2020–21 European windstorm season

The 2020–2021 European windstorm season was the sixth instance of seasonal European windstorm naming in Europe. This is the second season in which the Netherlands participates, joining Ireland's and the United Kingdom's meteorological agencies. The new season's storm names were released on 1 September 2020. Storms that occur up until 31 August 2021 will be included in this season. The Portuguese, Spanish, and French meteorological agencies will again collaborate too, joined by the Belgian meteorological agency.

Background and naming
In 2015, the Met Office and Met Éireann announced a pilot project to name storm warnings as part of the "Name our Storms" project for wind storms and asked the public for suggestions. The meteorological offices produced a full list of names for 2015–2016 through to 2017–2018, common to both the United Kingdom and Ireland, with the Netherlands taking part from 2019 onwards. Names in the United Kingdom will be based on the National Severe Weather Warning Service, when a storm is assessed to have the potential for an Amber ('be prepared') or Red ('take action (danger to life)') warning.

There are two main naming lists: one created by the national meteorological agencies of the United Kingdom, Ireland, and the Netherlands, and another created by the equivalent agencies from France, Spain, Portugal, and Belgium. Additionally, former Atlantic hurricanes will retain their names as assigned by the National Hurricane Center of the United States.

Also, some of these storms may be of tropical origins. For example, ex-Hurricane Lorenzo of 2019 made landfall in Ireland and the United Kingdom. All details on tropical storms and hurricanes can be found on the National Hurricane Centre.

Western group (United Kingdom, Ireland and the Netherlands)
The following names have been selected for the 2020–2021 season.

South western group (France, Spain, Portugal and Belgium)
This will be the fourth year in which the meteorological agencies of France, Spain and Portugal will be naming storms that affect their areas. This naming scheme partially overlaps that used by the United Kingdom, Ireland and the Netherlands, as storms named by the other group of agencies will be used reciprocally.

Storm Alex
Storm Alex, named by AEMET and Météo-France on 30 September, formed near Brittany on 1 October after undergoing explosive cyclogenesis. Because of this storm, one department in France, the Morbihan, was upgraded to the red alert for strong winds at 4:00 pm Central Time.

Alex caused much damage in the department of the Morbihan. Trees were blown down and roads and railways were closed due to flooding and the trees which were downed by the strong winds. Around 100,000 power outages were reported in Brittany. Météo-France observed local strong winds over land (142 km/h in Granville, 132 km/h in Sarzeau, 131 km/h in Vannes, 129 kph in Cholet).

The storm led to advection of Mediterranean air northwards where it interacted with the coastal topography producing a heavy rainfall in southeast France, known as a "Mediterranean Episode". The department of the Alpes-Maritimes was issued with a red alert for high amounts of rain and flooding. Météo-France reported a maximum of 571 mm in 24 hours in Mons. More generally, 250 to 300 mm were reported in the department of the Alpes-Maritimes. Météo-France also reported 60 to 100 mm in departments of the Drôme, Ardèche, Rhône, Ain, Saône-et-Loire, Jura and Côte-d'Or. 104 mm in 24 hours in La Rochepot, Côte-d'Or, set a new a record for Burgundy in October. At least 6 people were reported dead; 1 in Brest and 5 in the Alpes-Maritimes with 7 missing in total and for a dozen others families and authorities don't have any news. In Italy, 2 deaths were reported with 1 person missing. Strong gusts caused one death in each of Austria, Poland and Czech Republic.

Many yellow and amber weather warnings were issued in the United Kingdom for strong winds and heavy rain. As of 21:00 BST, the Met Office reported the maximum rainfall total to be 78 mm at Liss, Hampshire, with the maximum gust of 71 mph being recorded at Berry Head, Devon. Many of the fatalities were caused by the ensuing landslides.

On 5 October 2020, the death toll of the floods affecting France and Italy rose to 7 as three bodies were found in Nice, bringing the death toll in France to four, meanwhile there were three dead people in Italy. The region of Piedmont witnessed levels of rain not recorded since 1958, in which it reached a record 630 mm of rain in Sambughetto in just 24 hours. By 6 October, the death toll reached 12 with a further 20 still missing, as there were another five dead people in Italy, including a worker who was found in the Italian region of Liguria, having gone missing during the beginning of the floods. Moreover, cemeteries in Saint-Martin-Vésubie and Tende were partially washed out by the floods, in addition to seven Canadian black wolves which were lost from a wildlife park in Nice. Monaco's Minister of State Pierre Dartout announced that €4m would be distributed to the affected regions including French communities in Alpes-Maritimes and Italian municipality of Ventimiglia. Another 3 people were found dead, and another person went missing, bringing the number of missing people to 21, and the death toll to 15 individuals as of 7 October. By 3 October, one more individual had gone missing, but the other 21 missing people were found safe and rescued, bringing the number of missing persons to 1 individual. In addition, an Italian firefighter was killed by a falling branch.

Storm Barbara
Barbara developed from a wave on a front trailing from a complex of low-pressure southwest of Portugal on 19 October. It moved northwest over the Iberian peninsula into the Bay of Biscay, moving into the English Channel and over the North Sea, then into Scandinavia, bringing heavy rain and, in some places, their first snow of the season.

Strong gusts and some damages was reported by the Meteo-France in association with the storm over parts of Spain, Portugal and France. Over 76,000 households in the latter's southwestern region lost power alone, while also causing significant damage to the electricity department. Numerous trees and power poles were also downed due to strong winds. It also killed an individual in Digoin, Burgundy when a tree collapsed on him in his garden. Total damages from the storm were estimated at greater than $50 million.

Storm Aiden
Storm Aiden was named by Met Éireann senior executive Aidan McLaughlin on 30 October 2020.

On 30 October, Met Éireann issued a Status Orange wind warning for counties Kerry, Cork, Waterford, Wexford, Kilkenny, Carlow and Wicklow, valid between 31 October 2020 05:00 and 31 October 2020 10:00. An additional Status Orange wind warning was issued for counties Donegal, Sligo, Mayo, Galway and Clare, valid between 31 October 2020 08:00 and 31 October 2020 16:00. In both warnings, mean wind speeds of 65 to 80 km/h were expected, with severe and damaging gusts of up to 130 km/h also expected. A Status Yellow wind warning was issued for all remaining counties, valid between 31 October 2020 01:00 and 31 October 2020 15:00.

Over 8,000 homes and businesses were left without power as the storm battered the country with severe gusts of up to 130 km/h at Malin Head, Ireland, which led to fallen trees and flooding. The highest gust in the UK was 79 mph at Altnaharra, Sutherland.

Storm Clement
Storm Clement was named by AEMET on 27 November. It was located near the Azores Islands when it was named. By 28 November, Clement had moved slightly farther south and was affecting the Canary and Madeira Islands. The storm stalled, keeping the worst conditions away from mainland Europe. Portugal and some parts of Western Spain did see Clement's outer bands. The NHC was also monitoring the system for tropical or subtropical development. After stalling for about 4 days, the system dissipated on 2 December.

Storm Dora
Storm Dora was named on 2 December. It brought rain and snow to the UK, France, the Iberian Peninsula, and parts of Scandinavia. Areas closest to the coast saw some winds of more than 62 mph. By late 4 December, the system had become very disorganized, and early on 5 December was absorbed by another low-pressure system, which was named Xunav by the Free University of Berlin.

Storm Ernest
Storm Ernest was named on 7 December by AEMET and Meteo France. It moved over the Bay of Biscay and then onto land bringing rain and wind to Northern Spain and the South of France. Its impacts then moved toward Italy and Switzerland, bringing rain and as well as snow in the mountains, but weaker winds. After reaching the shores of Italy, the system turned toward the northeast. Its rain then affected the Balkan countries and brought snow and/or mixed precipitation to parts of Belarus, Russia, and the Baltics, with its centre over Romania and Bulgaria. The system dissipated by 12 December.

Storm Bella
Storm Bella was named on 25 December by the Met Office. It hit the UK and the Netherlands, bringing wind gusts of up to 73 mph or more. There is also the threat of flooding, which has forced many people to evacuate their homes. The system was notably large, since the low pressure covered most of the area between Greenland's east coast and Norway's west coast and the area between Svalbard and Scotland on 25 December. The Norwegian coast was affected, causing much of the region to have a White Christmas. After making landfall, the weakening system turned north, and eventually dissipated in Central Scandinavia.

Storm Filomena
Storm Filomena was named by AEMET (Agencia Estatal de Meteorología) on 5 January. It started as one system that split into two systems and hit Spain and Portugal back to back from 6 to 9 January. Near the coasts, wind gusts of up to 50 mph occurred, as well as 1-2 in of rain. Further inland and in higher elevations, snowfalls of up to 2 ft occurred, with areas of the city of Madrid receiving snow accumulation of up to 24 in. According to AEMET, Filomena was the largest snowstorm in Spain since 1971. In the mountains, wind gusts of up to 75 mph accompanied the large snow totals. Due to the unprecedented amount of snowfall, some unsuspecting motorists were trapped on the roads for hours. 4 deaths have also been reported; two in Malaga due to flooding, and two homeless men who froze to death. One was in Madrid, the other in Calatayud. On 9 January, another 8 in of snow fell in Madrid. The system began to get very disorganized on January 12, and was absorbed by a system named Dimitrios (see below), by the 13th.

Storm Christoph
Storm Christoph was named on 18 January by the Met Office. It brought heavy flooding to homes in the United Kingdom and a snowstorm in Northern England. After moving away from the United Kingdom, it hit Scandinavia with strong winds and snow. Norway's meteorological service gave the storm the name "Frank". Northern Norway was hit by strong winds up to 50 m/s, and combined with low temperatures (−15 °C) the meteorological service warned for high risks of frostbite if staying outdoors. Heavy snowfall hit northern Sweden, some places bringing up to 1 meter of snow. Trains were halted in the regions of Jämtland and Norrbotten, and traffic was disrupted in all of Norrland as well as parts of eastern Norway. Snow and winds cut power to several thousand people in eastern Norway and disrupted the mobile network. The storm stalled over the Norwegian Sea for about 4 days, then dissipated by January 26.

Storm Gaetan
Storm Gaetan was named on 19 January. It followed a similar path to the one Christoph took. It hit Spain and the United Kingdom with strong winds, rain, and some snow. It was absorbed into Storm Christoph on 20 January.

Storm Hortense
Storm Hortense was named by AEMET on 20 January. It hit the Iberian Peninsula on 21 and 22 January, bringing wind gusts of up to 144 kph, though there were some unofficial reports of 170 kph. The system then affected Finland, and dissipated by January 25.

Storm Ignacio
Storm Ignacio was named on 22 January by AEMET and was active until the 26th. The storm moved over Spain and Italy with heavy rain. After that, the storm moved into East-Central Europe, bringing up to 12 in of snow in some areas.

Storm Justine
Justine was named on 26 January by IPMA. It caused rain and strong winds for Spain and France. Parts of Ireland and Southern England also recorded snowfall totals of up to 5 in. There were wind gusts as high as 85 mph along the coasts of Northern Spain and Southwestern France. It was absorbed by another system that brought significant snow to areas of Croatia and Slovenia.

Storm Darcy
Storm Darcy was named on 5 February and brought high winds and heavy snowfall to Ireland, Germany, Netherlands and the United Kingdom on 7–8 February. In the Netherlands and Germany, it resulted in the heaviest snowfall in a long while. The Netherlands announced a red weather alarm for 7 February for the whole country for the first time since 2012. Locally in North Rhine-Westphalia, and in the Dutch Twente and Achterhoek regions and Arnhem–Nijmegen metropolitan area, the snow reached as tall as 30 cm. Public transport schedules in the Netherlands were very disrupted. From the afternoon of 7 February and in the morning of 8 February, train traffic was completely stopped due to frozen switches. On 8 February, national Dutch newspapers including De Telegraaf, De Volkskrant and Algemeen Dagblad did not print any physical copies due to the bad weather. The forecast prevalence of cold temperatures at night (down to -20 °C) led to increasing hopes for the first Elfstedentocht (long-distance ice skating event) since 1997, although the event was cancelled in November 2020 due to the pandemic.

Storm Karim
Karim was named on 17 February. Orange warnings for wind were issued for parts of the northwest corner of Spain, alerting residents of wind gusts of up to 109 kph. The system also affected most of Ireland and Scotland, bringing rain and moderate wind.

Storm Evert
Evert named by the Met Office on 29 July was a late season storm which brought strong winds and heavy rain to parts of the United Kingdom. Amber wind warnings were issued for much of the Cornwall as well as the Isles of Scilly with yellow wind warnings having been issued for much of the south-west and south coast of England, as well as Southern Wales.

Other systems
A powerful cyclone, named Aila by the Finnish Meteorological Institute, struck Finland, on 16 September and continued to cause disruption through the following day. The worst impacts were felt in south-central Finland, just north of Helsinki. In these areas, the storm brought heavy rain and wind. There were waves up to 19 ft in height and winds up to 77 mph. The most rain fell in Kajaani, where they got as much rain as they get in all of September from Aila. In terms of physical impacts, the storm disrupted ferry traffic, brought down trees, and cut power to at least 90,000 homes.

Cyclone Ianos, a medicane named by the METEO unit of the National Observatory of Athens moved through Greece between 17 and 18 September. It resulted in the death of at least 3 people and train services connecting the north and south of Greece being cut off. The storm came with significant flooding and winds near or above hurricane-force.

On 2 November the remains of Hurricane Zeta hit Finland. It was not given a name by the Finnish Meteorological Institute, but was commonly referred to as Topi, especially by the Swedish-language media in the country. It brought winds up to 35,8 m/s, cutting power to more than 16,000 people and disrupting the railway lines. The storm also brought high coastal waters, the water levels rising as much as 90 cm in Jakobstad (Finnish: Pietarsaari).

On 19 November, the extratropical remnants of Hurricane Eta hit Finland and were named Liisa (Lisa in Swedish) by the Finnish Meteorological Institute. It brought wind of up to 55 mph, cutting power to more than 64,000 people. Trees and buildings were damaged too. Heavy rain also induced travel difficulties, with slippery roads causing poor driving conditions, as well as damage to rail tracks forcing train services to be delayed or cancelled throughout the country.

Storm Dimitrios, named by the Free University of Berlin, affected Northern Europe on from 10 to 12 January. Its most notable effects were ln Sweden, where the SMHI issued a Red Warning for snow in parts of Västernorrland County, which was the first time they had done so since 2010. The storm caused blizzard conditions in that area, with wind gusts of 40 mph at times and 18 - 24 in of snowfall in some areas west of the city of Örnsköldsvik. The storm left 6,000 customers in Northern Sweden without power. Strong winds and rain were also present in Finland and Germany.

Storm Klaus, a small but slightly dangerous storm, was named by the FUB on 8 March. The storm brought showers, heavy rain and isolated wind gusts of up to 160 km/h. The system primarily affected Germany and Norway.

On 4 May, a late-season storm named Eugen by the Free University of Berlin affected Northern France and Belgium, bringing gusts up to 130 km/h. In Boulogne-sur-Mer, it equalized the windspeed record for May with 133 km/h.

On July 14, a system named Bernd caused the 2021 European floods in Germany, Belgium, and the Netherlands.