Remember the Pentecost weekend of 2014. A series of intense storms hit Western and Central Europe. These storms followed a heatwave. The German Weather Service described the storm as one of the most violent in decades. Some German media called the low-pressure system “Ela”.
Let’s delve into the synoptic situation. On June 4th, 2014 a small low-pressure system formed south of Greenland. The system deepened and expanded as it moved southeast. It became stationary off the coast of Western Europe. A hot, moist air mass moved into Western Europe. Temperatures reached 38 degrees Celsius. This created high instability. A strong jet developed over Western Europe. This created windshear that organized thunderstorms into supercells.
The storms began in southwestern France on June 6th. By June 8th, strong supercells developed over northern France, Belgium, and Germany. These storms brought severe winds and hail. On June 9th, the storms moved into the BeNeLux states. They continued to produce hail and strong winds. They eventually reached northwestern Germany. The storms merged into a mesoscale convective system MCS.
New storms formed over northern France. One supercell passed directly over Paris. This supercell produced hail up to 10 cm in diameter. The northern France MCS reached the Netherlands. Its outflow boundary caused new supercells to form in North Rhine-Westphalia. The MCS restrengthened and caused severe winds.
As evening approached, the supercells reached Belgium. They grew into a line of severe thunderstorms. This MCS crossed into western Germany around 8 pm. It developed a bowing segment. By 9 pm, the MCS became a violent bow echo. It moved across the Rhine-Ruhr region. Hurricane-force winds affected about 10 million people. The storm became the most damaging weather event in decades.
All six fatalities from Ela resulted from the intense bow echo. The damage cost about 650 million euros. Peak winds of 144 km/h were measured in Du00fcsseldorf. Some believe windspeeds reached 150 km/h. Around 40 liters of rainfall fell per square meter.
The bow echo weakened after 11 pm. It continued to produce strong winds as it moved into central Germany. The system dissipated after crossing into Poland.
On June 10th, supercells merged into an MCS over the Paris area. This system caused more damage. It dissipated in northern Germany around 9 am.
The trough moved northward on June 10th. The jet with the strongest windshear no longer overlapped with the highest instability. The risk area shifted eastward. Severe thunderstorms still developed. Hail and strong winds were recorded.
On June 11th, a high-pressure system influenced Iberia and western France. A large pocket of instability remained over eastern Germany, western Poland, and parts of Czechia. Thunderstorms focused on this area. Three tornadoes touched down in southern Mecklenburg-Vorpommern. The storms also produced large hail and severe winds.
Between June 7th and 10th, Saint-Sauveur-Marville received 55mm of rain. This equaled several weeks’ worth of rainfall.
On June 9th, there were over 64,000 lightning discharges in the Netherlands. The bow echo produced an estimated 113,708 lightning strikes across Germany.
Ela caused approximately 900 million dollars of insured losses. It was the second most damaging summer storm in fifteen years. Property insurers dealt with 350,000 claims. Auto insurers counted another 100,000 claims.
Losses from hail events in Europe rose to over 5 billion dollars in the summer of 2014.
“Ela 2014 – Die Natur braucht uns nicht”. This inscription serves as a stark reminder of nature’s indifference to human affairs. A humbling thought as we reflect on the immense power displayed during those Pentecost weekend storms.