page_title: 2017–18 European windstorm season
section_title: Storm Fionn
hierarchical_section_title: 2017–18 European windstorm season / Storms / Storm Fionn
caption_attribution_description: English: Storm Fionn of the 2017–18 UK and Ireland windstorm season on 16 January 2018.
context_page_description: The 2017–18 European windstorm season was the third instance of seasonal European windstorm naming. France, Spain and Portugal took part in winter storm naming for the first time this season.
  The season started on 12 September 2017 with the formation of Storm Aileen. It was subsequently marked by many high-impact storms which caused severe loss of life and widespread damage, including Ophelia, Eleanor, David and Emma. The season concluded on 17 June 2018 with the dissipation of off-season Storm Hector.
context_section_description: On 16 January Met Éireann issued orange marine weather warnings for wind to storm force from Roches Point to Slyne Head to Malin Head, along with orange national weather warnings for Donegal, Galway, Leitrim, Mayo, Sligo, Clare, Cork and Kerry for 16–17 January, so naming storm Fionn. This system, also called Evi by the FUB, was meteorologically speaking a very deep and large Icelandic low that bottomed out at a central pressure of 935 hPa and dominated the weather in the North Atlantic and Northern Europe for several days in the middle of January 2018. This low had a large and intense wind field on its southern flank, fuelling a strong jetstream that steered the less deep but much more catastrophic Cyclone David into the UK and Ireland and Central Europe on 18 January. After the arrival of David, Fionn weakened and David became the more dominant low, leading to the decay and dissipation of Fionn.
  As Fionn neared Ireland, it brought heavy winds to Donegal, Sligo, Mayo, Clare, Leitrim and Cork.
  On 16 January the Met Office sent out a clarifying tweet that Fionn was only expected to bring strong winds to western Ireland, with impacts to the UK to be expected to be below their warning thresholds. In the tweet they pointed to a separate weather system to affect the UK on 17–18 January, later named David by MeteoFrance, this name was reciprocally adopted by the Met Office and Met Eireann. The low David was named Friederike by the Free University of Berlin, with the name Georgina at that time remaining unused.
  Met Éireann's decision to name Fionn was met with some criticism from some meteorologists, Liam Dutton tweeted that he thought the warning did not strictly accompany a cyclonic area of low pressure, but a "squeeze of isobars" circulating a low hundreds of kilometres distant in the region of the Faroes, stating that it "needed no more than a standard weather warning". He highlighted the difference in criteria for naming storms employed by the Met Office and Met Éireann (the UK Met Office uses an impact-based criteria, based on the level of expected impacts the weather will bring, whereas the Irish Met Éireann uses fixed numerical criteria, meaning a storm will be named when mean wind speeds are likely to occur, between 65 and 80 km/h [40 and 50 mph] and/or gusts between 110 and 130 km/h [68 and 81 mph]).
  Evelyn Cusack of Met Éireann said that she understood Dutton's point, stating that his criticisms were well made. She reiterated that the orange warning issued by Met Éireann fulfilled their criteria for naming the storm, producing severe winds, coastal flooding and high waves on the Irish coast, even if the centre of circulation was distant.
caption: Storm Fionn west of Ireland on 16 January
exif: {}