Europe braces for storms and heavy rain as 'omega heat dome' retreats after record 41 C heat

The "omega heat dome" that drove record-breaking temperatures above 41 degrees Celsius in Germany is gradually retreating from Europe this week. But as some regions brace for temperatures plunging up to 12 degrees below seasonal norms, forecasters are warning of a new weather emergency — powerful thunderstorms and torrential downpours.

According to weather specialist outlet Severe Weather Europe, the heat wave that recently struck central Europe and the Balkans is weakening as atmospheric circulation shifts. A strengthening high-pressure ridge over the Atlantic is pushing cold Nordic air southward into central and eastern Europe.

As a result, daytime highs across most of central and eastern Europe are expected to fall 4 to 8 degrees below seasonal averages, dropping back below 30 C and returning to more typical summer levels.

The sharpest temperature drops are forecast for Thursday in northern Italy, Slovenia, Croatia, Austria, the Czech Republic, Slovakia and Poland. On Friday and Saturday, temperatures across parts of the southern Balkans, southern Italy and Greece are expected to fall as much as 10 to 12 degrees below normal.

Nighttime temperatures will also drop sharply. From midweek through the weekend, morning lows in many areas are expected to dip into the low-to-mid teens Celsius, with some inland areas recording around 10 C — a development that should significantly ease the urban heat island effect that persisted throughout the heat wave.

Yet forecasters warn that another weather hazard may fill the void left by the retreating heat. As the descending cold air collides with the hot, humid air over the Mediterranean, intense thunderstorms and heavy rainfall are expected to strike Italy, Greece, Romania and areas along the Black Sea coast.

Analysts note, however, that the prolonged dry spell means the rain alone will not be enough to relieve the drought conditions and elevated wildfire risk that built up during the heat wave.

The heat wave was powerful enough to rewrite weather records across Europe. Saarbrücken, Germany, saw temperatures soar to 41.3 C, surpassing the previous national record set in 2019, and June heat records were broken at 147 weather stations across the country.

The heat wave that blanketed Europe was attributed to the omega heat dome phenomenon, in which hot air is trapped by a high-pressure system shaped like the Greek letter omega (Ω). In France, 55 people drowned after entering rivers and lakes to escape the heat, and four infants died after being left in vehicles. Spain's Carlos III Health Institute recorded 327 heat-related deaths.

Not all of Europe is escaping the heat simultaneously, however. The Iberian Peninsula — Spain and Portugal — is forecast to see temperatures remain near 40 C this week, highlighting a stark regional divide within the continent.

Meteorologists say extreme swings between heat waves and heavy rainfall are becoming increasingly frequent across Europe in rapid succession. They cautioned that such dramatic temperature shifts heighten atmospheric instability, raising the likelihood of stronger downpours, gusts and hail, and urged governments to monitor weather forecasts closely.