Category Archives: UK climatology

June 2019: record heat spike

June 2019 saw no high temperature records broken but a jump in anomaly, produced on the 29th by the 3rd hottest June day back to 1959, is higher than any I can find back to that year..

The only phenomena similar that I can find, albeit in the other direction, is the Beast from the East in March 2018 that sent temperatures plummeting.

The month finished a little above average though the final figure, like May and April, masked cool warm spells.

The mean temperature finished 16.9C that’s 0.8C above average, the coolest for 3 years.

Rainfall was 63mm, 123% of average, the wettest for 2 years. Sunshine was 158 hours, 88.7% of average, and dullest for 3 years.

A timelapse of the longest day can be found here.

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

june 2019
‘Feels like’ maxima.
12.1
June 1981-2019 maximum anomalies
june anoms

 

The 12 month rolling rainfall total, thanks to a wetter than average month, has moved above 500mm again.

Summary for June 2019

Temperature (°C):
Mean (1 minute)  16.8
Mean (min+max)   16.9
Mean Minimum     12.1
Mean Maximum     21.7
Minimum          7.1 day 08
Maximum          33.6 day 29
Highest Minimum  18.0 day 24
Lowest Maximum   14.4 day 10
Air frosts       0
Rainfall (mm):
Total for month  63.3
Wettest day      18.7 day 10
High rain rate   20.1 day 09
Rain days        13
Dry days         17
Wind (mph):
Highest Gust     24.4 day 08
Average Speed    2.7
Wind Run         1932.6 miles
Gale days        0
Pressure (mb):
Maximum          1031.5 day 27
Minimum          998.4 day 07
Days with snow falling         0
Days with snow lying at 0900   0
Total hours of sunshine        0.0

 

 

 

 

 

 

 

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The coldest and wettest days of June

Looking out the window on a cold and miserable June afternoon yesterday reminded me of similar such days during the Seventies and Eighties.

But the mind plays tricks and I wondered if these kind of days were that common in the past.

To weed out the also-rans qualifying days had to be sunless with an anomaly that was at least 4C cooler than the daily average and rainfall of at least 12mm.

This gave the following list.

24hrd

So, in the last 60 years there have been only 12 days similar to June 10th 2019. That would give a probability of less than 1% (0.00743)

Looking elsewhere it would appear that there was much more rain to the north, south and west of Wanstead.

rain all

 

 

The curse of June 13th

1 Jun 21 Jun 16 Jun 77

June can be a strange month weatherwise. Scorching temperatures as well as washout, cold weather, perhaps epitomised by the Queen’s Diamond Jubilee pageant on the river Thames in 2012, can feature prominently.

The month can also throw up some striking anomalies, none more so than the fact that the 13th is the only day in the month where the temperature has ever reached or exceeded 30C anywhere in the British Isles.

According to TORRO the highest daily maximum recorded in the UK is 28.3C at Earls Colne, Essex, in 1948; at Brixton, south London, in 1896 and Aboyne in 1994. Yet either side of this date has records comfortably above 31C, as the table below shows.

torro.PNG

The closest we’ve got locally to 30C in the last 60 years was in 1989 when 27C was recorded.

So why is the 13th ‘cursed’ with traditionally being the coolest day of the month? The best explaination perhaps is the fact that the date occurs more or less during the middle of the North-west European monsoon.

According to Philip Eden’s list of singularities the June monsoon can strike any time between the 1st and 21st but normally peaks on the 16th with a 77 per cent frequency.

As well as cool temperatures the phenomenon can also bring copious amounts of rain, as happened in 1903 when large parts of Redbridge were inundated following a 59-hour deluge that started on… the 13th.

Will we see a repeat this Thursday? Unlikely, though the general pattern is not that different to what led to events over a hundred years ago.

13th

 

 

May 2019: average but dry

May finished average though the final figure, like April, masked cool warm spells.

The mean temperature finished 13.2C that’s 0.1C above average and nearly 2C cooler than last May.

Only 28.3mm of precipitation were recorded, 55.3 per cent of the 1981-2010 average.

Some 175.8 hours of sunshine were recorded, that’s 96.8 per cent of average..

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

may tmax.PNG
‘Feels like’ maxima.
may 2019 feels like.PNG
May 1981-2019 maximum anomalies
may since.PNG

 

The 12 month rolling rainfall total has fallen below 470mm for the first time since July 2017.

12 month.PNG

Summary for May 2019

Temperature (°C):
Mean (1 minute)  13.3
Mean (min+max)   13.2
Mean Minimum     8.1
Mean Maximum     18.4
Minimum          2.5 day 11
Maximum          25.3 day 23
Highest Minimum  16.0 day 25
Lowest Maximum   10.9 day 04
Air frosts       0
Rainfall (mm):
Total for month  28.3
Wettest day      7.3 day 07
High rain rate   52.3 day 26
Rain days        11
Dry days         20
Wind (mph):
Highest Gust     20.6 day 04
Average Speed    1.9
Wind Run         1637 miles
Gale days        0
Pressure (mb):
Maximum          1041.8 day 13
Minimum          991.6 day 08
Days with snow falling         0
Days with snow lying at 0900   0
Total hours of sunshine        0.0

Where’s east London’s rain coming from?

April 2019 was yet another dry month. Just under 12mm was recorded, that’s 28 per cent of average.

There has been rain around but the prevailing wind has not been conducive for great amounts to fall here. Last weekend, over a period of 5 days, just 0.9mm fall. Yet Capel Curig in Snowdonia, 200 miles northwest as the crow flies, recorded 130mm thanks to a NW’ly regime.

A look at rainfall in Wanstead back to July 2013 shows that of the 3,550mm recorded just 17 per cent has fallen when the wind was NW’ly.

Because of the topography of the area most of our rain falls when the wind is blowing between SE’ly and SW’ly, a total of 43 per cent.

A westerly is usually reliable for rainfall, however because this area is in the lee of high ground areas such as Hampstead westerlies have delivered just under 8 per cent of that 6-year total.

rain rose

Is it warm, cold or just normal?

Saying how warm or cold a day feels is subjective; one person’s hot day in spring is another’s ‘on the warm side’. Similarly when someone says the temperature on any given day is ‘normal for the time of year’ others will be exclaiming how cold they’re feeling.

The ‘heatwave’ in February was a case in point. Though many places recorded their warmest February maxima on record many were saying it was just a nice, warmer than normal spell of weather.

Some years ago the Met Office issued guidance on how warm or cold a day was relative to the anomaly. Earlier this month the table was posted on Twitter and I have plotted a graph for the spring period.

Today’s (March 22nd) maximum of 11.1C is therefore described as ‘normal’.

temp feel

cold hot warm

 

Data reveal windiest March for 4 years

March 2019 has been a windy month so far. With 11 days to go it is already the windiest March for 4 years and the windiest month for over a year.

The windiest month recorded since 2013 was December 2015.

Looking at the data in general there seems to be a pattern of a windy month that is followed by a decline of between 10 and 13 months.

monthly wind run

 

Spring or still winter? Plants reveal all.

With the record warm spell last month and high sunshine totals you would think that the growing season is well under way. Spring bulbs have been out for weeks, trees are blossoming and many shrubs are on the verge of flushing.

But a look at the local temperature records over the last six years shows that things aren’t as advanced as previous seasons.

Considering the period from December 1st – in recent years a date when it is common to see bulb shoots beginning to emerge – to March 10th reveals the following table in terms of growing degree days.

growing degree days

The warm days of last month were cancelled out by cold, frosty nights, leading to little net warmth. And the last ‘growing degree-day’ was on March 2nd. Nevertheless growth is further on than last year that saw record cold in March. 

The season is a long way behind 2015-16, however, which saw a record-breaking mild December.

Looking at the list below, and the at best average outlook, we’ve still got a way to go before we’ll see most trees in full leaf…

plant development
This list courtesy of Wikipedia

 

 

Winter 2018/19: average with extremes

The winter of 2018/19 will probably be remembered most for the remarkable warmth in the last week of February. And for its lack of snowfall.

The mean temperature finished 6.1C, that’s 0.7C above average, the mildest for 3 years.

Rainfall was below average: 127mm fell, that’s 87 per cent of average and the driest for two years.

Sunshine was well above average: 211.6 hrs is 126 per cent over average, the sunniest for seven years.

The warmest day of the winter occurred on December 30th with 14.2C recorded. The warmest night was on January 28th when the temperature fell to just 10.8C.
The wettest day of the winter occurred on January 2nd when 15.3mm was recorded.

Snow first fell on 5 days between January 22 and February 1st: five days of snow falling and two days of snow lying over the three months is below average.

There were 29 air frosts during the three months, seven above the 1981-2010 average.

A full weather diary is available for the months of DecemberJanuary and February. To view full stats for each month follow this link:http://1drv.ms/1kiTuzv

TMax winter

Summary for period 01/12/2018 to 28/02/2019

Temperature (°C):
Mean (min+max)   6.1
Mean Minimum     2.6
Mean Maximum     9.7
Minimum          -6.5 on 30/01/2019
Maximum          18.7 on 26/02/2019
Highest Minimum  11.5 on 06/12/2018
Lowest Maximum   1.3 on 23/01/2019
Air frosts       29
Rainfall (mm):
Total for period 127.0
Wettest day      11.4 on 20/12/2018
High rain rate   28.1 day 26/01/2019
Rain days        31
Dry days         59
Wind (mph):
Highest Gust     31.1 on 09/02/2019
Average Speed    2.8
Wind Run         6152.3 miles
Gale days        0
Pressure (mb):
Maximum          1043.8 on 02/01/2019
Minimum          980.4 on 01/12/2018
Days with snow falling         5
Days with snow lying at 0900   2
Total hours of sunshine        0.0

Ben Nevis: a serious mountain

Strong winds, hail, sleet and snow were experienced in abundance when I climbed the UK’s highest mountain at the weekend. ben start

To give us a chance of making it to the 1,345m summit and back we left Fort William in darkness. Heavy rain that had greeted our arrival the previous day had abated but the spooky balminess of this early January remained; a local thermometer was reading 11C at 7am!

A gorgeous purple hue tinged the early morning dawn as we began our ascent though it was not long before the rain returned.

 

Proceeding upwards, after about an hour, we passed another climber who was walking down, having abandoned his attempt because of ‘atrocious conditions’. “I’m more of an ice and snow climber,” he explained, telling us how wonderful conditions had been in Zakopane, Poland, just a few days previous.

Unperturbed we pushed on soon making it to the tarn – the Lochan Meall an t’Suiche. We had ideas to climb the Ben via the Carn Mor Dearg arête but a wrong turn and conscious that time was not on our side we turned back and continued on the pony track / tourist route. Just over two hours in we passed the ford, just below which the route begins zig-zagging its way up to the summit.ben tarn

By now the rain started to get heavier. At around 900m it turned to hail. It was at this point that we passed another climber: “It’s snowing on the summit but you don’t need crampons,” he exclaimed before hurrying on down. We passed a further dozen or so walkers on our way to the summit; all of them looked like they couldn’t wait to get off the mountain. The rain was now a wintry mix of hail, sleet, snow and frozen rain – painful to walk into in the strengthening wind.

ben paul bothyAs the peak started to level out around 1,150m snow was now beginning to settle on the rime that had built up on the cairns; we’d got what we’d come for! It was here, however, that I realised my waterproof trousers weren’t so waterproof. First dampness then rivulets of water began flowing into my boots.

The peak was now well fogged in and for the first time I felt a bit uneasy, conscious of the fact that the wind was also still gathering strength. Regardless, my climbing pal continued to press on just ahead of me. Poor visibility concealed the summit which was still another 100m or so higher. Although he’d previously climbed the Ben (in perfect summer conditions) he’d forgotten exactly where the trig point was and was careful to observe the cornices to the side, so lethal to inexperienced walkers who fall through them every season.

We made a beeline for the bothy close to the trig point; my climbing partner, who was also trying to deal with waterlogged boots, was keen to change socks. At that point a gust of wind caught the bothy door – it smashed open leading to the rime that had built up on the hut to fall to the ground. I was starting to feel well out of my comfort zone and I persuaded him against the sock change, saying we needed to turn around and get down as quickly as possible. Despite both having crampons in our rucksacks I decided against spending more precious time trying to wrestle them on to our boots. Although the ground was coated in rime I knew that the warm front that was coming in was already lifting the temperature – and we’d cope without them.

ben paul trig

The route down was easier if unpleasant. Once we’d descended far enough out of the cloud and wind I knew we’d be OK and it was just a case of taking it steady over the uneven cobbles.

Night was fast drawing in by the time we arrived back at the Ben Nevis Visitor Centre. As we called a cab for the short drive back to Fort William all I could think about was a hot bath back at the hotel and a welcome pint by the fireside.

All around Fort William it is frequently mentioned that conditions at the top are totally different and that the Ben should not be under-estimated. As someone with nearly four decades of experience of being in and around mountains I should know better than most. But Ben Nevis is not just any mountain and deserves complete respect.

The meteorology of the climb

aonach
The temperature trace shows that the warm front arrived after 11am
aonach wind
The WSW wind was gusting F6/F7 giving a windchill of -5C and lower

* Despite the awful conditions I did manage to get a few photos, including the observatory where Victorian scientists lived for 20 years, gathering meteorological observations until 1904. Experiencing just a taste of the conditions that they would have had to endure makes their achievement all the more remarkable.
The observations have recently been fully collated and are providing valuable insight into the study of how mountain conditions have changed since that time.

** The following article was printed in the Lochaber News, 9th January, 2013

Stupidity can get you killed

The leader of Lochaber Mountain Rescue Team has issued a strongly-worded warning in the wake of a walker’s “act of sheer stupidity” in trying to tackle Ben Nevis in winter in trainers.

John Stevenson (58), who heads up Britain’s busiest mountain rescue unit, said a man rescued on Monday afternoon was fortunate to be alive after attempting the country’s highest peak without proper equipment for the conditions and time of year.

The 31-year-old walker was airlifted to hospital in Fort William after he fell while descending the 4,409ft, snow-covered Ben. He sustained a leg injury while walking on the main mountain track and managed to alert the police to his situation at about 4pm.

A full search and rescue operation was launched involving police, 18 mountain rescuers and a Royal Navy helicopter from HMS Gannet, Prestwick.

The injured man was located and airlifted from the Red Burn area, above Lochan Meall an t-Suidhe, and was treated at Belford Hospital for his injury and the effects of the cold.

Mr Stevenson said the incident could have turned to tragedy.

He said: “He’s an extremely lucky young man to have survived.”

“His equipment was just rubbish – he had nothing. He was wearing trainers and didn’t have a torch.”

“He did everything we tell people not to do. When we found him he’d lost one trainer, the backside was out of his trousers and he was wet and cold.”

“There’s no doubt in my mind that he would not have survived the night if he hadn’t phoned in on his mobile, and we were lucky enough to find him.”

“He didn’t actually set off on his ascent until 11am, having come straight off the train at Fort William. That’s just a ridiculous time to be starting out when darkness falls at about 4pm. It’s crazy and not on at all.”

“He made it to the summit okay but slipped on the way back down and managed to call the police on his mobile phone.”

Mr Stevenson added: “Initially he was on the so-called tourist path but he lost his way and veered off the path.”

“He slipped and hurt his leg but kept on walking – but realised he was lost and phoned the police.”

“He was talking to the police as he walked and then the phone just went dead. All the officer could hear was running water.”

“We had been alerted by this time and were on standby, so when the line cut out we all feared the worst.”

“I knew the only place on the top half where you can hear water running like that is the Red Burn, so we sent two members of the team up with the helicopter, as well as members on foot. Luckily the first two found the casualty pretty quickly. He had fallen but was okay. He’d lost his phone.”

Mr Stevenson said he found it increasingly frustrating that, despite annual messages from rescue teams, climbing organisations and the police, walkers were still heading to the mountains ill-equipped for the conditions.

“People need to be prepared,” he urged. “They need to heed the advice about having proper equipment and clothing.”

“The thing is, so many people get away with it every year, but unfortunately many don’t and end up injured – or worse.”

“The man on Monday was very lucky indeed and we could see he was extremely relieved to be off that mountain.”

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