SUMMER SO FAR & Europe August 2021 Outlook

Written by on July 29, 2021 in Rest of Europe, United Kingdom & Ireland with 0 Comments

For Northwest Europe (Ireland, UK, France, Low Countries), it’s been a summer of mixed fortunes with spells of wet, dry, cool and warm with of course the relatively long lived warm to hot spell which during mid July.

An unusual back to back flash flood event struck London ahead and after a pretty average 7-day ‘summer heat wave’ thanks to strong instability embedded within a warm, humid air mass. By average I mean the core of heat was to the west of the capital and highs 29-32C for a few days is what you would expect every year in London and SE England.

For Northern and Northeast Europe, incorporating much of Scandinavia, the Baltic states and western Russia, it’s been a very dry, very warm summer thus far.

In terms of average, Germany, Switzerland, Austria and through the Mediterranean countries, it’s been a similar kind of summer to that of Northwest Europe with mixed fortunes of relative cool coupled with periods of hot to record hot conditions, especially through Italy, Greece and the islands. Extreme rain events of historic levels have of course hit Germany, Belgium and Switzerland hard.

Spain and Portugal too have seen a very mixed summer with below average temperatures and above average rainfall for most of Iberia except along the Med coast.

Despite the recent but quite typical mid-summer hot spell, France is average temperature-wise with well above average rainfall. 2021 will likely be one of it’s coolest, wettest summers in many years. Like in June, several July days have featured persistent rainy weather combined with unusually cool temperatures.

For the UK and Ireland, the July 13-24 period proved far warmer and for longer than I had forecast. I had forecasted a pretty mixed June and quite disappointing July in my full summer forecast. In the nearer term July Outlook, I had a mixed month with a week-long period of warm and sunny weather. That, was underdone in my part but a book end month of very unsettled opening 10 days and closing 7 days has turned out not bad.

The core of heat was in the slightly more unusual area covering much of Ireland, Northern Ireland, SW England, South Wales and west Midlands where the Met Office issued their first ever amber extreme heat warning due to day after day of upper 20s/low 30s and nights near 20C in an area unaccustomed to such persistent heat.

Met Office

NORTHERN IRELAND SET’S NEW ALL-TIME HEAT RECORD 3 TIMES WITHIN 1 WEEK

First came Ballywatticock, Co Down (near Newtonards) where the thermometer reached 31.2C, surpassing NI’s previous all-time record of 30.8C recorded twice, first in 1976 then 1983.

Met Office

A few days after Ballywatticock hit a new national high, Castlederg, Co Tyrone overtook by topping 31.3C only to be overtaken the following day by Armagh when they hit 31.4C.

Met Office

500mb geopotential height anomaly for summer 2021 to date!

Summer so far

Like we had with the spring, this summer’s upper air pattern has been dominated by an incredibly persistent high latitude/Scandinavian block with twin cut offs trapped beneath, keeping it cool, wet in both SW and SE Europe.

This anomalous setup explains with relentless warmth across the north and cool further south and why we saw the big storms and record flooding over central areas, especially Belgium, Germany and Switzerland as well as even London. Is this a by product of the low solar?

2 metre temperature anomaly

June 2021

Credit: Michael Ventrice

July to date

Credit: Michael Ventrice

June ended and July began with low pressure over France and high pressure over Scotland, this brought an unsettled England, Wales, Low Countries and France, drier, sunnier and warmer Northern Ireland, Scotland and Scandinavia.

We end July unsettled once again but in a more widespread fashion. All in all it’s been a bookend month.

FORECAST vs REALITY?

June 2021

What was said…

First 10 days would be largely warm and dry but a decrease in pressure mid month on. Cooler, wetter 2nd half to the month featuring some unusually cool days and nights.

What happened…

Indeed the first 10 days did turn out warm and dry for much of the UK with peak temperatures reaching 29C. It was the first meteorological summer month in the UK to not reach 30C since August 2017. From mid month on it indeed turned fresher and wetter. We also observed the coolest June night for the UK since 2012 and some very cold days around the solstice.

Overall, June turned out not too bad with the warmer than normal month featuring unusually cool June days and nights but it was wetter than anticipated.

SCORE: 7 OUT OF 10

July 2021

What was said…

LONG TERM IDEA: Like, last year, a disappointing July to come with any brief spells of warm and sunny. Could feature first none 30C for UK since 2011.

MONTHLY OUTLOOK: Cool, unsettled opening 7-10 days. About a week long warm to hot spell mid-month followed by cool, unsettled final 10 days.

What happened…

When looking at the long term idea. It was a poor projection, albeit it’s pretty much guess work when talking beyond 1 month out. The hot spell was longer (more than a week) and stronger (above 30C and widely) than expected BUT July too has been quite changable and my monthly outlook, though not perfect, did have merit with unsettled and cool opening 10 days and now closing 7 or so days.

SCORE: 5-10

COMMENTS

FOR SUMMER 2021 AS A WHOLE, THERE ARE PLENTY OF ASPECTS WHICH WERE QUITE OUT IN MY OPINION BUT THERE WERE ASPECTS PROJECTED WELL INCLUDING THE PERIODS OF COOL AND WET WHERE LOW PRESSURE DOMINATED, IE, LOW HEIGHTS FORECASTED FOR JUNE NEARER FRANCE, ABOVE NORMAL OVER SCOTLAND EXTENDING THROUGH SCANDINAVIA. UNUSUALLY COOL DAYS AND NIGHTS IN JUNE WAS A GOOD CALL.

JULY WAS POORER BUT STILL FEATURED UNSETTLED WHICH MAKES IT BY FAR NOT THE WORST FORECAST. KEEP IN MIND THE FURTHER INTO SUMMER YOU GO, THE FURTHER INTO THE FUTURE YOUR PROJECTING AND ACCURACY RATE IS GREATLY REDUCED.

I’M PLEASED AT WHAT I’M SEEING FOR AUGUST AGAINST MY PROJECTIONS. A WET, COOL AUGUST WOULD PUSH MY OVERALL SUMMER FORECAST IN LINE WITH A 6 POSSIBLY 7 OUT OF 10.

How’s our final month of summer looking?

As we move into August, high pressure shall be replaced by low pressure and this looks to become widespread throughout the western and northern flank of Europe. Once again, the heat focuses on the eastern side of the continent.

My long term thinking (since May) of a cool, unsettled August looks to have merit according to the CFSv2 as well as GFS ensemble. Cool and unsettled looks to be the theme through at least mid-month for France, UK/Ireland, Low Countries and Scandinavia as as stated in my long range forecast, August should be the coolest summer month this year. That wouldn’t be hard to achieve given the warmer than normal June and July for the UK and much of Europe.

CFSv2 weeklies

500mb height anomaly

week 1

Credit: Tropical Tidbits

week 2

Credit: Tropical Tidbits

week 3

Credit: Tropical Tidbits

Precipitation anomaly

week 1

Credit: Tropical Tidbits

week 2

Credit: Tropical Tidbits

week 3

Credit: Tropical Tidbits

Temperature anomaly

Credit: Tropical Tidbits

Credit: Tropical Tidbits

Credit: Tropical Tidbits

According to the CFSv2 for the month as a whole, well it’s quite different to the month that’s drawing to a close that’s for sure and fits nicely with my end game to summer 2021.

CFSv2 for AUGUST

500mb height anomaly

Credit: Tropical Tidbits

Precipitation anomaly

Credit: Tropical Tidbits

Temperature anomaly

Credit: Tropical Tidbits

FEATURED IMAGE CREDIT: LDN From the Rooftops

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