Article taken from Met Office blog: 27th August 2024
The 2023/24 storm season, which runs from 1 September 2023 through to 31 August 2024 will go down as a stormy period in most people’s memories. From Storm Agnes in September 2023 through to Storm Lilian in August 2024, the UK has had its most number of named storms since the system was launched in 2015, with 12 named systems in the period.
Met Office Scientist Emily Carlisle examines the changing weather in the UK. She said: “The UK’s storm season is highly variable, and minor changes in meteorological conditions are able to influence the severity of impacts we experience in the UK. This variability can even be noted in the last two years, with 12 named storms in the most recent year, but just two storms named by the group in the 2022/23 season.
“What we’ve observed through much of the last 12 months are frequent periods of the jet stream either being directed towards the UK or to the south of the UK. This has helped to develop and direct low pressure systems to our shores which bring us the strong winds and rain that can influence the decision to name storms.”
A total of 12 storms were named in the most recent storm season by the Met Office group, which also includes Met Eireann and KNMI.
Image: Met Office
Agnes (27-28 September 2023) – The first named storm of the season was strengthened by Ex-Tropical Storm Ophelia and brought some strong winds and heavy rain. An 84mph gust at Capel Curig was the equal-highest September gust on record for Wales.
Babet (18-21 October 2023) – Babet was chiefly a rainfall event, with two red warnings for rain issued by the Met Office, with associated gusty winds. Eastern parts of Scotland had the highest rainfall totals, with 150-200mm of rain falling for many. The county of Angus had its wettest day on record, by a wide margin, on 19 October 2023 in a series from 1891.
Ciarán (1-2 November 2023) – Storm Ciarán was an exceptionally severe storm, but its path led to the worst of its impacts being felt in the Channel Islands and France. The strongest winds from Storm Ciarán were shifted to the south of the UK, with northern France and the Channel Islands having wind speeds comparable to the ‘Great Storm’ of 1987. UK wind gusts peaked at 78mph, but some stations in the north of France exceeded 100mph, and a tornado reportedly affected eastern parts of Jersey.
Debi (13 November 2023) – Named by Met Eireann, Debi had the most impacts for the Republic of Ireland, where a red weather warning was issued. For the UK, it was a notable rather than exceptional system, with some gusty winds and over 100mm of rain across upland areas of northwest England.
Elin (9 December 2023) and Fergus (10 December 2023) – Elin and Fergus arrived in consecutive days in December and were named by Met Eireann. They were a continuation of a wet and windy start to meteorological winter. Exposed UK coasts recorded gusts in excess of 70mph, with associated rain falling on saturated ground and causing flooding issues for many.
Gerrit (27-28 December 2023) – The post-Christmas period brought further winds and heavy rain for the UK, with Wales, northwest England and Scotland the worst affected. A peak gust of 89mph was recorded in Shetland, with wind in excess of 80mph recorded for some sites in the north and a tornado reported in Greater Manchester.
Henk (2 January 2024) – Winds and rain were again the hazards for Henk, with significant flooding issues, travel and power disruption for many. A wind gust of 81mph was recorded at Exeter Airport, but a very exposed site on the Isle of Wight recorded 94mph. Coupled with much of the southwest and south Wales receiving between 50 and 100mm of rain, these combined for an impactful start to the year’s weather.
Isha (21-22 January 2024) and Jocelyn (23-24 January 2024) – Isha and Jocelyn arrived in quick succession as the ninth and tenth storms of the season, chiefly influenced by a powerful jet stream. Isha was more impactful for the UK, in what was the most significant major wind storm since Eunice on 18 February 2022. Jocelyn was less severe for the UK, but brought more pronounced impacts for the Republic of Ireland.
Kathleen (6-7 April 2024) – Kathleen was an unseasonably deep area of low pressure for the time of year, bringing gusty winds for many in the north and west. Kathleen set new April gust speed records at several stations in Scotland and Northern Ireland, with travel disruption and power outages for some.
Lilian (22-23 August 2024) – Lilian in the second half of August meant that a record number of storms were named since the creation of the project in 2015. Lilian brought strong winds and heavy rain to northern England and Wales, as well as parts of Scotland, with a provisional maximum gust of 73mph.
Storms are named to raise awareness of severe weather before it hits so everyone can stay safe. Post-storm surveys show the effectiveness of naming storms to raise awareness, with 97% of those within the amber and red warning areas for Storm Babet being aware of the warnings, and 89% of these taking action as a result.
Storms are named by Met Office, Met Eireann or KNMI when they are deemed to have the potential to cause ‘medium’ or ‘high’ impacts in one of the countries of the group. This would typically mean when an amber or red warning is expected to be issued at some point during the event.
With only the short dataset of named storms since 2015, it’s not possible to detect trends in storms at this range, so it’s important to look further into the Met Office archives.
Met Office’s Emily Carlisle explained: “The UK has a history of impactful storms stretching back hundreds of years, long before the introduction of named storms in 2015.
“One thing that is clear from observations is that there’s big variability year-to-year in the number and intensity of storms that impact the UK. In our observational records, it’s hard to detect any trend one way or the other in terms of number and intensity of low-pressure systems that cross the UK.
“While our climate overall is getting wetter, there are no compelling trends in increasing storminess in recent decades. Recent stormy seasons – such as that of 2013-2014, before the storm naming system was introduced – clearly illustrate the fundamental problem with drawing conclusions from a simple count of the number of named storms.”
Most climate projections indicate that winter windstorms will increase slightly in number and intensity over the UK as a result of climate change. However, there is medium rather than high confidence in this projection because some climate models indicate differently. Year-to-year variability in storm frequency and intensity will also continue to be a major factor in the future climate. We can be confident that the coastal impacts of windstorms, from storm surges and high waves, will worsen as the sea level rises.
Find full scientific reports for each of the season’s named storms in the Met Office’s UK Storm Centre.
Find out the latest storm names for the 2024/25 season from the Met Office on 29 August 2024.
