Co-occurring British flood-wind events (1980-2080): Their anatomy & drivers

<p>In wintertime, infrastructure and property in NW Europe are threatened by multiple meteorological hazards, and it is increasingly apparent that these exacerbate risk by tending to co-occurring in events that last days to weeks. Impacted by Atlantic storms, Great Britain (GB) is a sentinel location for weather that later tracks into NW Europe. &#160;&#160;A recent, dramatic storm sequence (Dudley, Eunice, Franklin) demonstrated the need for a multi-hazard view by bringing a mixture of damaging and disruptive extremes including extreme winds and flooding over 7-10 days in Feb 2022.</p> <p>This work uses a stakeholder inspired, event-based approach to jointly consider these two hazards.&#160; A wind event set (<em>n</em><em> </em>= 3,426) is created from the 12km regional UK Climate projections (1981-1999, 2061-2079) to match previously created high-flow events (Griffin et al, 2023). Then, the two hazards&#8217; time-series are merged using windows up to a maximum size (&#916;t = 1-180 days) positioned to maximize the size of the largest events&#8217; impact. The benefits and limitations of this methodology are discussed, anatomy of storm sequences (&#916;t = 21 days) discussed, and potential drivers of co-occurrence in the multi-hazard sequences (e.g. jet stream position/strength) examined.</p>