Potentially Historic Early-Summer Heat Wave To Roast Europe

An intense heat wave is set to bake Europe in the coming days, and it could be historic, potentially shattering records across a large portion of the continent.

The heat wave is expected to peak in the middle part of this week when a swath from Spain to Poland is expected to see temperatures at least 20 to 30 degrees (11 to 17 degrees Celsius) above normal. Actual temperatures should surge to at least 95 to 105 degrees (35 to 40 degrees Celsius) over a sprawling area, with some spots hotter.

Weather Underground's Bob Henson notes that this projected heat wave is "unusually strong for so early in the summer."

Early summer heat waves can be especially lethal, as people have not yet had time to acclimatize to the higher temperatures. Older adults, the homeless, and those without air-conditioning are most susceptible to heat-related illnesses.

"Heat waves are silent killers," tweeted Stefan Rahmstorf, a climate scientist at Postdam University. "The 2003 European heat wave has caused about 70,000 fatalities. Last year's hot summer in Germany has been estimated to have caused at least 1,000 excess deaths."

The hottest temperatures are likely to focus western to central mainland Europe, escalating Tuesday and peaking Wednesday into the end of the work week.

In Paris, temperatures may approach 100 degrees Wednesday through Friday. The city along with more than half of France is under an orange alert, the second highest level on the country's heat scale. The scale was instituted after the 2003 summer heat wave, blamed for 15,000 deaths.

Farther northeast, Berlin should also flirt with the century mark. Even Copenhagen on the main island of Denmark is set to head into the 80s.

A list of June national records that may be in play includes Austria (101.5 deg), France (106.7 deg), Germany (101.3 deg), and Switzerland (99.1 deg), as well as several others in the region. Some all-time records, mostly set in July or August, may also be threatened.

In Britain and Ireland, temperatures are not forecast to be as intense as the south but some spots should see readings into the 80s, which is considerably above normal for the time of year. Farther east in southern Sweden, as well as neighboring Denmark, some spots could approach 90 degrees.

Part of the cause for the massive early-season heat wave is a pair of powerful high pressures. One is near Greenland, and the other is over north central Europe. As they become linked and flex over the coming days, they'll also act to block a low pressure system to their south, which would draw cooler air over Europe.

Together the zones of high pressure, combined with the cooler low pressure zone offshore, will steer a so-called "Spanish plume" over mainland Europe and United Kingdom. The hot air plume, sourced from deserts in Spain and the Sahara, will spill over France, Britain and Germany. The result can be a lot of falling records, and severe thunderstorms at times.

In some areas the resulting heat will an intensified version of what they've deal with already, while in others it will come more as a shock.

June has so far been dominated by warmth in eastern and central Europe, with cooler than normal conditions over western parts of the continent.

Germany is seeing a top five warmest June, with cities like Potsdam in the northeast part of the country on its way to its warmest June on record. But farther west, this new onslaught of heat represents something of a pattern change.

"So far this summer it's often been cool and it's often been raining," notes the BBC.

This early heat wave is the latest in a number of historic episodes of heat in recent years. Just last summer the continent saw relentless record temperatures coupled with unusually dry conditions. As a result, drought and wildfires were rampant.

"The hottest summers since 1500 AD in Europe were: 2018, 2010, 2003, 2016, 2002," wrote Rahmstorf. It is believed that heat waves like 2018's in the region are at least twice as likely thanks to climate change.

The broader weather regime behind this heat wave has connections to the stagnant high-pressure zone responsible for the big Greenland melt event in mid-June. Both the Greenland melt and this heat wave are connected to a so-called "blocking pattern" comprised of big and lumbering high pressure zones in the northern latitudes that can become stuck in place and lead to extreme weather. Such patterns may be becoming more common in a warming world.

While the current heat wave is set to peak later this week, warmer than normal conditions seem likely to persist for longer in much of western and central Europe. Any notably cooler air seems likely to remain centered near the Nordic states and into Asia for the time being.