2018–19 European windstorm season

United Kingdom and Ireland

France, Spain and Portugal

This will be the second year in which the meteorological agencies of France, Spain and Portugal will be naming storms which affect their areas. This naming scheme is partially overlapping with that used by the UK and Ireland, as storms named by the other group of agencies will be used reciprocally.^[4][5]

Additionally to these naming systems the Free University of Berlin also names high and low pressure areas through its "Adopt a vortex" programme. The Nordic nations of Denmark, Norway and Sweden also name storms with more limited reciprocation.^[6] Other nations may also name storms either through their national meteorological institutions or popularly.

Ex-Hurricane Helene

Helene
Area affected	Portugal, Spain, Ireland, United Kingdom
Date of impact	16–18 September
Maximum wind gust	78 mph (126 km/h), Cairngorms, Scotland[7]
Lowest pressure	989 hPa (29.2 inHg) (while extratropical)
Fatalities	None
Power outages	None
Damage	Minimal

While still a tropical cyclone, Hurricane Helene affected the Azores from 15–16 September. The system subsequently completed an extratropical transition on 16 September as it accelerated north-eastwards towards the British Isles,^[8] with the outer bands of Storm Helene causing minimal impacts in north-western Spain and Portugal.

Storm Helene crossed the UK and Ireland on 17–18 September, with the Met Office and Met Eireann issuing yellow wind warnings.^{[9] [10]} The Met Office's yellow warning of wind covered southern England, the Midlands and Wales overnight from 17–18 September, with forecasts predicting winds of up to 60 to 70 mph (97 to 113 km/h).

Helene was downgraded as it approached the British Isles, with winds gusting to only 40 to 50 mph (64 to 80 km/h) in isolated locations; as a result, all warnings were cancelled on 18 September as Helene was still crossing the United Kingdom.

Hurricane Helene developing into an extratropical cyclone on 16–17 September 2018

Storm Ali

Ali
Area affected	Ireland, Norway, United Kingdom
Date of impact	18–20 September
Maximum wind gust	102 mph (164 km/h) recorded at Tay Road Bridge, Scotland[11]
Lowest pressure	967 hPa (28.6 inHg)[12]
Fatalities	2
Power outages	286,000+
Damage	Unknown

Repairs underway to a house in Sheffield on 20 September that had had its roof ripped off by Storm Ali.

Storm Ali was named on 18 September by Met Éireann and Met Office, who both issued Amber weather warnings for wind associated with Ali. The centre of circulation of Ali made landfall in south-western Ireland in the early hours of 19 September, crossing into Northern Ireland before re-emerging into the Atlantic and then making a second landfall close to Ullapool in north-western Scotland at around 14:00. The highest wind gust recorded in the Republic of Ireland was 143 kilometres per hour (89 mph) at Mace Head weather station in County Galway.^[13][14] The highest gust record in the United Kingdom was 102 miles per hour (164 km/h) recorded on the Tay Road Bridge in Scotland.^[15] The winds on this storm were equivalent to a Category 2 on the Saffir-Simpson scale.

Storm Ali killed two people in Ireland and the United Kingdom. A caravan was blown over a cliff onto a beach near the village of Claddaghduff in County Galway, killing a woman who was visiting from Switzerland.^[16] In County Armagh, a man in his 20s was killed by a falling tree.^[17] Falling trees also severely injured a woman in Cheshire.^[11] There was also severe tree damage in the Galway City and County region, which led to numerous school and road closures. Electricity supplies were lost to more than 100,000 homes across Northern Ireland, with more than 25,000 remaining without power into the following morning; the worst affected areas for power outages were Omagh, Dungannon and Enniskillen.^[17] Across the border in the Republic of Ireland, more than 186,000 properties lost electricity during Ali, of which 119,000 had power restored by the end of the day.^[17]

In County Antrim, the M1 motorway was closed in both directions for several hours after power cables fell across the carriageways.^[18] Enterprise trains between Belfast and Dublin were delayed for up to seven hours due to debris on the tracks.^[17] Services between Belfast and Derry were suspended, and a blanket speed restriction of 50 mph was enforced on all NI Railways services pending track inspections, causing widespread delays.^[17] There were also delays to flights at Belfast International Airport.^[17] In Greenock in Scotland, the MS Nautica cruise ship broke free from her moorings and drifted for several hours before being rescued by tugboats.^[11]

A major incident was declared by police in Dumfries and Galloway after many people were injured by flying debris; schools were placed on lockdown for the safety of students, as Ali's highest winds in this area occurred around the end of the school day.^[11] On the Highland Main Line, a freight train was derailed after striking fallen tree branches.^[11] In Cumbria, fallen trees and power lines caused disruption to transport and left homes without power; overturned lorries caused the M6 motorway to close for several hours, and Virgin Trains services along the West Coast Main Line were delayed or cancelled between Preston and Glasgow Central.^[11] Dozens of trees fell or were damaged across the city of Sheffield, where council housing stock suffered considerable damage, including one housing block which had its roof ripped off in the Gleadless Valley area of the city.^[19]

After clearing the UK, Ali made landfall in Norway, where several thousand homes were left without power in the west of the country.^[20]

Storm Bronagh

Bronagh
Area affected	Ireland, Norway, United Kingdom, Denmark, Germany, Poland
Date of impact	20–25 September
Maximum wind gust	96 mph (154 km/h), Høllen, Norway
Lowest pressure	969 hPa (28.6 inHg)[21]
Damage	Considerable flooding damage, particularly in the Sheffield area

Storm Bronagh broke the record for the wettest September day ever recorded in Sheffield, resulting in the city's most serious flooding event since June 2007.

Bronagh first developed as a wave depression close to the southeast coast of Ireland.^[22] The storm was named on 20 September, and was expected to develop further over the British Isles. Yellow weather warnings were issued with the "possibility" that further upgrades to Amber warnings may be needed depending on how Bronagh developed over the UK. However, Bronagh did not develop over the Isles, and instead strengthened over the North Sea. Thus, no Amber alert for Bronagh was issued by the UK Met Office.^[23]

Bronagh brought heavy rainfall to southern Ireland, Wales, and northern England. Heavy rainfall fell across Wales and northern England on 20 September as Bronagh approached. In Sheffield, 66.2 millimetres (2.61 in) of rain fell in a 24 hour period, breaking the previous record of 58.9 millimetres (2.32 in) set on 14 September 1994 for the city's wettest September day since records began.^[24] Rainfall accumulations reached 70 millimetres (2.8 in) widely across Wales and northern England, with some parts of Wales recording up to 100 millimetres (3.9 in) of rain.

As a result of heavy rainfall from Bronagh, widespread flooding was reported. Flash flooding in Sheffield was the worst to affect the city since June 2007. Along the A6178 Sheffield Road between Sheffield and Rotherham, rapidly rising floodwaters caused cars and vans to become stranded.^[25] In nearby Tinsley, a woman had to be rescued from her car after becoming trapped in rising water.^[26] East Midlands Trains reported that severe flooding from the River Sheaf and Porter Brook was affecting Sheffield station, with services delayed or cancelled as a result.^[25] Bus services across the city were also suspended as the flooding peaked during the evening rush hour, stranding thousands of people. Flooding was additionally reported in Sheffield City Centre, Bradway, Intake, Meersbrook, Nether Edge and Woodseats amongst other districts.^[27]

The storm continued to intensify over the North Sea, tracking toward Norway. The island of Heligoland and the Alte Weser lighthouse on the German coast recorded gusts of 107 km/h, while the Lindesnes Lighthouse in Norway recorded the highest wind speed at 154 km/h.^[28] A truck driver in Hamburg suffered injuries after his truck was hit by a shipping container.^[29]

Storm Callum

Callum
Area affected	Ireland, United Kingdom
Date of impact	10–13 October
Maximum wind gust	76 mph (122 km/h)
Lowest pressure	938 hPa (27.7 inHg)[30]
Fatalities	2
Damage	Severe flooding in Wales as well as uprooting trees

On 10 October, a tropical depression to the south of Spain organised into Storm Callum. Callum moved further northeastward while strengthening in particularly favourable conditions along with low wind shear. The system then underwent explosive cyclogenesis, as it was forced toward the United Kingdom by a jet stream.^[31] On October 11, Callum began to show signs of an eye as it reached its' peak intensity on approach to Cardiff, Wales. Only then did it encounter colder waters and the low-level eye was exposed to westerly wind shear, which had an adverse effect on Callum before it made impact on land. The system then brought intense winds with speeds of up to 76 mph (122 km/h) to parts of northern England, along with torrential rains to parts of Wales with 95.6 mm (3.76 in) recorded in Libanus but overall only made a minimal impact on land.^[32]Unexpected warm weather was reported soon after, with Donna Nook in Lincolnshire reaching 26.5 degrees Celsius in the afternoon.^[33] At 21:00 UTC, colder water surface temperatures and high vertical wind shear affected Callum, and the system soon transitioned into an extratropical cyclone.

As of 13 October 2018, the storm has caused two indirect fatalities; a 33 year old man and a 35 year old woman are said to have encountered difficulties in the Penarth Marina. The storm has caused one direct fatality; a person died after a landslide in Cwmduad. ^[34]

Ex-Hurricane Leslie

Leslie
Area affected	Portugal, Spain
Date of impact	13 October–present
Maximum wind gust	110 mph (180 km/h), Figueira da Foz, Portugal[35]
Lowest pressure	984 hPa (29.1 inHg) (while extratropical)
Fatalities	None
Power outages	None
Damage	Unknown

Hurricane Leslie was one of the longest-lived Atlantic hurricanes on record. A large, long-lived, and erratic tropical cyclone, Leslie was the twelfth named storm and sixth hurricane of the 2018 Atlantic hurricane season.