'Storm Éowyn's winds turn everyday objects into missiles’

Two rare red weather warnings, meaning there is a danger to life, are in place for Northern Ireland and Scotland as Storm Éowyn batters the UK and Ireland. 

Meteorologists from the University of Reading offer expert comments on Storm Éowyn. To arrange interviews, contact the University of Reading Press Office on 0118 378 5757 or email pressoffice@reading.ac.uk. 

Read expert comments posted yesterday (Thu, 24 Jan): Storm Éowyn 'rapidly intensifying' as it approaches UK

Professor Hannah Cloke, Professor of Hydrology at the University of Reading, said: “Weather warnings are vital, alerting us before disaster strikes. The damage we're seeing in red warning areas shows their importance. Storms tear roofs from buildings and transform everyday objects into dangerous missiles. But even yellow and amber warnings demand serious attention - severe weather effects can be extremely localised and unpredictable. For those who've only had light winds and sunshine so far - don't be complacent. With alerts continuing through to Sunday, conditions can change rapidly. What starts as a calm morning in your garden can escalate quickly. These warnings aren't overcautious bureaucracy - they're essential protection for our communities. Take precautions while alerts remain active, regardless of your local conditions. Every warning level matters."

Professor Andrew Charlton-Perez, Professor of Meteorology at the University of Reading, said: “The level of danger from Storm Eowyn is already quite clear given the widespread disruption in Ireland. It’s therefore very sensible for everyone in the affected areas to avoid travelling if possible and so closing schools and shutting down rail services is a key part of the response.

"It will always be hard to know what the consequences of any weather warning will be because there is no controlled experiment to test what would have happened had the warning not been issued. It’s impossible to know if deaths were avoided because of the warning. One way to test the impact on public awareness of the coming hazard is through the number of news stories and social media posts which mention the storm and the weather warning. It’s also possible after the event to compare data that shows how, for example, traffic patterns compare today to patterns over the last month. If people are travelling less, then it’s a good sign that the warning has had its intended effect. The number of schools that have been closed is also a good indication that public bodies are responding appropriately to the warning."

Professor Helen Dacre, Professor of Meteorology at the University of Reading said: “Red alerts issued by the Met Office are extremely rare, with only one or two being issued each year. These alerts signal severe weather conditions that pose a serious danger to life and are likely to cause significant disruption. While it is difficult to determine objectively if a red alert has "worked," as there is no control scenario where people do not receive the alert, the Met Office conducts surveys following such events to gauge public response. These surveys help assess how many people took action after receiving the red alert and how useful they found the warning. The national severe weather warning system (NSWWS) was introduced in 1988 following the Great Storm of 1987, which killed 18 people after millions of tree were blown down. Events like these offer an indication of potential impacts that may have been avoided due to the introduction of widescale weather warnings. The Met Office started naming storms in 2015, which has helped with public communication. Since last year Government Emergency Alerts have also been used to warn of extreme weather.  This combination of public feedback and historical data provides valuable insights into the effectiveness of red alerts in protecting communities.”

Dr Oscar Martinez-Alvarado, Postdoctoral Research Scientist at the University of Reading, said: “It is sensible to take action following the red warning from the Met Office. These warnings are based on numerical models and tools which, while not perfect, are very advanced and are reliable at this sort of lead time. Furthermore, the storm effects are starting to be realised over Ireland, Northern Ireland and Scotland and are consistent with what was predicted.

“Éowyn is a very powerful storm, one that can be very easily classified as an explosive storm (or meteorological bomb). It has already undergone a very rapid intensification of ~52 hPa in the 24 hours previous to 18 UTC 23 Jan, according to Met Office charts, and it continued intensifying at similar rates at least for the next six hours. For reference, the threshold to describe a storm as explosive is 24 hPa in 24 hours. Given its trajectory, the most dangerous region in terms of wind hazard is the region south of its centre. Ireland and Scotland are located in this region for Éowyn and therefore will feel the most devastating effects. These effects can be minimised by following the advice regarding avoiding travel and closing schools.

“Several factors affect the development of a storm, such as where the storm forms, what are the conditions (moisture, temperature, location of the jet stream) along its path. Moisture in particular has the effect of powering storms as this moisture is condensed, forming precipitation (rain and snow) and releasing energy. While climate change alone can't be blamed for a particular storm, the fact that there is more moisture in a warmer atmosphere means that a warmer climate can sustain more powerful storms.”