Scientists comment on Storm Eowyn, after weather warnings have been issued across the UK and Northern Ireland.
Prof Douglas Parker, Professor of Meterology, University of Leeds, said:
“We have known about these storms for more than 100 years, but we are constantly learning more about their behaviour, and our ability to forecast them gets better every year. What’s really changing is that we can localise the impacts of the storm to within tens of kilometres, even a day or two in advance. We are approaching the level of “postcode forecasting”. This means that we can give people ever more confident warnings to protect themselves and their livelihoods. It also means that we can be more confident about those places where the effects will be less severe, and business can continue as normal. Taking precautionary action costs money and by predicting exactly where the weather impacts will be, we can take action where it is really needed.
“We understand that with climate change, the severity of these storms is increasing. There is a lot we don’t still understand, but we can say with some confidence that a severe storm in our current warmer climate is likely to bring heavier rain and have more intense localised wind extremes than the equivalent storm a few decades ago. And as temperatures continue to warm, we expect those changes to get even more noticeable, because the water cycle changes exponentially with temperature.”
Prof Amanda Maycock, Professor in Climate Dynamics, University of Leeds School of Earth and Environment, said:
“One reason this storm is expected to be so impactful is because it is passing right over the UK and Ireland. Often the centres of storms, where winds are most powerful, pass over the sea and we do not feel the strongest winds on land. Currently the storm is being steered right over our heads by the jet stream and we are being barrelled down.”
Prof John Marsham, Prof of Atmospheric Science, University of Leeds, said:
“Eowyn really is a very intense storm – record breaking winds have been recorded in Ireland. Progress in forecasting mean these events no longer come as a surprise as they sometimes did in the past: some will remember Michael Fish and the infamous forecast for the Great Storm of 1987 – we now know such events are coming days in advance. Warnings such as those issued for Eowyn enable people to plan and take action – saving money and lives.”
Dr Oscar Martinez-Alvarado, senior research scientist in the Department of Meteorology, 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.”
Prof Helen Dacre, dynamical meteorology researcher, University of Reading; and Met Office Academic Partnership Joint Chair at 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.”
Prof Hannah Cloke, Professor of Hydrology, 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.”
Dr Chris White, Reader in Engineering for Extremes; and Head of the Centre for Water, Environment, Sustainability and Public Health, University of Strathclyde, said:
Is it sensible for things like schools and rail to be closed?
“Closing schools and halting rail services in Scotland is the right call today to keep everyone safe. This is more than just the high winds of a west coast hoolie blowing in. The red weather warning highlights the extreme weather that is causing unsafe travel conditions and may pose a danger to life. People should heed the emergency alert advice to stay inside where possible.
What does Scotland have in store today?
“Today will be an extraordinarily wild day across Scotland and the severity of the conditions and their potential impacts should not be underestimated. Scots are no strangers to wind, but this will be exceptional and people across the country should follow the advice to stay inside while the storm sweeps through. The likelihood of damage to property, infrastructure and power supplies is high, but people should hunker down and not attempt to inspect or repair until the alerts are lifted and the danger has passed.
Anything else of significance about this storm?
“Red weather warnings are rare and today’s highlights the high likelihood of property damage and severe impacts on transport and infrastructure across the centre of Scotland.
“As changes to our climate accelerate, we are likely to see that these rare extreme events will become more frequent and increasingly severe. Our research on predicting extreme events and their impacts, like today’s multi-hazard forecast of severe winds combined with the potential for coastal flooding from large waves, is helping to strengthen Scotland’s preparedness and infrastructure resilience in the face of these changes.”
Dr Jess Neumann, Associate Professor of Hydrology, University of Reading, said:
“As record winds batter parts of the UK and with more to come, the closure of schools, airports, rail services and the advice to avoid travel in red warning areas is absolutely the right decision.
“Red weather warnings warn the public that there is imminent danger and a risk to life.
“Do not underestimate the risk. Wind gusts are intense, unpredictable and catch people off guard – stay safe, be prepared and plan ahead.
“Severe flooding is likely and flash floods could strike fast and with little warning. Check your flood risk online at https://www.gov.uk/check-flooding and take action now if you’re in a vulnerable area.
“For those at imminent risk of flooding, act quickly. If time permits and it’s safe, turn off your gas and electricity, move valuables to higher ground, and relocate to safety.”
Dr Andy Russell, Director of the Research Centre for Environmental Change and Communities, Queen Mary University of London, said:
“It’s such a sensible idea to be proactive in response to dangerous weather warnings. We’ll never know for sure if our actions saved lives or prevented damage but when we have good predictions of high impact events we should not shy away from making decisions to keep people safe.”
Prof Joanna Faure Walker, Head of Department, UCL Department of Risk and Disaster Reduction, said:
“When considering closing of schools, it is important that the relative risk of the children and staff are considered. Is the school building safer or less safe than the alternatives? Where will the children be if not at school and is this safer? It is not just the school building itself, but the journey there that need considering. School leaders need to have detailed knowledge of their building stock and awareness of high risk areas. They will also be best placed to understand their community’s specific vulnerabilities and if particular members of the school would have additional difficulties, such as those with some disabilities. It might be particular buildings within the schools that are less or more safe than others and so specific activities should be suspended. Like snow days, water works emergencies and other short term closures, we need to ensure that head teachers or other key decision-makers have the adequate information and tools to consider the main risks and possible cascading impacts so they can make evidence-based informed decisions.
“When considering closures or restrictions to critical infrastructure including transport, it is the peak gusts as well as sustained wind speed and the design tolerances that need consideration.”
Prof Andrew Charlton-Perez, Professor of Meteorology, 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.”
Prof Hayley Fowler, Professor of Climate Change Impacts, and Director of the Centre for Climate and Environmental Resilience, Newcastle University, said:
“Another red warning for the UK, another violent wind storm accompanied by extreme rainfall and probable flooding. Our work using high-resolution climate models from the UK Met Office shows that climate change is making storms like Eowyn more frequent, with more intense wind speeds and much higher rainfall amounts. Risks are changing rapidly: we are living in a much warmer world, with temperatures breaching the 1.5 degree warming threshold in 2024 for the first time. As the climate gets warmer we can expect these storms to become even more intense, with greater damages.
“Recent storms show that society has not adapted to worsening climate conditions. Countries must build more resilient infrastructure to adapt to a more turbulent climate. This will be costly, but far less costly than doing nothing. Ultimately, only reducing greenhouse gas emissions will mitigate risks from extreme weather. But emissions are still rising year on year, committing the world to more warming and with it, more intense flooding and storm damage.”
Prof Suzanne Gray, Professor of Meteorology, University of Reading, said:
“Storm Éowyn is currently forecast to become one of the deepest storms on record in the UK, with the central pressure dropping to below 940 millibars as the storm approaches the west coast of Scotland. Pressures below 940 mb are rare for the British Isles, with only five reliably recorded occasions of pressures below 940 mb on the mainland British Isles in 200 years of reliable measurements up to 2007.
“Storm Dirk, which occurred on Christmas Eve 2013, was a recent record breaker for storm pressure. Its central pressure drop to 927 mb as it approached North West Scotland made it the deepest storm in the vicinity of the British Isles since 1886. While Storm Éowyn is not forecast to beat this record, it is certainly a storm to watch.
“Stormy weather is not unusual in the autumn and winter over the UK. It requires detailed research to attribute the strength of the impacts of any specific storm to climate change. To date, the observed trends in UK storminess have not provided a conclusive link with climate change. One reason why is it difficult to make this link is that the position and variability of UK storminess is very dependent on the position of the jet stream, which varies substantially. However, studies have shown that winter storms may become more frequent and clustered in the future, such that several storms occur one after the other. The intensity of rainfall is likely to increase but it is unclear how the overall intensity will change because of competing effects. The small number of studies that have considered the “sting jets” that can produce particularly strong localised surface winds and gusts have found an increasing likelihood that they will occur in storms.”
Dr Carola Koenig, flood and climate change expert, Brunel University of London’s Centre for Flood Risk and Resilience, said:
“With storm Éowyn making landfall, most of the UK will be affected by strong winds and heavy rain, particularly on Friday which has red weather alerts in place, mostly for northern regions.
“Residents are advised to follow MET Office advice and prepare. This includes knowing how to shut off electricity and gas, having emergency numbers to hand and having an emergency bag packed which should include required medicine, warm clothing and blankets. For further helpful advice, see Protecting property from flooding – Met Office1.”
Dr Nicholas Leach, postdoctoral researcher within the Predictability of Weather and Climate research group, University of Oxford, said:
What do we know about this storm and is it expected to be damaging?
“Éowyn is an extratropical cyclone that has formed in the North Atlantic.
“It is forecast to be a “bomb” cyclone that has intensified extremely rapidly.
“Bomb cyclones are typically the most impactful winter storms in Northern Europe. Other recent notable bomb cyclones include Eunice in 2022 and Ciaran in 2023.
“Éowyn is likely to cause potentially severe damage along the West coast of Ireland and across Northern Ireland and Western and Southern Scotland.
What does an amber or a red warning mean?
“An amber warning means that widespread disruption is expected from impacts such as:
– flying debris causing injury and may pose a danger to life;
– power cuts;
– transport infrastructure damage;
– damage to buildings, especially rooves.
“I note that the Met Office has upgraded the amber warning to red for parts of Northern Ireland and West Scotland:
– Fallen trees are very likely to cause extremely dangerous driving conditions;
– Flying debris including roof tiles causing a risk to life;
– Red weather warnings are rarely issued and it is crucial that people check for updates and stay safe – for example by avoiding travelling if at all possible.
What causes storms like these?
“Storms like Éowyn typically form along the boundaries between high and low atmospheric temperatures, in this case along a cold front in the North Atlantic.
“The cold air behind the front sinks, forcing the warm air to rise. The displacement of the warm air creates a low pressure center, drawing more air in.
“Feedbacks from air temperature and humidity gradients further fuel the intensification of the low pressure system and associated high winds and precipitation.
Is there anything unusual about this one or is it a standard winter storm?
“Éowyn looks like an archetypal extratropical winter storm based on how it has formed out of a cold front in the North Atlantic.
“However, its intensity is unusual. Its central pressure, which is often how meteorologists measure storm intensity, is forecast to drop to 940 hPa, which would rank it among the most intense storms on record in the UK. This would be the lowest pressure over the UK since 1982. It’s also worth saying that just because a storm is intense from a meteorological perspective it doesn’t mean it will be severely damaging – which also very strongly depends on where the storm tracks.
“It has undergone exceptionally rapid cyclogenesis, at around double the rate required for explosive cyclogenesis.
“The wind speeds forecast are also very unusual. Wind gusts of over 170 mph have been forecast offshore, with gusts of well over 100 mph forecast onshore along the West Coast of Ireland.
Climate change and extratropical cyclones
“Although the impacts of climate change on extratropical cyclones are still uncertain, there have been a number of recent studies that have suggested the strongest storms (such as Éowyn) may get stronger with climate change.
“In a study1 published last year led by a colleague, Shirin Ermis, we showed, using a state-of-the-art weather forecast model, that in a counterfactual warmer climate, Storm Eunice would have been significantly stronger and wetter.
“This is due to the additional humidity in the atmosphere causing increased latent heating, thus intensifying the storm more than otherwise.”
1 https://iopscience.iop.org/article/10.1088/2752-5295/ad4200
Dr Sarah Kew, Researcher at the Royal Netherlands Meteorological Institute and co-lead of World Weather Attribution, said:
“According to a recent World Weather Attribution study1, Winter and autumn storms are depositing about 20% more rainfall in the UK and Ireland due to climate change.
“The influence of climate change on storm winds is less clear. Studies have identified small increases or decreases in storm winds in the UK and Ireland using different datasets and climate models, but more research is needed.
“A warmer climate is not a good thing for the UK and Ireland. With only 1.3°C of warming, autumn and winters are significantly wetter. As temperatures rise, this effect will worsen – heavier rainfall will impact all aspects of life, from homes and farms to stormwater systems, transport networks, and football pitches.”
Dr Chris White, Reader in Engineering for Extremes; and Head of the Centre for Water, Environment, Sustainability and Public Health, University of Strathclyde, said:
“Red warnings are rare; they only get issued only when there is a high chance of impacts and a risk to life.
“Storm Éowyn is a potentially dangerous ‘multi-hazard’ event – a combination of very strong winds, heavy rain and snow – which can produce a wide range of impacts.
“The exact impacts of these types of storms are challenging to forecast, however, which makes them particularly challenging to prepare for and manage. We are in for a potentially wild day here across Scotland’s central belt.”
Dr Ambrogio Volonté, Senior Research Fellow, Department of Meteorology, University of Reading, said:
“Storm Éowyn is shaping up to be an impressive storm, rapidly intensifying as it races east across the North Atlantic. It is set to make landfall over Ireland in the early hours of Friday, before sweeping across the British Isles throughout the day. Gusts are predicted to exceed 100mph in exposed areas on Ireland’s west coast. Storm Éowyn could rival the ferocity of Storm Eunice and Storm Ciarán, both of which sadly claimed lives and left behind severe damage.
“The storm is “explosively developing,” meaning it’s intensifying at an exceptional rate. Its central air pressure is expected to plummet by over 50hPa in just 24 hours – more than twice what’s needed for meteorologists to classify it as explosive. This rapid strengthening happens when a powerful jet stream high in the atmosphere combines with a sharp contrast in temperatures and moisture at the ocean’s surface, creating the perfect conditions for the system to grow into a particularly intense and dangerous storm.
“In fact, Storm Éowyn’s structure mirrors some of the most formidable storms of recent decades, and its predicted intensity puts it firmly in the ranks of the strongest we’ve experienced. With such extreme winds on the horizon, Met Éireann and the Met Office have issued important warnings so people can appropriately prepare for widespread disruption and damage.”
Prof Liz Bentley, Chief Executive, Royal Meteorological Society, said:
What do we know about this storm and is it expected to be damaging?
“Storm Éowyn is a rapidly deepening low pressure system developing to the west of the UK and will quickly move across the UK during Friday with peak wind gusts of 80-90mph across Northern Ireland, North Wales, Northern England and Southern Scotland and some exposed locations could record 100mph gusts. These are damaging strength winds and there is a danger to life from flying debris, large waves near the coast, fallen trees and damage to building and the Met Office has issued rare red warnings.
What does a red warning mean?
“It is rare for the Met Office to issue red warnings. They are the highest level of weather warning and indicate that dangerous weather is expected and there is a danger to life. People living or travelling in the area under the red warnings are encouraged to take action to keep themselves and others safe from the impact of the severe weather, in the case of Storm Éowyn that impact is from strong winds. In addition to the risk to life there is also the likelihood of substantial disruption to travel, energy supplies and damage to building and infrastructure. People there should avoid travelling if at all possible and follow the advice of the emergency services and local authorities.
What causes storms like these?
“The jetstream, which is a band of strong winds at the top of the atmosphere around 30,000ft above the ground, provides the mechanism for storms, like Storm Éowyn, to develop. The jetstream in winter is often stronger leading to more storms forming, and its position is often closer to the UK so those developing systems are directed towards our shores.
“The current maximum speed in the jetstream is more than 250mph and data from flightradar24 highlighted that a flight BA from Las Vegas to Heathrow hit a speed of 814mph thanks to the strong tailwind in the jetstream. The subsonic speed record currently stands at 835mph, so that record could well be broken in the coming hours.
Is there anything unusual about this one or is it a standard winter storm?
“Storm Éowyn is a particularly potent storm particular because of a very active Jetstream, also the storm will be at its strongest as it crosses the UK and Ireland.”
Dr Jess Neumann, Associate Professor of Hydrology, University of Reading, said:
“Storm Éowyn is not one to underestimate – stay safe, stay prepared, and plan ahead. This storm has the potential to bring serious risks, not just to travel and property, but to your safety and wellbeing.
“Storm Éowyn is set to hit the UK hard on Friday, bringing 90mph winds, torrential rain, and potentially leaving heavy snow in its wake.
“Expect widespread travel disruption, power outages and dangerous conditions along coastlines and high wind areas. Severe flooding is likely, with heavy rain and snowmelt combining to create hazardous surface water and flash floods that could strike with little warning. Check your flood risk online at https://www.gov.uk/check-flooding and take action now if you’re in a vulnerable area.
“If you must travel, be prepared for delays. Carry spare warm clothes, blankets, bottled water, a torch, and ensure your vehicle is fuelled and well-maintained. For those at risk of flooding, act quickly. If time permits and it’s safe, turn off your gas and electricity, move valuables to higher ground, and relocate to safety.”
Prof Daniela Schmidt, Professor of Earth Sciences, University of Bristol, said:
“Climate changes is too often reduced to warming, and numbers which are small compared to the seasonal changes in temperature, giving a false sense of security.
“Climate change also changes how much vapour is in the atmosphere, how strong our storms become, how frequent they are, and how much flooding this has the potential to cause.
“We need to learn from disaster risk reduction to be better prepared for these events, and early warning is a very important part of this preparedness. We need to look out for those most vulnerable, who might not hear these warnings, do not understand them, or cannot act. And ultimately, we need to adapt and reduce our emissions as these storms, fires, droughts are just the beginning of we do not prioritise action.”
Prof Tim Palmer, Royal Society Research Professor Emeritus, University of Oxford, said:
“It may be tempting to attribute the exceptional Storm Eowyn to climate change. However, in this case, it is not straightforward. The storm has been fuelled by an exceptionally strong jet stream over the North Atlantic. However, the strong jet stream is in turn linked to the circulations over North America which have brought cold temperatures over much of the continent, with a strong gradient of temperature with sea temperatures in the Gulf of Mexico (!) and elsewhere. Whether the circulations bringing the cold air to North American have a climate change component is currently unknown. Some speculate it does, but the evidence is not clear.
“Whilst climate change is relatively simple and straightforward at the global scale, it gets complicated at the regional scale where the effects of CO2 interact with the naturally occurring dynamical patterns of climate variability. Although we have a good understanding of the basic thermodynamics of climate change – how it warms and moistens the atmosphere – our understanding of these dynamical impacts of climate change is much less good.
“It is likely that the thermodynamical effects of climate change have intensified Storm Eowyn somewhat. However, we do not know whether the potentially more important dynamical effects of climate change have exacerbated the storm or not. This is an area of ongoing research where the development of high-resolution climate models is proving vital.”
Declared interests
Dr Andy Russell: “I’m currently seconded to Parliament (I’m still free to comment on things though) and have previously worked at CCC, Defra and BEIS.”
Prof Hayley Fowler: “Member of Adaptation Committee for UK Climate Change Committee.
Assurance Review Panel for the CCRA4 Technical Report.
Member of Department of Energy Security and Net Zero Science Expert Group (E-SEG)(2021-2025).
Chair of Met Office Hadley Centre Climate Programme Science Review Group .
Co-chair of WCRP’s Global Precipitation Experiment (GPEX) WG3 Modelling and Prediction.
Member of Royal Meteorological Society Council & RMetS Strategic Planning Board.
Editor:
Chief Editor of Frontiers in Interdisciplinary Climate Studies;
Associate Editor of Climate Risk Management.
Funding: DESNZ, NERC, European Research Council, EPSRC, Environment Agency.
PhD studentships with WTW, SEPA.”
Prof Suzanne Gray: “No conflicts of interest.”
Dr Nicholas Leach: “I am employed by Climate X, a climate risk analytics start-up, in addition to my role at the University of Oxford.”
Dr Chris White: “No conflicts that would affect this.”
Dr Sarah Kew: “Sarah Kew is employed by KNMI as a civil servant to work on links between extreme weather and climate change, is a leading member of World Weather Attribution initiative, and is also funded by the EU-funded project XAIDA (eXtreme events : Artificial Intelligence for Detection and Attribution, XAIDA.eu: https://xaida.eu/) to connect climate services and stakeholders to scientific advances in climate attribution research.”
Dr Ambrogio Volonté: “No conflicts to declare.”
Dr Jess Neumann: “No conflicts to declare.”
Prof Daniela Schmidt: “No competing interests.”
Prof Tim Palmer: “No interests to declare.”
For all other experts, no reply to our request for DOIs was received.