The wider impacts of European heat: UK sunshine, Alpine glaciers, and Scottish snow patches

The current spell of hot weather

The current spell of hot and sunny weather is proving to be more similar to the August 2022 heatwave than the July 2022 heatwave that saw 40C recorded in England for the first time since instrumental records began several centuries ago. The emphasis has been on a relatively prolonged spell of hot and sunny weather for most of the country and relatively unexceptional daytime temperatures, rather than a record breaking heat spike. However, temperatures have still been hot by most standards, with the highest temperature so far being 34.7C at Astwood Bank, near Birmingham, on 11 July. 

Due to the recent hot weather, temperatures are currently running substantially above the long-term average for July in most parts of the country. According to Starlings Roost Weather, the first 11 days of July have been notably sunny from the English Midlands southwards, with a number of sites having already exceeded 100 hours of sunshine, including sites near Exeter and Southampton, while most of Wales is on 80-90 hours. Sunshine has been nearer normal in northern England and the east of Scotland. However, much of Northern Ireland and north-west Scotland have been very dull so far, with less than 40 hours of sunshine at some spots in north-west Scotland, illustrating that once again there has been an enhanced northwest-southeast split. 

A more changeable weather regime is coming starting early next week, but with no guarantees of much rain in the south and especially south-east of England

The hot and sunny weather will break down from the west early next week, and then it looks probable that we will move into a period of more changeable weather, with much of the country seeing some rain and showers at times, including some eastern counties that have recently been very dry for a while - parts of eastern Scotland, north-east England and the east Midlands. The jet stream will be heading further south than we have seen for a while, so low pressure systems will be tracking further south and may sometimes track over parts of the British Isles. Until recently the ECMWF 42-day forecast model had been suggesting that high pressure could dominate these parts for up to a few weeks, but it has backed away from this considerably and now suggests that generally unsettled weather could continue for much of the rest of July.

However, many forecast model runs are indicating that it will probably remain mostly dry in the south and south-east of England during the coming week, despite the shift to a more low pressure dominated regime. While there is potential for substantial rain to affect those southern counties starting in around 10 days’ time, this is a long way off and subject to change. 

In addition, it looks probable that southerly and south-westerly winds will blow frequently during the next ten days or so, so although it will become more changeable for most of the UK, it will remain generally warmer than average for the time of year, not as hot as recent days, but with potential for brief hot spells especially in the south and east of England when we pick up air masses from France and Spain. Current forecasts suggest that it will often be hot in the southern half of Europe during the coming week or two, which means that if we pick up southerlies bringing in air masses from that region, it probably won’t take much for it to get very hot again.

Melting European glaciers and a lack of Scottish snow patches

The recent hot weather over central and western Europe has been causing considerable melting of the glaciers in the Alps and Pyrenees, with reports of the 0C isotherm having exceeded the 5000m level at times. This has been a recurring theme in many recent summers, with recurring “heat domes” over central and western Europe accelerating the retreat of the glaciers. I recall this first being widely noted in the summer of 2003, when there was the prolonged heatwave over much of France during the first fortnight of August when temperatures widely reached 35-40C by day. 

Meanwhile, Scottish snow patches are currently unusually few and small at present, due to the warm spring and early summer as well as a lack of substantial snowfall during the winter months.