UK Weather - Summer 2015

[Simon Culling]

Summer begins today (meteorologically speaking) on Monday 1st June but you would not know it judging from the weather. We have another major low coming our way and it is expected to cross northern Scotland during today and overnight into Tuesday with the central pressure predicted to be near 970mb which is low for this time of year. It will bring more wet and windy and cool weather and it will be followed by a cold westerly flow. However, a ridge of high pressure building from the south west from Wednesday onwards promises a break (probably temporarily) in this run of depressions (and the attendant cold north westerly flow) for a while with some drier and warmer weather for a few days into the weekend. The earlier expectations of a UK heatwave and thundery breakdown have been shunted eastwards by the models as has been the norm in recent years, so France and the Benelux countries might see the action instead.

[Simon Culling]

The low crossed northern Scotland overnight Mon/Tues at around 973mb and brought strong winds for the time of year particularly to Eire and the Irish Sea with gusts to 60-75mph recorded. As the low moved away on Tuesday (2nd June) the strong winds transferred across Wales and England making it a very blowy day for the time of the year. The strongest winds were on the Welsh coasts and in a swathe across the Midlands to East Anglia with gusts up to 65mph recorded. A late season 'Fen Blow' occurred again in parts of Cambridgeshire and Norfolk. Here in Milton Keynes we had a breezy and damp night and morning, but as the sun came out on Tuesday afternoon the breeze really picked up and became a strong wind in the afternoon with local stations recording wind gusts up to 55mph. As the trees are now in full leaf they were performing a merry dance and there is quite a lot of twig and small branch debris on the ground with a few trees down.

It is calmer this morning and we are now looking at a few dry and sunny days with a 'mini-heatwave' on Friday when we might see 25-27*C in the SE of England. There is some moisture suggested in the models so there is the chance of a few storms sparking off as well.

The first day of June (Monday) was also a chilly one with sub 10*C maximums in parts of the west. The lowest I could find were 8.1*C at Lake Vrynwy (Wales), 8.9*C at Killylane (Co Antrim) and 9.4*C at Pennerley (Staffs).

[Simon Culling]

We have had our first 'Spanish Plume' event of the summer overnight Thurs/Fri 4th/5th June with quite a few elevated thunderstorms breaking out in a line north east from the Sussex coast through London and into East Anglia. The plume destabilised in the early hours and set off some quite electrically active high base storms with some hail reported. Thursday was not particularly warm with the highest temperature recorded being only 23.8*C at RAF Northolt in NW London. A few more storms may form later this morning in the far east of England as temperatures reach 25-26*C but a cold front is now approaching from the west so it will be cooler over the weekend.

EDIT: The highest temperatures reached on 5th June (Friday) were 26.7*C at Ftrittenden (Kent), 26.1*C at Gravesend (also Kent) and 26.0*C at Shoeburyness (Essex).

[Simon Culling]

The storms overnight into Friday morning did not produce big rainfall totals and the highest I could find was 12mm at Wainfleet in Lincolnshire. However, they were electrically active and produced hailstones up to the size of 50p pieces (about 30mm diameter) in and around Tunbridge Wells in Kent.

http://www.independent.co.uk/news/uk/ho ... 00541.html

Despite the plume of warmth on Thursday + Friday the month of June has got off to a cool start and whilst it has been sunny on both days of this weekend, the temperatures have been much lower (between 15-20*C). The week ahead looks fine and settled to start with, but more unsettled with more rain towards the end of the week.

The CET for June up to the 6th was 12.8*C (-0.4*C) and the EWR up to the 5th was 12mm which is 18% of the monthly average of 65mm.

[cantygal]

Always enjoy your comments Simon.

I see last week the cricket test at Headingly, Leeds was played under cold and blustery conditions.

The NZ cricket captain called it an 'Invercargill wind' which suggests it was bitterly cold.
I understand the thermometer never rose above 12 degrees across 5 days which makes it the bottom three cricket tests in terms of cold of all time if that is the case.The added windchill made it apparently feel like 6 or 7 degrees for much of the game.
Can you confirm this at all please?

[Simon Culling]

Hello cantygirl, I will attempt to answer your question in the spring weather thread as most of this game fell into this season.

It has remained cool and breezy since the weekend with a big high pressure (1040mb) taking up residence just to the west of the UK and this has been feeding in north or north easterly winds. It has been cool especially at night with a local air frost in prone areas on the last two mornings. The lowest temperatures were -1.5*C at Katesbridge (N Ireland) on the 9th and -1.0*C at Lanwnnen (nr Lampeter, W Wales) on the 8th.

The CET for June up to the 8th was 12.5*C (-0.9*C) and the EWR, also up to the 8th, was still 12mm.

It looks like a couple more fine days before it turns warmer and wetter from Friday with the chance of some home grown thunderstorms.

[Simon Culling]

It was quite warm at the end of last week and the highest temperature of the year so far (26.8*C) was recorded on Friday at Kew Gardens, London. Some thunderstorms tracked north from France in the evening and a few home grown elevated storms also developed but many places missed them, but a general area of rain formed overnight into Saturday and stuck over Wales, Eastern England and the Midlands during Saturday giving many places 20-30mm of rain and up to 50-55mm to the counties of Nottinghamshire and Leicestershire. It was also 10*C cooler in many places on Saturday (13th June) and the next day was also cool and cloudy.

A ridge of high pressure has extended north east from the Azores high and this looks like giving much of the UK a few fine, dry and warmer days, but there are suggestions of a return to a more north westerly flow again by the end of the week which means cool and showery weather just in time for the weekend!

[Simon Culling]

It has been a bit warmer for the last couple of days (21-23*C here in Milton Keynes) but a weak cold front will introduce cooler weather for tomorrow and into the weekend. It should be dry until Saturday when some showers are expected. Beyond that, we are still looking to the north west for our weather so it is unlikely to warm up.

The CET for June was 13.0*C (-0.8*C) up to the 16th and the EWR was 24mm up to the 15th, which is 37% of the monthly average.

[Simon Culling]

The weather has been rather non-descript in the last week or so with average temperatures and not too much in the way of rain. We had quite a few thunderstorms over England on Saturday (20th June) in a slack westerly flow and we heard thunder here in Milton Keynes for only the second day this year. Otherwise it has been generally dry in the south of the UK with some sunshine. Looking forward I can only see more of the same, although a notable heatwave will build over Spain and southern France at the weekend and we may catch the edge of this (and a few storms) early next week as the plume moves north eastwards into central Europe.

The CET was 13.5*C (-0.5*C) up to the 23rd and the EWR was just 34mm up to the 22nd, which is 52% of the monthly average.

[Simon Culling]

There have been some notable variations in the weather over the country in the last few days with the south generally getting the 'better' weather. For example on Wednesday (24th June) it was fine in the south with sunny periods and a max of 24-25*C in the London area, but cloudy with a little rain in Scotland with maximum temperatures of just 9.3*C at Craibstone and 9.8*C at Dyce Airport, both in the Aberdeen area. The south was in a weak continental flow whilst Scotland remained to the north of the front (and in the Atlantic air) pushing up from the south.

The 5-7 day forecast has changed considerably in the last day or so with the very hot air developing over southern Europe now expected to move north to the UK from the middle of next week. There are some suggestions of the mercury reaching 32-33*C in the south for Thurs and Fri next week with enough juice in the atmosphere for a few storms. Whilst confidence is now quite high for the warm temperatures, I think guessing at the storm potential at that range is a bit brave.

EDIT: Today (Fri 26th June) was the warmest day of the year so far in the UK with maximums of 27.8*C at Gravesend and 27.7*C at both Writtle (Essex) and London Heathrow.

[Simon Culling]

The plume of hot air moving north from Iberia has begun to impact the UK with our first 30*C+ day today, Tuesday 30th June. The forecast thickness values for tomorrow are around 565dm over SE England so we will see quite a hot day - some forecasts range as high as 34-35*C in the London area. The highest temperatures today were in and around London and to the NW into the Midlands as the wind was from the SE. Highs were:

30.5*C at Northolt (NW London)
30.4*C at Kew Gardens
30.3*C at London Heathrow
29.9*C at Pershore (Worcestershire)
29.4*C at Brize Norton (Oxon) + Coleshill (nr Birmingham)

The mercury reached 33.0*C at the Maison St Louis Observatory (in St Helier) on Jersey in the Channel Islands which is close to northern France where temperatures got close to 40*C today.

A few medium level storms have recently (8pm) broken out over the English Channel and will affect the south coast, but tomorrow there will be a lot more low level moisture over the UK and we could see some big storms over the Midlands and northern England.

[spwill]

I see London has a forecast high of 33C today, certainly a hot day ahead given the humid air mass across the region.

[NZstorm]

The plume of hot air moving north from Iberia has begun to impact the UK

A few medium level storms have recently (8pm) broken out over the English Channel and will affect the south coast, but tomorrow there will be a lot more low level moisture over the UK and we could see some big storms over the Midlands and northern England.

The layer of warm air is also known as the EML elevated mixed layer. I see the lapse rates over UK today will be 7C+ which is very unstable given warm surface air. Maybe lots of capping though.

An EML is a primary factor behind the USA tornado/severe storm season. The EML comes up from Mexico.

[David]

I see It reached 36.7 degrees at Heathrow airport, London on Wednesday. That's hot!

[NZstorm]

I see there was a huge eletrical storm over North England last night.

[Orion]

Quite a thunderstorm in Newcastle:
http://www.chroniclelive.co.uk/news/loc ... st-9548511

[Simon Culling]

It was indeed hot in the south east of the UK on Wednesday 1st July with provisionally the highest ever United Kingdom temperature recorded for the month of July. The heat was restricted to the south east and up into the midlands and the southern parts of north east England and was shunted away to the east overnight into Thursday morning. The highest temperatures recorded at Met Office sites were:

36.7*C at London Heathrow
35.7*C at Northolt + Kew Gardens
35.3*C at RAF Wittering (Cambridgeshire)
34.7*C at Gravesend
34.1*C at Charlwood (Surrey).

The storms were triggered later in the evening mostly over northern England where it had ironically been much cooler at the surface, with golf ball sized hail causing damage in Lancashire and more notably in Yorkshire and Durham counties. I will dig out some more information on this when I get more time.

[NZstorm]

The storms were triggered later in the evening mostly over northern England where it had ironically been much cooler at the surface, with golf ball sized hail causing damage in Lancashire and more notably in Yorkshire and Durham counties. I will dig out some more information on this when I get more time.

The storms will have been elevated and that golf ball hail an elevated supercell!

[Skywatcher]

And some impressive lightning over eastern Scotland: http://www.bbc.com/news/uk-scotland-33359707#1

[Simon Culling]

A couple of significant storms developed in the early evening of Wednesday 1st July, one just to the north of Manchester and the stronger of the two initiated in Yorkshire moving northeast through County Durham and the Newcastle area. Both storms produced golf ball sized hail (many pictures on Facebook) but the latter storm appears to have produced stones a little larger than this. A great video has been posted from Swaledale of the hail falling (although not the biggest stones) and the swirling fog forming after the storm in the rapidly cooled air. The damage of the roof tiles and the holes in the lawn (at about 2:40) suggest stones bigger than the quoted golf ball size.

https://www.youtube.com/watch?v=LRT-u3pMAes

[Simon Culling]

After another humid and warm day on Friday 3rd July (max temperature 28.3*C at Hampton Water Works, London) a north moving warm front triggered a whole clutch of elevated storms over southern England later in the evening and these moved north affecting much of the rest of England overnight. They produced many reports of frequent lightning and sharp showers with quite big hail reported again, this time in Dorset - possibly up to walnut size. Many observers claim that these were the best lightning displays for many years and here in Milton Keynes we had a couple of hours of frequent lightning, but mostly in the clouds in this area - but I did witness a couple of very close ground strikes to my SW with rapid shot-gun thunder to follow.

I have attached a copy of the recorded lightning strikes overnight 3/4 July which I have copied from another forum (UKww). I'm sure they wont mind.

[Richard]

Thats impressive Simon

[NZstorm]

Wow, good lightning count. The London ukmet sounding indicates an elevated MCS.

[Orion]

Lightning caused fatalities in Wales:
http://www.bbc.com/news/uk-wales-mid-wales-33401965

[Simon Culling]

Richard, NZstorm - I have seen various lightning strike counts for England for the overnight period Fri/Sat and they range between 93,000 and 110,000. Most observers commented on the frequency of the lightning and its brightness. This was like the night storms we used to get more often 10 years ago.

Orion, thanks for posting the link to the two lightning strikes in Wales. This is a very tragic event and highlights the danger of being on a mountain side during a thunderstorm - there is nowhere to hide. Yesterday, Sunday 5th July was showery over most of the UK with thunderstorms and hail reported in quite a few places, but these were of the half a dozen bangs and then gone variety.

The final CET for June was 14.0*C (-0.2*C) making it the second colder than average month in a row. The EWR was 39mm which is just 59% of the monthly average.

July has started on a warm note with the CET up to the 4th being 19.8*C (+4.4*C) and the EWR 12mm also up to the 4th which is 19% of the monthly average of 62mm.