Monthly Weather Summary September 2020

Here’s what happened in September 2020.

After a wet day on the 2nd, September weather was quite decent until the 22nd. There was a short heatwave in mid-month when the temperature hit a lovely 26.6 degC. Towards the end of the month the weather turned very Autumnal indeed. Temps plummeted after the deluge on 23rd, and the maximum temperature on 24th was only 10.2 degC. Quite cold for September. In fact I’m told it was one of (bottom 20) the coldest September days since 1900.

This cold spell was due to a depression in the Southern North Sea dragging in North to North Easterly winds from the sea on the North side of the storm. Some wild seas were observed in coastal towns such as Seaham.

The cold spell dragged down the overall monthly mean, which had been running a degree or so above average until then, and it finished at 13.2 degC, which is almost bang on average.

The absolute minimum of 3.9degC was recorded on the morning of the 28th, as winds dropped behind the depression in the cooler northerly influenced airstream.

Durham Weather Summary 1st-17th September 2020

Durham Weather Summary 18th-30th September 2020

September 2020 Air Temperature Summary at Durham

Rainfall

The total for the month finished around the long term average, but about half of that total came on the 23rd. The daily total of 28.5mm wasn’t exceptional for September, but was in fact the 5th fall of 20mm or more in the calendar year so far. Are these high rainfall total days getting more frequent? They certainly seem to be.

The total rain days of 16 was quite low for Autumn, although when anticyclonic weather dominates it can happen.

September 2020 Rainfall Summary at Durham

Atmospheric Pressure

The most was identified as strongly anticyclonic, and the few cyclonic days were centred around the strong depression that hit around 23rd-25th. There were some very strong gusty winds around the low, which seemed to peak around 25th.

September 2020 Atmospheric Pressure Summary at DurhaM

Durham Weather Summary chart September 2020

Misty morning over Durham Cathedral 24th September 2020
Misty morning over Durham Cathedral 24th September 2020. Photo courtesy of Paul Cleasby.

September 2019 was mostly dry, but still wet!

The headline says it all. September 2019 was really dry and quite pleasant for the first three weeks before the rains came back.  Only 8.1mm fell in the first three weeks, as pressure remained high. Remarkable that the total for the month ended up at 81.0mm, making it a ‘wet’ month overall. That just shows how monthly statistics can completely mask what lies within.

Temperature was very equable, with no really warm days, but no really cold ones either. The warmest temperature came in a short 3 day spell grouped around 20th, when 21.9 degC was reached. The coldest was the morning of the 8th when temps dropped to 3.5 degC.

September’s overall mean temp (mean max+mean min/2) was 12.8 degC, which is slightly below the 1981-2010 mean. This has been rare in recent times.

 

Monthly Report – September 2018

A very average September temperature wise, there were some warm days at the start of the month and another on 26th.

Rainfall total was slightly above average, mainly due the extremely wet 2 day period of the 20th and 21st. The total for these 2 days was 44.6mm, which contributed more than half of the final total for the month.

High pressure then dominated until the end of the month, with some chilly nights in the last 10 days.

Daily Weather summary Durham 1st-17th September 2018
Daily Weather summary Durham 18th-30th September 2018
Monthly summary of temperature at Durham September 2018
Monthly summary of Rainfall at Durham September 2018
Monthly summary of Air Pressure at Durham September 2018

The River Floods Again – September 2012

The very wet Summer of 2012 continued into Autumn. The river burst it’s banks again in the city. This red car (Ford Ka) became quite famous as it bobbed about in front of the new Radisson Hotel (due to open a couple of months after this photo was taken).

A view of the flood from the Passport Office/National Savings Building. The red car can just be seen in the left mid-distance.

Rising water levels in the River Wear at Durham Credit: ITV Tyne Tees

The Figures

There was exceptionally heavy rainfall and flooding towards the end of the month. The rainfall was spread across two days, with 47.4mm recorded on the 24th and 40.8mm on the 25th. The former is the 27th wettest day on record at Durham since 1850 and the latter was the 41st wettest. Looking at 2-day totals, the combined total of 88.2mm is the 5th highest 2-day total since 1850, although well less than the record holder, 10th / 11th September 1976 when a total of 120.1mm was recorded. The heaviest rain fell late on the evening of the 24th when 16mm fell in 3 hours. It was the wettest September since 1976 and the 7th wettest on record.

http://community.dur.ac.uk/durham.weather/weather-data-2011-2015/the-weather-at-durham-in-2012/september-2012/

Professor Tim Burt
Department of Geography
Durham University

River Wear in flood again, Sepember 2008

The River Wear in spate again in mid September 2008. The main wear, normally visible about 4ft above the river is almost totally submerged. The river was 6” away from bursting it’s banks.

This was the scene in Croxdale in September 2008 as firemen begin the cleanup process after another flooding episode at The Honest Lawyer Hotel. The River Browney burst it’s banks and inundaded the hotel and motel rooms.

 

Further North in Northumberland, there was a disastrous flood in Morpeth on 6th September.

The centre of low pressure was slow-moving over Cent England on the 6th. There were continuing heavy falls of rain overnight across N England, with much of England, Wales and S Scotland seeing rainfall.

Rainfall on September 5th: Morpeth Cockle Park 80.7mm; Chillingham Barns 76.2; Westgate-in-Weardale 72.6; Stanhope 69.3; Copley 56.5; Whitley Bay 36.5; September 6th; Chillingham Barns 82.1; Westgate-in-Weardale 47.6; Spittal 29.1; Whitley Bay 26.7

Met Office : Heavy Rainfall Early September 2008

The Morpeth flood: 6 September 2008

The North East region, despite its general rain-shadow setting, is no stranger to floods (Archer, 1992) and Morpeth has endured severe flooding often: for example, in 1863, 1876, 1877, 1878, 1881, 1886, 1898, 1900, 1903, 1924 and 1963.

The event of 6 September 2008 was in many ways typical, and has been well-documented. The floods on this occa- sion were brought about by 24 hours of persistent rain causing the River Wansbeck to burst its banks, flooding the town (Figure 4) and causing damage estimated as costing £40 million.

The cause was in contrast to that of the previous serious flood, on 7 March 1963, which was due to the thawing of deep snow that had accumulated over the famously-cold preceding winter. The 2008 event was associated with a slow-moving but active frontal system. In this case the centre of low pressure lay to the south of the region exposing it to easterly winds, turning this normally sheltered side of the country into an exposed region and producing an estimated 80mm or more of rain in the pre- ceding 24 hours over the catchment. The distribution of precipitation over Britain on the evening of 5 September is illustrated in Figure 5: the control exerted by the slow-moving fronts across northern England is clearly seen.

An important causative agent was that the preceding summer had been wet, the Northumbrian region having experienced 200% of average rainfall in July and August, so that soil-moisture deficits were very low. The catchment consists of narrow, relatively steep-sided valleys, encouraging the rapid movement of water into the tributary channels upstream of the town; the Environment Agency estimated that as much as 54% of the rainwater took the form of this runoff. But these rains were widespread and many gauging sites in northern England recorded new record peak flows (Environment Agency, 2009) and it was the combination of the factors noted that brought about this disaster.

There was an almost identical repeat of these conditions in the town (whose motto, with an irony not lost on local residents, isInter Sylvas et Flumina Habitans or living between woods and waters) on 25 September 2012.

From “Regional weather and climates of the British Isles – Part 4: North East England and Yorkshire” by Dennis Wheeler, University of Sunderland, Weather July 2013.

September 2006 – Warmest September on record

September 2006
Another one for the record books, September 2006 is the warmest September on record, beating September 1729 in the CET series. This record had stood for 277 years up to this year, and was the longest running record of any ‘warmest month’. Recently broken ‘warmest’ records are seemingly gathered in the second half of the year, with the longest standing remaining record for July-December resting with December 1974 (this was broken quite decisively in December 2015). The absolute high for September was raised to 27.1 degC on 21st of September 2006. There were no cold nights, and rainfall was slightly above average.

Again, I use my record from Ferryhill to show the daily conditions.

Durham Cathedral Sunset September 2005

durhamcathedralsunset

This was one of my favourite weather photos from Durham City. It was taken on the way up the steps into the Durham University Students Union building (Dunelm House) in New Elvet. The sun was going down behind Durham Cathedral.

That was the last I saw of the sun that night as I disappeared into The Durham Beer Festival being held at Dunelm House.

Electrical Storms in Northern England – 11th September 2000

Amazing Storms Cause Havoc

Here is what I wrote in my weather diary on the night:

There have been quite severe electrical storms in the North East of England tonight with torrential rain at times. In Ferryhill, the storms started at about 2030 GMT after the weather became very muggy and humid at the end of the afternoon. Late afternoon Dew Point was 19 degC with RH at 92 %. Between 2100 GMT and 2315 GMT lightning flickered almost constantly in all quadrants of the sky, mainly cloud-cloud at first but then some hefty cloud-ground discharges later.

I rang a friend of mine on his mobile to see if he was watching the spectacle. When he answered, he said he was sitting in his car in Aycliffe Village. He said the rain was torrential and we observed the same lightning discharges from about 7 miles apart. While we were talking, a lightning bolt came to earth about 200 yards from where he was sitting and struck a tree on the village green. He described the lightning engulfing the canopy of the tree with a ‘blue electric shroud’. The tree didn’t split, but the ground around the base was seen to be steaming after the strike.

Two miles up the road is the Plastics Factory where we work on Aycliffe Industrial Estate. He said he could hear the site Emergency Alarm going off and it sounded for 50 minutes. Shortly after this 5 or 6 Fire Engines roared through the village from Durham on the way to the factory. The site emergency alarm had obviously been set off by a strike. It’s unknown at the moment if any damage has been caused as they disable all public phone lines into the site when the emergency procedure is triggered. I’m dreading turning up tomorrow to see the effect this has had on our site computer network.

I’ve seen all colours in the lightning discharges tonight from yellow, through orange to green and purple. There seemed to be some circulation involved with rain coming with a slight southerly drift, then ten minutes later from the north, then back to the south again.

Rainfall at it’s heaviest here at Ferryhill yielded 6.8 mm in 30 minutes between 2100 and 2130 GMT but reported to be heavier in Aycliffe. My next door neighbour finishing his 2-10 shift had to stop on the A167 on the way back as a nearby strike blinded him temporarily and took the streetlights out at the same time, plunging him into total darkness before the next lightning lit his way.

The lights are flickering again, so i’m going to post this before I need to disconnect the modem again for the night !