What caused the heat wave?
The heat wave was triggered by the build-up of high pressures over Europe in recent days, which led to the movement of warm air northward from Europe over the UK.
“At this time of year, the winds from the south will always lead to above-average temperatures,” said University of Reading meteorologist Peter Inness.
“Air from continental Europe, the Mediterranean and even North Africa reaches the United Kingdom.”
“The passage to the east of the climate fronts and the low pressures of the North Atlantic are being blocked by high pressure on Europe,” added University of Reading climate scientist Len Shaffrey.
Was it related to the United States heat wave?
The recent warm weather in the US was caused by a high pressure dome that builds up over much of the country, trapping the summer heat.
This has more far-reaching effects.
“Heat wave conditions in the Midwestern United States and the East Coast have strengthened the jet stream,” explained environmental scientist Kate Sambrook of the University of Leeds.
‘The resulting thunderstorms that occurred on the mainland have helped the jet stream meander and move northward in the UK.
“As a result of this change, hot air has been drawn from Europe causing the high temperatures we are experiencing this week.”
The warm weather in the United States had been caused by a high-pressure dome that built up over much of the country, trapping the summer heat.
HOW LONG WILL THE HEAT LAST?
“Although there is some uncertainty in the forecast, it appears it will cool on Friday as high pressure on Europe slowly moves east,” said Dr. Shaffrey.
“This will allow climate fronts to move over the UK, bringing in cooler air and possibly some rain,” added Professor Shaffrey.
How hot will it get?
Meteorologists predict high temperatures on Thursday that will reach 38 ° C (100 ° F) over central and eastern England.
Although different forecasts anticipate slightly different details, “the general message of all forecasts is the same,” said Dr. Inness.
“It will be hot, high temperatures will persist throughout the night periods and there is a risk of thunderstorms in the UK.”
These will continue until Wednesday.
“If conditions continue, we can probably experience the hottest July on record,” said Dr. Sambrook.
“However, the result is uncertain as conditions are expected to change early next week.”
Oxford University climate scientist Karsten Haustein added that “there is a 40-50 percent chance that this is the warmest July on record.”
He noted that the final estimate depends on the observational data set being used.
While accepting that next week’s weather will determine this July’s place in the record books, Dr. Inness noted that 2019 brought us the warmest June known since 1880.
“In fact, 9 of the 10 warmest Junes on the world record have happened since 2000,” he said.
In Europe, he noted, this June was also the warmest on record, reaching nearly a degree Celsius above the previous number one in 2003.
“Weather records typically don’t break with such large margins, a few tenths of a degree would be more likely.”
Current conditions may be record high, but they are also part of a recent trend towards warmer summers in the UK.
‘2018 was the best joint moment [year] on record with the highest temperature measured around 35 ° C, similar to expected temperatures this week, “said University of Leeds climatologist Declan Finney.
The probability of experiencing such hot summers has increased from a probability of less than 10 percent in the 1980s to a probability of up to 25 percent today, he added.
IS CLIMATE CHANGE CAUSING HEAT WAVES?
“The fact that so many recent years have had very high summer temperatures both globally and across Europe is in line with what we expect from man-made global warming,” said Dr. Inness.
“Changes in the intensity and probability of extreme weather is how climate change manifests itself,” said environmental scientist Friederike Otto of the University of Oxford.
“That doesn’t mean that every extreme event is more intense because of that, but many are.” For example, each heat wave that occurs in Europe today is made more likely and more intense by human-induced climate change. ”
However, local factors also play an important role, as each extreme weather event is influenced by location, season, intensity, and duration.
Experts point out that the current heat wave is not the only notable indicator of climate change, and that ongoing droughts, such as those experienced in many parts of Germany, are also in line with scientific predictions.
Research on the 2003 European heat wave at the time suggested that human activity had more than doubled the risk of such hot summers, and that annual heat waves like the ones we are experiencing now could become common by the middle of the century.
“It has been estimated that around 35,000 people died as a result of the European heat wave in 2003, so this is not a trivial issue,” said Dr. Inness.
“With more climate change, there could be a 50% chance of having hot summers in the future,” agreed Dr. Finney.
“It is similar to saying that a normal summer in the future will be as hot as our hottest summers to date,” he added.
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