Consecutive Extratropical Cyclones Impacting the Iberian Peninsula: A Comprehensive Analysis of the 2026 Winter Season

North Atlantic extratropical cyclones propagate towards Northern Europe and are one of the major natural hazards in mid-latitudes. The 2026 winter season witnessed an unprecedented number of named storms in southwestern Europe, resulting in fatalities and significant adverse impacts across the Iberian Peninsula. While windstorm Kristin was the most impactful event, featuring record-breaking observed wind gusts exceeding 200 km/h and disrupted power grid for weeks in Portugal among other damages, the sequence of subsequent cyclones throughout February, leading to saturated soils that resulted in severe flooding, exacerbated the disruption of critical infrastructure and transport networks.

As countries in southwestern Europe are not frequently affected by severe windstorms, a comprehensive assessment of the large-scale synoptic evolution and of the dynamical mechanisms that forced the unusual cyclone explosive development and sting jet associated with windstorm Kristin (27–28 January 2026) is presented, together with a description of the associated meteorological and socioeconomic adverse impacts. The study also considers the consecutive extratropical cyclones and their impact on the hydrological cycle of mainland Portugal. For this purpose, an objective lagrangean method, which identifies and follows individual lows, is applied for the assessment of the cyclone tracks and lifetime characteristics, which is complemented by the analysis of several thermohydrodynamical ERA5 reanalysis fields during the lifetime of the cyclones. A climatological analysis for the extended winter (October to April) on the period 1931-2026 is also performed, putting the 2026 winter season into perspective.

Recent studies document that windstorms affecting the Iberian Peninsula may have different characteristics and underlying mechanisms; they are not rare events, and their frequency of occurrence undergoes strong multidecadal variability. Research also highlights the complexity of rainfall patterns, and the need for disentangling natural variability from long-term trends in the region. By presenting other historical extreme winter seasons and high-impact events, this analysis will discuss how rare this season was and propose measures for improving awareness and preparedness, at the local scale, for high-impact climate events occurring in Portugal. This research is performed in the framework of project DouroRisk - prevention and mitigation of natural hazards at the local scale.