European Windstorm Isha (Iris) Tracks Across UK

Hurricane-force gusts recorded in the U.K. as Storm Isha made landfall

The United Kingdom Met Office (U.K. Met) named Storm Isha - also named Iris, according to the Free University of Berlin - on Jan. 19. This is the ninth named storm of the 2023-2024 European Windstorm Season.

CoreLogic® Hazard HQ Command Central™ has released an initial insured loss estimate range of 100 million pounds to 250 million pounds (EUR 117 million - EUR 293 million) based on preliminary wind observation data. This estimate includes building, contents, and business interruption losses resulting from only the wind damage to residential, commercial, industrial, and agricultural property in the U.K.

CoreLogic will update this loss estimate once the U.K. Met provides validated wind observation data. At that time, additional modeled loss guidance will be available on our Client Resource Center (CRC).

Enormous Wind Footprint Covers the UK

Isha's wind footprint primarily affected the U.K. and Ireland. This storm is notable for its reach; it covered the majority of the British Isles with relatively high gusts, including recorded wind speeds greater than 90 mph in select locations.

Isha formed off the east coast of the U.S. on Jan. 19 and was propelled rapidly across the Atlantic Ocean by a strong jet stream. By 6:00 p.m. UTC on Sunday, Jan. 21, the central low-pressure center (approximately 955 millibars) was located about 500 kilometers (310 miles) north of Ireland and strong winds began to move overlandin western Ireland.

From early Sunday evening and into the night, Isha's central low continued to track northeast, moving a few hundred kilometers north of Scotland. As it traveled, it brought high wind gusts across a vast swath of the U.K., spreading initially from the far north of Scotland and then moving to southeast England. Weather stations in Capel Curig, Wales and Brizlee Wood, Northumberland recorded gusts of 90 mph and 99 mph, respectively.

During the early hours of Monday, Jan. 22, as the central low moved further to the northeast, gusts affected the coastal regions of Belgium, the Netherlands, and Denmark.

By 9:00 a.m. UTC on Monday, the central low was located west of Norway, and due to the large wind field, it led to high wind speeds in the Baltic Sea region. As Isha continued to track northeast over the day, it led to further strong gusts in Norway before beginning to die out by the end of Monday.

Storm Isha led to significant infrastructure disruption across Ireland, the U.K., the Netherlands, Norway, and the coastal areas of the Baltic Sea. Airline companies canceled or altered hundreds of commercial flights across Western Europe. Over 350,000 properties suffered power outages in the U.K., and over 200,000 properties experienced power outages in Ireland. Large amounts of rainfall accompanied the storm, making it the wettest Jan. 21 on record in the U.K. The intense precipitation added to the already-saturated ground, leading to localized flooding in some areas of northeast Scotland.

A Very Active European Windstorm Season

The 2023-2024 European windstorm season has been relatively active to date. On Jan. 22, shortly after Isha, Storm Jocelyn (also named Jikta by the Free University of Berlin) became the 10th event named by Met Éireann. Unlike Isha, Jocelyn reached maturity prior to arriving in Europe. Its track was located further north, leading to lower gusts and associated damage. The impact of Jocelyn could exacerbate the recovery efforts from Storm Isha.

The European Meteorological Network Western Group began naming storms in 2015, and the 2015-2016 season marks the current maximum number of 11 named storms. The likelihood of 2023-2024 exceeding this number remains high.

The high activity of the current season is due to the position of a relatively strong jet stream. However, this season's activity is less remarkable relative to seasons before 2015-2016, when naming began.

CoreLogic's Eurowind™ Model's 63-year-long historical storm catalog shows that the number of impactful storms is subject to natural variability. Secular changes in rates over that period are hard to detect as they are small compared to this uncertainty.

According to the latest scientific studies, climate change may lead to a shift in storm tracks, resulting in small increases in the rate of damaging European windstorms over the U.K. However, model uncertainty is very high compared to projected loss impacts. On a seasonal basis, natural variability will continue to be the main source of loss uncertainty.

CoreLogic Hazard HQ Command Central™ will update the modeled insured loss estimate and provide modeled loss guidance once more data is available from the U.K. Met.

Contact: Please email [email protected]with questions about Storm Isha or any CoreLogic event response notifications. Visit www.hazardhq.com for updates and information on catastrophes across the globe.

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