By Anders Lorenzen

If you live in the UK you may feel that the winter season of 2023/24 was one big rain cloud. 

Now a group of scientists have concluded that the winter season on the British Isles was exceptionally wet.

Analysis carried out by scientists from the UK, Ireland, the Netherlands, Sweden and Germany and published in the study ‘Autumn and Winter storms over UK and Ireland are becoming wetter due to climate change,’ as the title suggests this year’s very wet winter – measured from October to March is part of an ongoing trend, and that climate change is making the region wetter.

What is happening?

The very wet winter season was a result of several powerful storms primarily dictated by the position and strength of the jet stream, a band of strong westerly winds high up in the atmosphere driven by temperature differences between the equator and the poles. The position and strength of the jet stream influence how many low-pressure systems are directed towards Ireland and the UK, with the strength also defining whether these low-pressure systems intensify enough to become Atlantic Storms.

The researchers analysed this using data from the wind-based Storm Severity Index (SSI) which encompassed the area of the UK and Ireland and investigated how big a role climate change played.

The winter season was one of the wettest Ocobert-March periods on record for the UK and the third on record for Ireland. 

Is it driven by climate change?

The scientists concluded that climate change played a major role as the average precipitation on stormy days is observed to have become approximately 30% more intense, compared to a 1.2 degrees C cooler pre-industrial climate and is broadly in line with climate models which indicates that average precipitation on stormy days increased by about 20% due to human-induced climate change.

The observed precipitation across the time period trended strongly, with a magnitude increase of about 25%. Climate models utilised in this study broadly agree on the direction of the change, and the combination of observation and model results indicates an increase in the magnitude of 6% to 25%. 

The wet winter in the UK has continued well into 2024 making Spring in many parts of the country a wash-out.