Tag Archives: London

London weather, Monthly Review, monthly summary, Weather

July 2017: wettest since 1960

August 1, 2017 wansteadmeteo 1 Comment

July 2017 was the wettest since 1960. Some 92.3mm of rain were recorded which is 212 per cent of the 1981-2010 average.

Although the opening third of the month saw a continuation of the June heatwave temperatures gradually returned to normal values to leave the mean for the month at 19.2C, that’s 0.7C above average.

With all the rain sunshine totals were down. Some 167 hours were recorded, that’s 87% of average.

Though the rainfall total was impressive it is well short of the record of 164.2mm set in 1834, and is only 35th in the list going back to 1797.

Summary for July 2017

Temperature (°C):
Mean (1 minute) 18.9
Mean (min+max) 19.2
Mean Minimum 14.7
Mean Maximum 23.7
Minimum 9.4 day 12
Maximum 30.5 day 07
Highest Minimum 18.3 day 06
Lowest Maximum 19.0 day 24
Air frosts 0

Rainfall (mm):
Total for month 92.3
Wettest day 30.8 day 11
High rain rate 56.4 day 29
Rain days 10
Dry days 21

Wind (mph):
Highest Gust 17.4 day 27
Average Speed 2.9
Wind Run 2163.5 miles
Gale days 0

Pressure (mb):
Maximum 1024.2 day 16
Minimum 996.8 day 31

Total hours of sunshine 167

In terms of the rest of the summer a look at the ECMWF control run out to 10 days suggests an unsettled start to August with the jetstream centred right over the top of the UK. Things may improve as the Azores high attempts to exert more influence – so perhaps more in the way of sunshine than of late. In terms of heatwaves it is impossible to tell at this range.

Here follows the full weather diary for July. To view full stats follow this link:http://1drv.ms/1kiTuzv

1st: Cloudy but with sunny spells developing, these growing longer in length by evening.
2nd: Sunny with just a few light cumulus.
3rd: Sunny start though with plenty of cloud around, this tending to thicken after lunch with odd spot of rain.
4th: Sunny and very warm early then tended to cloud over before sun returned in the late afternoon and evening. Some very unstable low to mid level cloud.
5th: Sunny with just a few cirro-cumulus. Feeling very warm with cloud bubbling up in the evening, however forecast storms failed to materialise.
6th: Sunny with cirrus and dotted cumulus. This tended to thicken late morning though sun stayed out and became hot and humid.
7th: Sunny with lots of high-level cirrus and cumulus most of the day.
8th: Bright but mostly cloudy start, the cloud tending to vary through the day. Sunny after 4pm. Warm overnight.
9th: Bright but mostly cloudy start, the cloud tending to break and vary through the day.
10th: A mostly sunny morning and lunchtime until 2pm when it clouded over.
11th: Cloudy with some bright breaks at first. Cloud thickening with rain by noon, this falling sporadically before getting going after 5pm and stopping by 3am.
12th: Cloudy, damp and close start.
13th: Sunny with variable cloud until noon when there were just bright spells.
14th: Cloudy but with a few breaks around mid morning. Turning cloudy again before sunny spells in the evening.
15th: Cloudy with some sporadic rain as warm front blew through and close. Very limited brightness.
16th: Cloudy with some bright spells. Feeling warm and humid.
17th:Sunny with just a few cirrus drifting around. Feeling hot, cloud thickened from the west in the late afternoon.
18th: Sunny with variable cirrus and cirro cumulus through the day. Feeling very warm. Storms began building with supercell to west of London and over Chilterns.
19th: Cloudy, dull start and very humid with heavy mist – the cloud tended to lift to give sunny spells in the afternoon.
20th: Drizzle after shower before obs time, then showers through to 1pm.
21st: Cloudy start but with sunny spells developing. Clouded over in evening with intermittent heavy rain at 11pm and through the early hours.
22nd: Cloudy but with sunny intervals developing around noon. Heavy showers developing with thunder at 2.30pm and 3.07pm.
23rd: Bright with variable cloud
24th: Cloudy with light, showery rain from northerly airstream that originated in the Med.
25th: Cloudy with light rain just after obs time.
26th: Cloudy with occasionally rain. Feeling warm and a late clearance. Breezy and chilly overnight.
27th: Cloudy but bright and sunny spells developing. A very heavy shower at 1pm.
28th: Bright start but clouding over.
29th: Sunny start with cloud increasing after noon to leave overcast before patchy rain moved in. This falling more heavily at 5pm before clearing to further showers. More rain overnight before a strong squall arrived at 2.45am and lasted an hour with further bursts of rain through the night – two claps of thunder and lightening during squall.
30th: Sunny with variable cloud through the day. Very warm in the sunshine
31st: Sunny with variable cloud throughout the day.

Heathrow weather, Heatwaves, History, London weather, Weather

Phew! What a scorcher…

July 6, 2017 wansteadmeteo 2 Comments

I’ve seen this phrase uttered more than once over the past couple of days thanks to high temperatures and humidity. But ask anyone to define a hot day and you’ll get a different answer every time.

Growing up in the 1970s / 80s redtop newspapers would use the phrase once the mercury was nudging 80F (26.7C). But to ‘scorch’ you need sunshine, preferably at least 10 hours of it. Considering statistics from the Heathrow airport climate station in west London there have been 463 scorchers since 1959, the most recent happening on July 5th with 29.5C recorded and 13.9 hours of sunshine. There have now been 9 scorchers this year, already matching the number that were recorded in 2014 and only 3 short of last year.

But even with last month’s heatwave this year has some way to go, however, to match the amount measured in 1976 and 1995: 31 days!

Monthly Review, monthly summary, Rainfall, Weather

December 2016: driest for over 80 years

January 5, 2017 wansteadmeteo 1 Comment

December 2016 was the driest 12th month in over 80 years and the 5th driest in a record going back to 1797.

screen-shot-2017-01-05-at-17-12-19 — Christmas day was the second warmest on record in London

The total fall of 8.3mm is just 16 per cent of what normally falls in December, marginally more than December 1933. The mean temperature of 6.1C was 0.5C above average, though 4C colder than the record December last year.

There were 51hrs of sunshine, that’s 125 per cent of average.

The wettest day was on the 10th when 5.2mm of rain fell. The warmest day occurred on the 9th with 14.2C recorded. The lowest temperature occurred on the 28th when the spirit fell to -4C.

The sunniest days were on the 4th and 29th when seven hours of sunshine were recorded.

Air frosts: 8, Ground frosts: 14

screen-shot-2017-01-05-at-17-12-44 — Fog, frost and black ice all featured during December

Though January has started on the chilly side in the short term the weather will turn mild. Beyond that there is a suggestion that the weather could turn on the colder side of average with some models suggesting a cold snap with snow around mid-month.

My usual method of prediction to the end of the month has been scotched by the very dry December. The only years that were similar were both far colder than last month – the usual pattern of a dry month being cold or very cold was broken.

With the unprecedented warmth at the North Pole, last year’s odd behaviour of the QBO and a weak polar vortex we are in unprecedented territory in terms of what could happen later in January. My hunch, though, suggests the month will end up average to rather cold with little precipitation. Any cold spell with probably be the short-lived variety with a couple of inches of snow that lasts three days.

So, to sum up, we’re looking at a mean of 4.4C, rainfall: 55mm, sunshine: 39hrs.

In view of the above my forecast last month was very poor: predicted mean 4.4C (result 6.1C). Rainfall: 55mm (result 8mm). Sunshine: 39hrs (result 51hrs)

I have also published a winter forecast covering the London area that you can find here.

Here follows the full weather diary for December…Full stats for the month here:http://1drv.ms/1rSfT7Y

1st: Sunny start though the frost lifted readily into low cloud and mist to leave a chilly afternoon.
2nd: Cloudy, quiet and cool weather all day.
3rd: Cloudy and quiet all day. Feeling cold.
4th: Sunny , frosty start. Quickly warming up to leave sunny, cloudless afternoon.
5th: Sunny start, then patchy cloud – this thickening before becoming foggy overnight.
6th: Misty start after fog overnight. Cloudy most of the day though there was a brief clearance around midday.
7th: Cloudy most of the day though there was occasional brightness.
8th: Dull day though with a little limited brightness early afternoon.
9th: Cloudy but wth more brightness than yesterday. Very mild. Cloud thickened with light rain around 11am. This gradually grew heavier as the day progressed and was moderate overnight.
10th: Bright start and feeling mild, then cloudier and damp.
11th: Cloudy and dull all day.
12th: Dull all day with light rain early and late. Clearer spells overnight but overcast again by dawn.
13th: Dull with bits and pieces of drizzle up to 11.20am.
14th: Bright start with lots of cirrus and altocumulus – this gradually cleared to leave a warm and pleasant afternoon.
15th: Dull and cloudy with limited brightness.
16th: Dull and cloudy start.
17th: Foggy and dull all day.
18th: Misty start with fog above 90m on cycle ride. Then dull and grey all day. Mild.
19th: Dull and cloudy all day – some spots of drizzle.
2oth: Sunny start but clouded over late morning. Cloudy thereafter with some drizzle overnight.
21st: Cloudy start then sunny. Cloud returned and turned dull and dreary in the afternoon with odd drizzle.
22nd: Bright, misty start
23rd: Cloudy start with breeze beginning to build as a result of Storm Barbera.
24th: Cloudy and dull all day. Very mild. Temp increasing overnight with approach of warm front .
25th: Cloudy, breezy start. Remained dull all day though brightness was seen over the Thames and North Downs, disrupting the SW’ly flow.
26th: Sunny, hazy start and turning colder.
27th: Sunny, frosty start, the air pressure record of 2012 has been broken.
28th: Foggy start, the fog persisting to late morning before sun broke through leaving a chilly afternoon. Frost returned quickly after dark, a clear night.
29th: Sunny and very cold and frosty start. Frost returning after dark with fog forming in the early hours.
30th: Foggy and dull all day, the fog thickening up at nightfall. Approaching cloud lifted the fog and temperature.
31st: Dull and overcast to start – this sticking around all day.

Christmas, Christmas Day weather, cold spell, Earthquakes, History, thunderstorm, Uncategorized, Weather in 1810

Christmas 1810: stormy then very cold

December 17, 2016 wansteadmeteo Leave a comment

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.

screen-shot-2016-12-16-at-18-57-08

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.

screen-shot-2016-12-17-at-20-48-37

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’.”

month ahead forecast, Weather

November 2016: record sunshine, cool

December 2, 2016 wansteadmeteo 2 Comments

November 2016 was the sunniest in a record going back to 1881. Some 91 hours were recorded, 156 per cent above average and a complete contrast to last November which was the dullest for 47 years.

frost — The temperature in the early hours of the 30th fell to -6.1C, colder than any night last winter and the coldest since January 2013

The mean temperature for the month finished 6.4C, that’s 1.5C below the 1981-2010 average ; 4C cooler than last year and the coldest November since 2010. The warmest day occurred on the 15th with 15.9C recorded. The first air frosts of autumn were recorded. The lowest temperature occurred on the 29th when the spirit fell to -6.1C.

Rainfall was 135 per cent of average with 80.1mm recorded. The wettest day was on the 19th when 23.5mm of rain fell.

The sunniest days were on the 2nd, 13th and 25th when eight hours of sunshine were recorded.

Air frosts: 4, Ground frosts: 19

stingjet — The dolphin-shape of this radar image shows Storm Angus before it hit the south coast. The system stayed far enough south of us not to cause any damage in London

What has December got in store weatherwise? The models suggest the high pressure that has been anchored over us, bringing cold nights, will pull away to the continent. This will allow an ever milder but mostly dry source of air off the Atlantic through to mid month. Days will grow milder while frost and fog will feature less at night.

Beyond the grasp of the models my long range outlook method suggests an cold month is most likely at 43 per cent probability. Average comes in at 29 per cent probability while rather mild and rather cold are both 14 per cent probabilities.

Rainfall looks finely balanced. Wetter and dryer than average both come in at 43% probability while average is 14 per cent. Given the influence of high pressure at the beginning of the month I’m inclined to think it will be a drier than average month.

So, to sum up, we’re looking at a mean of 4.4C, rainfall: 55mm, sunshine: 39hrs.

My forecast last month was good: predicted mean 6.8C (result 6.4C). Rainfall: 55mm (result 80mm). Sunshine was way off, however – predicted total: 41hrs (result 91hrs)

I have also published a winter forecast covering the London area that you can find here.

Here follows the full weather diary for November…Full stats for the month here:http://1drv.ms/1rSfT7Y

1st: Cloudy and mild all day. Patchy drizzle at times.
2nd: Sunny, cold start after first ground frost of the autumn.
3rd: Sunny, cold start with cirrostratus and cumulus drifting around. Cloud thickened through the afternoon with some light rain around 9pm.
4th: Cloudy, dull start up to 11am. Rain pushed in and lasted for much of afternoon, clearing in evening.
5th: Cloudy, cold and damp start. Some brightness though with a cold wind.
6th: Sunny, cold start, tending to cloud in. Rain after 3pm. Feeling cold but too windy for a frost overnight.
7th: Sunny, cold and very breezy to start, the cloud tending to fill in through the day. Clearer overnight though too much cloud and occasional air prevented an air frost.
8th: Sunny and cold start. Cloud thickened during the day to bring rain after dark at 8pm that then fell through the night – the biggest fall since Brexit day.
9th: Light rain slowly clearing to cloud.
1oth: Cloudy start with light rain showers around 10.30am then cloudy. Some sunny intervals in the afternoon. Milder.
11th: Bright start with cloud decreasing through the morning to leave a pleasant and clear afternoon.
12th: Miserable and rainy to start, this lasting past 11.15am. Drizzle thereafter into 6pm.
13th: Sunny start though cloud tended to fill in through the day. Damp overnight with patchy drizzle.
14th: Cloudy and damp start with some breeze. Brief brightness at noon but patchy drizzle moved in around 4pm.
15th: Cloudy and miserable though very mild.
16th: Sunny start and very mild though cloud tended to fill in during the day making the sunshine milky.
17th: Bright, breezy start, the breeze increasing until a squall blew through at 2.40pm then sunny spells.
18th: Bright start with milky sunshine then tending to cloud over. Feeling cold.
19th: Bright sunshine though cold to start. Patchy altocumulus developed through the day, leaving it to become bright, the strength of the sun diminishing. Rain started around 6pm and fell through night with varying intensity.
20th: Dull and cloudy start with rain returning at 10am. Cloudy afternoon with rain returning late evening and through the night, some heavier bursts.
21st: Cloudy with showers past noon. Heavier showers moved in mid afternoon and fell into the evening.
22nd: Cloudy with a few very light showers around. Breezy.
23rd: Cloudy and breezy. Feeling mild.
24th: Cloudy and mostly dull with brief brightness at noon.
25th: Sunny with just a few cumulus around.
26th: Sunny start but low cloud blotted out the sun around midday then cloudy and cool.
27th: Cloudy and mild.
28th Sunny all day with just a few cumulus floating around.
29th: Sunny all day with frost persisting on grass in shade.
30th: Sunny and very frosty start. Frost persisting on the grass all day with a very cold start to the night. A veil of cloud crossed the region late evening, lifting the temperature above freezing, before clearing before dawn

Forecast, Weather, weather pattern, Winter forecast

London winter forecast 2016/17

November 30, 2016 wansteadmeteo 2 Comments

Frost still lingers on my lawn as I write this winter forecast on the last day of the meteorological autumn. Last night’s minimum was -6.1C, the coldest night this year and, indeed, colder than any night last winter.

It would be very easy to get caught up in the hysteria that happens every November of what the winter will bring. Most of the hysteria comes from ‘coldies’, those folk that hope every winter will be the coldest and snowiest on record. I count myself among them.

screen-shot-2016-11-30-at-11-37-53 — The north-west of England looks around 10C above average on December 9

But, despite hints from BBC weather forecasters that something maybe afoot in terms of something colder than usual from mid-December, years of disappointment have taught me to just take winter as it comes. Meteorological models this morning look anomalously warm for the first half of December, the UK being on the warm side of an anticyclone centred over France – the theme of so many winters I can remember.

The current phases of ENSO and QBO suggest that their influence on our winter this year will be far less marked than last year. Looking at teleconnections with a slight La Nina and the current QBO cycle have revealed winters that were fairly uninspiring though by no means write-offs for snow, two examples in the case of QBO being 1985/86 and 1990/91 – both had very cold Februaries.

Before I got too bogged down with trying to find patterns here I decided to move on to my more traditional pattern-matching.

Before I trawled through the figures my initial gut reaction to this winter was that it would be the coldest for at least four years – a not-too-difficult feat giving the mildness of the last three winters which saw very little in the way of snow.

winter201627 The overall mean temperature for December, January and February came out at as 4.2C – 1.2C colder than the 1981-2010 average, with average precipitation.

A rather cold winter, over three months doesn’t tell you much. A very mild and stormy December could mask a dry and notably cold February. This makes it worth looking at the individual months of each winter.

There is a lot of spread in the above tables. Considering them altogether I would guess winter will unfold in the following way:

December to start mild, possibly becoming very mild, before beginning to turn very cold mid-month. This pattern will persist, with varying intensity through into January which could also be very cold. Milder conditions to follow in February though this will probably end a fairly average month and drier after a slightly wetter than average December and average January.

As well as my method of using rainfall and temperature I also considered other methods. One was Russian research that states that the weather pattern in the winter will be the opposite to the weather on September 17th and November 7th. This autumn September 17th was N’ly and November 7th was NNW’ly. So, this would suggest a continental flow from S and SSE.

You can read the method of how I reached my conclusion here.

month ahead forecast, Monthly Review, monthly summary, Uncategorized

September 2016: very warm, very dry

October 1, 2016 wansteadmeteo 1 Comment

Last month was the second warmest September in a local record going back to 1797! The monthly mean finished 17.8C, 2.4C above average. Despite being an ‘autumn’ month September was actually a full degree warmer than June!

screen-shot-2016-10-01-at-11-55-19 — September 2016 was the second warmest in a local record back to 1797, though we’re talking by fewer than tenths of a degree.

The hottest September day since 1959 was recorded on the 13th when 33.1C was reached, the sixth equal hottest in the local daily record back to 1848.

The month also saw the warmest minimum recorded since 1959 when the mercury failed to fall below 18.7C on the 6th.

It was another very dry month, the third much drier than average month in a row: just 27.7mm fell, 24 per cent of average, making it the driest September since since 2007 and the 12th driest in the local record.

Like August, the month only falls down in terms of impressiveness when sunshine hours are considered. Some 119 hours were recorded, that’s 85 per cent of average, making it the dullest September for 15 years.

Air frosts: 0, Ground frosts: 0

So what has September got in store weatherwise? The models on the 1st suggest that a large Scandinavian high will become established to our NE bringing lots of settled weather and showers on coasts. There’s obviously the chance of trough disruption as the month progresses if the anticyclone’s influence declines.

Beyond the grasp of the models my usual long range outlook method falls down this month due to September’s warmth and dryness – there is nothing within +/- 10% of September’s statistics. I would guess, however, that we are looking at another drier than average month with frost becoming a risk as the month progresses where skies clear. There is also the chance of more pleasant autumn days where skies are clear during the day.

My September outlook for temperature was poor. I predicted a mean of 15.3C (outcome: 17.8C). It was much, much drier than I thought: 300mm (outcome: 27.7mm). Sunshine was poor: 140 hours (outcome: 119 hours).

Here follows the full weather diary for September…Full stats for the month here:http://1drv.ms/1rSfT7Y

1st: Sunny start but cloud gradually increased until it was overcast by 6pm. Clear spells overnight but warmer than previous nights.
2nd: Cloudy though some brighter intervals.
3rd: Sunny start, cloud began to pile in at 12.30pm with rain arriving at 5.30pm, this fell through the evening with some showers in the early hours.
4th: Bright, breezy start but rapidly turning cloudy and dull. Some rain overnight.
5th: Light rain and dull to start – this quickly clearing to cloud by 3pm. Things remained cloudy with a muggy night.
6th: Cloudy, dull and muggy start after warmest September night on record. Another warm night though muggy.
7th: Cloudy to 11am though sun breaking through as drier air arrived. Feeling humid.
8th: Sunny start but with plenty of cumulus, this quickly decreasing to leave clear sky.
9th: Cloudy morning though sky seemed to periodically clear of low cumulus before becoming overcast and very breezy in the afternoon. Some rain overnight and just before obs time.
10th: Cloudy start with patchy light rain, this briefly turning heavy at 1pm before turning occasionally moderate. Dreadful afternoon after recently. Clearing overnight to leave a sunny start.
11th: A glorious sunny day with only the odd patch of cirrus.
12th: Bright start with some sunshine, clouding over with a few splodges of rain with warm front. Then sunny and very warm.
13th: Sunny start with a few cirrus and castalanus around. Breezy at times with the thermals. The warmest September day since 1959 and 6th equal warmest since 1848.
14th: Sunny start with a few cirrus. A few patches of alto-cumulus later. Very warm but not as hot as yesterday. Warm, pleasant evening.
15th: Sunny with a few wispy cumulus, clearing to hot sunshine. Some alto-cumulus developed at 2pm and towering cumulus could be seen in distance. Thunderstorms reporting to NW of London. Cloudy and warm overnight with eight peals of thunder in the early hours and heavy rain.
16th: Light to moderate rain through the morning, petering out at 1.30pm.
17th: Cloudy, cool and breezy all day, at times dull.
18th: Cloudy all day, a bit warmer than the previous two days.
19th: Cloudy start though with sun breaking through briefly at 11am until 1pm then cloudy again. Rain at 1am that didn’t last long enough to register.
20th: Cloudy and fairly calm – a nothing day with odd very light drizzle.
21st: Bright start with cloud breaking to long spells of sunshine before more cloud moved in. Warmer than of late.
22nd: Cloudy but sun broke through giving pleasant afternoon and cool overnight.
23rd: Sunny, gin clear and cold start. Just a few fair weather cumulus through the day.
24th: Sunny start with cloud decreasing. Very warm in sun but cloud and breeze built through the day. Overnight light rain between 6am and 9am.
25th: Bright start after overnight light rain.
26th: Bright start with a few cloud breaks here and there. Heavy shower at 12.15pm with further threat of rain but stayed dry.
27th: Bright start with signs of a cold front moving in from south then cloudy.
28th: Sunny start with patchy cirrus, this tending to thicken at lunchtime to turn mostly overcast with humidity increasing. Breeze also picked up with reappearance of sun mid afternoon. Cloudy, very mild and breezy rest of the day.
29th: Cold front and brief heavy rain swept in at 10.03am. Then intermittent falls until 11.23am.
30th: Sunny, gin-clear start, patchy cumulus bubbling up at 10.30am. Cloud grew thicker around 12 noon with brief shower at 1pm. Then sunny spells and cloudier periods. Another shower just after nightfall then clear. Cloud moved in after 2am with another shower. Early sunshine gave way to moderate showers around 9.45am.

political weather, Rainfall, Seasonal summary, Summer 2016 forecast, Summer weather review, thunderstorm, Weather

Summer 2016 review

September 5, 2016 wansteadmeteo Leave a comment

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.

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.

With 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)

Forecast, month ahead forecast, Monthly Review, monthly summary, Rainfall, Weather

June 2016: extremely wet, dullest on record

July 1, 2016 wansteadmeteo 3 Comments

Storm clouds gathering was a common sight in June 2016, but enough about the tumultuous political situation…

lake — The levels of Heronry pond have benefited immensely from the rainfall which was 2.5 times the average in June

For anyone looking for summery weather there was little to cheer about. For sunshine the month was the dullest June in a record going back to 1797. Just 96 hrs were recorded – which is just over half what we can expect in an average June.

Most notable was the rainfall: just over 139mm fell which is 272 per cent of average, and the third wettest since 1797. Only 1903 and 1860 were wetter. The month also saw the record broken for highest daily rainfall in a 24-hour period. A multi-cell thunderstorm in the early hours of the 23rd saw 60.8mm fall, most of it in two hours, bringing flash floods to the surrounding area.

fax — The synoptic situation at midnight on June 23 when the heaviest rainfall this area has seen since at least 1960 fell

With the lack of sunshine and copious rainfall it is, perhaps, surprising that the mean temperature for the month finished just above average: 16.8C is 0.7C above the June average. The warmest day was the 10th with 25.3C recorded – only one other day saw the mercury exceed 25C – very unusual for this time of years.

Air frosts: 0, Ground frosts: 0

So what has July got in store weatherwise? The models on the 1st suggest more of the same weather that we have seen during the last third of June. Sunshine and showers with the occasional ridge possibly calming things down for a few hours.

blake — Roads in Wanstead were turned into rivers in the early hours of June 23rd

Beyond the grasp of the models my long range outlook method suggests a rather warm month at 50 per cent – so given the cool start perhaps we can look forward to something summery in the final half to one third? Rainfall and sun looks inconclusive so I would guess average. Because of the high rainfall last month I think my long range method falls down.

A slightly wetter than average month looks most likely at 50% probability. Sunshine probably about average.

So to sum up: mean 18.8C (0.3C above average), rainfall 50mm, sunshine 190 hours.

My June outlook for temperature was good. I predicted a mean of 16.9C (outcome: 16.8C). Rainfall was very poor: 38mm (outcome: 139mm). Sunshine very poor: 178 hours (outcome: 96 hours).

Here follows the full weather diary for May…Full stats for the month here:http://1drv.ms/1rSfT7Y

1st: Cloudy and cool all day.
2nd: Cloudy and cold all day, brief brightness at 11am.
3rd: Cloudy and cool all day, limited brightness late morning. Cloudy overnight with limited breaks – air was very humid with warm front and visibility severely limited.
4th: Cloudy all day though cloud was lighter and air felt warmer because of the warm front that came in yesterday from Europe. Brief milky sunshine at 7pm.
5th: Cloudy up until 9.30am when the cloud began to thin. Sunny spells from 11am before a clearance at 1pm interspersed with occasional cloud.
6th: A gloriously sunny day all the way through. A lovely evening too.

sunsetflats — Sunny sunsets were rare in June

7th: Sunny start but cloud rolled in at 1.30pm with thunder heard all around Wanstead. Some serious flash flooding in Croydon. Highest official total was over 40mm in Kenley. Just 1.7mm during the day but trough brought rain at 5am, about 3mm.
8th: Sunny start but felt very humid and oppressive. A thunderstorm skirted Wanstead at 1.40pm with thunder and much rain in Chigwell, not much in Wanstead. More thunder at 2.10pm. Rain came and went for rest of day until 7pm – very little upper air movement. Mostly cloudy overnight.
9th: Cloudy start but some sunny spells developing.
10th: Cloudy start but soon decreased with long sunny spells developing. Lower humidity so felt pleasant.

11th: Cloudy and humid start with very heavy rain at 3pm. This lasted for 45 minutes. More rain fell sporadically through the day, evening and overnight.
12th: Cloudy after moderate rain. Showers and longer bursts of rain returned before a brief clearance at 3pm. More showers piled in with a real corker to the north of Wanstead.
13th: Damp start soon led to light rain, turning persistant at 11am. Then outbreaks of rain throughout the day, evening and overnight.
14th: Light rain to start but this quickly gave way to heavy showers all day. Some brightness at 6pm then turning drier overnight. Gin clear dawn.
15th: Sunny start but with lots of convective cloud. Some drizzle but a heavy shower stayed to the east of Ilford.
16th: Bright start with sunny spells, more breeze than recent days
17th: Lots of cloud around though sunny spells arrived early afternoon. Then showers between 5 and 6pm.
18th: Cloudy with spots of drizzle. Feeling cold all day – a maximum of only 16.5C.
19th: Sunny start but cloud gradually increasing all afternoon. Rain by nightfall that fell intermittently for hours. Rain again at obs time.
20th: Rain to start that lasted, with variable intensity, through the morning. Sunny spells from mid afternoon.
21st: Sunny start with just a few cirrus and cumulus, this tending to increase through the morning to leave an overcast afternoon. Cloudy overnight – a few spots of drizzle on school run as frontal wave started to move across UK.
22nd: Cloudy start with warm sector drizzle. Showers developed at 11pm, much thunder and lightning and the rain turned really heavy through the early hours.

rainjune — Extremely heavy rainfall during the early hours of the 23rd

23rd: Cloudy and humid to 1pm. Showers at 3pm.
24th: Sunny with variable cloud. Feeling humid in the sunshine.
25th: Bright start with sunny intervals. Light shower at midday. Thunderstorms at 2pm, 4pm and 9.30pm.
26th: Sunny spells though significant cloud at times. Rain between 4 and 6pm.
27th: Mostly cloudy though with some brightness after noon. Warmest point was in the evening at 7pm.
28th: Bright though cloudy start. Some sunny intervals but rain late afternoon into the evening. Cool overnight.
29th: Cloudy and breezy, some rain in the air early afternoon and again in the early hours
30th: Cloudy with slight breeze. Some light rain in the early hours.

Environment, London pollution, Uncategorized

London’s choked by leaving the EU

June 30, 2016 wansteadmeteo Leave a comment

This month marks the 60th anniversary of the Clean Air Act, a piece of government legislation prompted in part by the Great Smog of December 1952 that caused between 4,000 and 12,000 premature deaths.

Air quality in the capital has vastly improved since those days of ‘pea souper’ fogs. A study of sunshine in Greenwich and other sites around east London reveals that winter months are, on average, around 18 per cent sunnier today than they were in the same period before the act was implemented in 1956. Though the cause of this is possibly partly because of a decline in winter anticyclones – weather systems that can give weeks of dull, murky conditions – further environmental legislation has helped.

Though the sky is clearer conditions at street level have grown steadily worse in recent years. During the first week of 2016 it was revealed that parts of the capital had already breached annual EU hourly limits for nitrogen dioxide – a pollutant that causes thousands of premature deaths through respiratory problems each year. A study last year showed that nearly 9,500 people die early each year in London because of long-term exposure to air pollution, more than twice as many as previously thought, according to the research.

Although action is being taken to reduce pollution from diesel buses, taxis and lorries the figures reveal that we are once again getting to the level of deaths caused by the Great Smog. The new mayor of London, Sadiq Khan, seems to be taking pollution a lot more seriously than his predecessor with a number of initiatives announced – making London compliant with EU legal limits well before the government’s target of 2025.

However, the mayor has also sent out conflicting messages by saying he backs the expansion of City Airport – you can’t have it both ways. And, if we do leave the EU, what will replace these EU legal limits?

With the current political situation lurching from one disaster to another I fear that the environment will get pushed well down the agenda. The current list of candidates vying to take over from David Cameron as prime minister include ‘dark horse’ Andrea Leadsom, the energy and climate change minister, who has been an ardent supporter of fracking. And on coal she recently sparked controversy in February where she assured the industry the pledged 2025 coal phase-out was just a consultation and encouraged it to suggest what ‘unabated coal’ means.

The many benefits of EU membership got lost in the debate over the last few weeks – improvement in the environment being one of them. It is why, without the beady eye of Brussels keeping watch over us, that we must ensure that the next government stick to their promise of continual improvement to the capital’s air quality.