, 0.1C below average.
Does any of the above have any bearing on what we can expect this winter? Possibly, but there are so many variables to consider.
Looking at rainfall patterns alone would suggest mean temperatures in November being a degree cooler than average and December broadly average.
Rainfall in November average while December is slightly below.
