STORM FRANCIS - 24th/25th August

The UK Met Office named Storm Francis on Monday the 24th August 2020. Another rapidly deepening Atlantic low-pressure system, less than a week after Storm Ellen, was forecast to cross Ireland and the UK on Tuesday the 25th August, exactly 34 years to the day since Ex Hurricane Charlie hit Ireland (see below for comparison). The first affects from Storm Francis were to be felt in the Southwest of Ireland on the evening of Monday the 24th, with the low pressure centre crossing the country through the day on Tuesday the 25th. The low centre was then forecast to continue moving east north-eastwards across the North of England and into the North Sea in the early hours of Wednesday the 26th. Status yellow wind warnings, along with yellow and orange rainfall warnings were issued for the Island of Ireland.

In a similar setup to the development of the previous named storm four days earlier, Storm Ellen, a low pressure system associated with tough already in place in the mid-Atlantic interacted with an area of sub-tropical moisture enriched energy moving up from southwest (although this time not previously a tropical storm). The interaction with the left exit of the Jetstream associated with the tough in the mid-Atlantic again rapidly intensified the surface Low-pressure system, Storm Francis, which formed to the south of the parent low as it moved towards Ireland on Monday the 24th. However, this time Storm Francis merged fully with the parent low and became the dominant low-pressure centre. As such, Storm Frances was not steered by the parent low as it approached the Southwest of Ireland late on the 24th, resulting in Storm Francis taking a different path to Ellen, moving directly over the country along a line between Galway and Louth in an east-northeast direction with a minimum central pressure of 979 hPa.

Storm Francis was the ninth named storm of the 2019-20 season (the sixth on the official list of storm names by Met Éireann, the UK Met Office or KNMI). The first named Storm of the season, Lorenzo was an ex tropical system named by The National Hurricane Centre in the US and affected Ireland on the 3rd and 4th October 2019. Storm Atiyah, named by Met Eireann affected Ireland on the 8th and 9th of December 2019. A low-pressure system associated with Storm Elsa, named by the Portuguese weather service, affected Ireland on the 18th December 2019. Storm Brendan, also named by Met Eireann affected Ireland on the 13th January 2020. Storm Ciara, affected Ireland on the 9th and 10th of February 2020 and was named by the UK Met Office. Storm Dennis, also named by The UK Met Office affected Ireland on the 15th and 16th of February 2020. Storm Jorge, named by AEMET, the Spanish national meteorological service, was the 7th named storm of the season and affected Ireland on the 29th February 2020. Storm Ellen, named by Met Eireann, which affected Ireland on 19th and 20th August was the eight named storm of the season.

6 and 12 hour rainfall totals that reached warning criteria for Storm Francis

Heavy localised downpours on Tuesday associated with Storm Francis combined with overnight accumulations on
already saturated ground led to flash flooding in places. Heavy rainfall on already elevated river levels caused some
rivers to burst their banks, blocking roads in places.

  • Bantry in west Cork up to 50 businesses incurred flood damage overnight. The local main drainage scheme
    was unable to cope with up to 25mm of rain falling in a two hour period.
  • Flooding also occurred at Dunmanway, Rosscarbery, Connonagh, Clonakilty, Drimoleague, Leap, Ballydehob,
    Passage West and Youghal.
  • Fallen trees and local flooding blocked roads in counties Clare, Kerry, Wexford, Cork, Kilkenny, Laois,
    Tipperary and Meath.
  • Electricity outages left hundreds of premises without power, with Cork, Limerick, Tipperary and Galway
    worst affected.


Full report <<here>>