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The 2023–2024 European windstorm season is the ninth season of the European windstorm naming in Europe. The new season's storm names were announced on 1 September 2023. Storms that occur up until 31 August 2024 will be included in this season. This was the fifth season where the Netherlands participated, alongside the United Kingdom's Met Office and Ireland's Met Éireann in the western group. The Portuguese, Spanish, French and Belgian meteorological agencies collaborated for the seventh time, joined by Luxembourg's agency (South-western group). This is the third season where Greece, Israel and Cyprus (Eastern Mediterranean group), and Italy, Slovenia, Croatia, Montenegro, North Macedonia and Malta (Central Mediterranean group) named storms which affected their areas.

Background and naming

Definitions and naming conventions

There is no universal definition of what constitutes a windstorm in Europe, nor is there a universally accepted system of naming storms. For example, in the Western Group, consisting of the UK, Ireland, and the Netherlands, a storm is named if one of the meteorological agencies in those countries issues an orange warning (amber in the UK), which generally requires a likelihood of widespread sustained wind speeds greater than 65 km/h, or widespread wind gust speeds over 110 km/h. (Required wind speeds vary slightly by agency and by season.) Both the likelihood of impact and the potential severity of the system are considered when naming a storm. The Southwest Group of Spain, Portugal, and France share a similar storm-naming scheme, though their names differ from those used by the Western Group. In Greece, however, naming criteria were established for storms when the storm's forecasted winds are above 50 km/h over land, with the wind expected to have a significant impact to infrastructures. In Denmark, a windstorm must have an hourly average windspeed of at least 90 km/h (25 m/s).

The Meteorology Department of the Free University of Berlin (FUB) names all high and low pressure systems that affect Europe, though they do not assign names to any actual storms. A windstorm that is associated with one of these pressure systems will at times be recognized by the name assigned to the associated pressure system by the FUB. Named windstorms that have been recognized by a European meteorological agency are described in this article.

Naming conventions used in Europe are generally based on conditions that are forecast, not conditions that have actually occurred, as public awareness and preparedness are often cited as the main purpose of the naming schemes–for example, a reference. Therefore, an assignment of a storm name does not mean that a storm will actually develop.

Western Group (United Kingdom, Ireland and the Netherlands)
In 2015, the Met Office and Met Éireann announced a project to name storms as part of the "Name our Storms" project for windstorms and asked the public for suggestions. The meteorological offices produced a full list of names for 2015–2016 through 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.

The following names were chosen for the 2023–2024 season in the United Kingdom, Ireland, and the Netherlands. For a windstorm to be named, the United Kingdom's Met Office, Ireland's Met Eireann, and the Netherlands KNMI have to issue an amber weather warning, preferably for wind, but a storm can also be named for amber warnings of rain and snow (e.g. Storm Arwen in 2021).

South-western Group (France, Spain, Portugal, Belgium and Luxembourg)
This was the seventh year in which the meteorological agencies of France, Spain and Portugal named storms that affected their areas.

Central Mediterranean Group (Italy, Slovenia, Croatia, Bosnia & Herzegovina, Montenegro, North Macedonia and Malta)
The following names were chosen for the 2023–24 season in Italy, Slovenia, Croatia, Bosnia & Herzegovina, Montenegro, North Macedonia and Malta.

Eastern Mediterranean Group (Greece, Israel and Cyprus)
The Eastern Mediterranean Group works slightly differently compared to other naming lists, instead of ending a season on the 31 August of that year, they end the season on the 30 September of that year. These are the names that were chosen for the 2023–24 season in Greece, Israel and Cyprus.

Northern Group (Denmark, Norway and Sweden)
This naming group, like the naming from the Free University of Berlin, does not use a naming list but names storms when it has not received a name by any other meteorological service in Europe and is projected to affect Denmark, Norway or Sweden.

Season summary

All storms named by European meteorological organisations in their respective forecasting areas, as well as Atlantic hurricanes that transitioned into European windstorms and retained the name assigned by the National Hurricane Center:

Storms

Storm Agnes (Kilian)

Storm Agnes was named by the UK's Met Office on 25 September 2023 and was forecasted to bring strong winds and heavy rain to much of the UK and Ireland. The storm, which was also named Kilian by the Free University of Berlin and the Deutscher Wetterdienst, impacted the British Isles on 27 September.

Storm Babet (Viktor)

Storm Babet was named by the United Kingdom's Met Office on 16 October and affected large parts of western and northern Europe. It first affected Portugal and southwestern Spain with strong winds, heavy rains and floods on 16–17 October, subsequently moving to northern Europe. The Met Office issued several yellow rain and wind warnings for large parts of the UK, along with amber rain warnings for parts of north eastern England and Scotland. A rare red weather warning was issued for eastern parts of Scotland.

Met Éireann issued Yellow rain warnings for most of Ireland. An orange rain warning for south western Ireland was also issued, and there was flooding in the south of the Island, especially the east of County Cork; Midleton was particularly badly hit.

A rare red warning for rainfall was issued across portions of eastern Scotland by the Met Office on 19 October. A wind gust of 124 km/h (77 mph) was registered at the coast in Inverbervie. In the highlands, Cairn Gorm summit recorded a gust of 185 km/h (115 mph). In Brechin, Scotland, residents were asked to evacuate their homes by the local council.

In Denmark, southern Sweden and northern Germany, the wind caused some material damages, fallen trees and cancellations of ferries, trains and planes, but the most serious effect was a storm surge, with large amounts of seawater being pushed by the wind into the westernmost Baltic Sea and Danish straits (unlike floods in Great Britain, Ireland and the Iberian Peninsula that primarily were caused by heavy rain). In parts of Denmark (southeastern Jutland, southern Funen, southern Zealand and smaller islands in the area) and Germany (eastern Schleswig-Holstein), it caused the highest floods in more than a century, with some places in Denmark having sea levels that were up to above normal and in the Germany up to above normal. In certain, particularly exposed places, people were evacuated after levees broke and houses were flooded. On the opposite, western side of Jutland and Schleswig-Holstein, the waters were forced away from the shore by the wind, with sea levels up to below normal, stranding boats and preventing several ferries from running because of insufficient water depths.

There have been at least six recorded fatalities: a 57 year old woman died after being swept into a river in Angus (Scotland), a 56 year old man died after his van hit a tree near Forfar in Angus, a man in his 60s was killed being swept away because of flood waters near Cleobury Mortimer (England),, a 33 year old woman was killed on the German island of Fehmarn when her car was hit by a falling tree, and a woman in her 80s in Chesterfield died in flooding. The police searched for a man trapped in a vehicle in floodwater near the Aberdeenshire village of Marykirk, but he was later found dead.

Storm Aline (Wolfgang)

Storm Aline was named by Spain's state weather forecast agency AEMET, while Wolfgang was the name given by the Free University of Berlin both on 18 October 2023. The storm caused heavy rainfall across several parts of Spain and France. More than 20 flights were diverted from Malaga Airport and a gust of 100 km/h was reported in Cabrera.

Storm Bernard (Xanthos)

Storm Bernard was named by the Portuguese Institute of the Sea and Atmosphere (IPMA) on 22 October 2023, but the Free University of Berlin noticed and named this system, Xanthos, on 21 October 2023 instead

Storm Celine (Benj)

Storm Celine was named and reported on 28 October 2023 by the Portuguese Institute of the Sea and Atmosphere (IPMA), at around 1 pm local time that same afternoon. A cold front will pass through and move down south, and this will cause not only persistent rain but also heavy showers accompanied by thunderstorms. IPMA also predicted wind gusts as high as 90 km/h in the highlands and waves up to 6 m in height.

The storm will pass through Central Portugal by 29 October (Sunday) and by 30 October (Monday), it will sweep not only Southern Portugal but also leaving Spain's nine provinces of five autonomous communities with yellow weather warnings for heavy rain. Costa del Sol will have temperatures as high as 25 °C while inland will have a dip in temperatures as low as 18 °C in Ronda. Western France had weather warnings issued on Monday and will continue to be in effect up until 31 October (Tuesday).

As of 30 October, there have only been one reported death: 70 year old elderly lady was pronounced dead on the scene by a falling tree Sunday afternoon (France).

Storm Ciarán (Emir)

Storm Ciarán was named by the United Kingdoms Met Office on 29 October. It is expected to bring winds of 90 to 120 km/h (60 to 70 mph) widely with >130 km/h (>80 mph) on some coasts. More heavy rainfall is expected to fall which will exacerbate the flooding from Storm Babet a week prior. A large yellow weather warning for rain and wind in place for the South Wales, Devon and Cornwall, south coast and the east coast of East Anglia. Warnings are likely to be upgraded in the coming days. The Met Office long range is forecasting that Storm Ciaran will move away on 3 November (Friday), with many places still with blistering winds and rain spells. The Channel Islands are due to be hit with gusts around 95 mph with schools closed and a red weather warning in place. On 1 November (Wednesday) this was updated to a Force 11 violent storm.
The storm will impact the Netherlands on 2 November (Thursday). The Met Office stated Storm Ciarán is undergoing explosive cyclogenesis as of 1 November.

Season effects

See also
Weather of: 2023
Tropical cyclones in 2023

References

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