Storm Alex Explained

Storm Alex
Fatalities:16 fatalities
Lowest Pressure:969
Power Outages:115,000
Gust:116mph at Belle-Île, France
Areas Affected:United Kingdom, Spain, Portugal, France, Italy, Austria, Poland, Czech Republic
Partof:the 2020–21 European windstorm season

Storm Alex was a powerful early-season extratropical cyclone that was particularly notable for its extreme flooding around the Mediterranean. Alex caused widespread wind and flooding damage across Europe, and at least 16 fatalities, with one more 1 person missing. Alex was the first named storm in the 2020–21 European windstorm season.

Originally, a minor low-pressure system to the south west of Greenland late on 27 September.[1] This pressure system tracked south eastwards, experiencing the Fujiwhara effect and then undergoing explosive cyclogenesis before making landfall in Brittany on 1 October. It was named by AEMET and Météo-France on 30 September, with Red warnings being issued for wind for parts of Northern France from 16:00 CET on 1 October.[2]

The storm led to advection of Mediterranean air northwards where it interacted with the coastal topography producing an extremely heavy rainfall in southeast France, known as a "Mediterranean Episode". This brought record breaking flooding and devastation to many areas in the region.[3]

The flooding in the south of France was purportedly the worst for at least 120 years, when records began.[4]

Preparations and impact

United Kingdom

Many warnings were issued for the storm by UK Met Office. The first being issued for 30 September for heavy rain across south west Scotland. This was a yellow warning, stating the possibility of localised flooding.[5] Further warnings were issued in the following days. Daily rainfall records were broken for many places. The highest fall reported as of 21:00 BST, the Met Office reported the maximum rainfall total to be at Liss, Hampshire, with the maximum gust of 71mph being recorded at Berry Head, Devon.[6]

Warnings

Warning severity Event Date Areas affected
Rain 3 October North Wales, South East Wales, South West England
Rain 3 October North East Scotland
Rain and Wind 2 October South West England
Rain and Wind 3 October South Wales, Southern England
Rain 3 October South East England

France

Departments in the south of France were particularly badly affected, with record breaking flooding and landslides. At least 5 people died.[7]

See also

External links

Notes and References

  1. News: Sun, 27 Sep 2020. 9 October 2020 . Wetterzentrale.de . 27 September 2020.
  2. fr. Météo-France. VigiMeteoFrance. 1311682638915276802. 1 dpt en #vigilanceRouge ; 8 dpts en #vigilanceOrange . 1 October 2020. 3 October 2020.
  3. WMO . 1313443439141359616 . 6 October 2020 . 500 mm of rain fell in southern France on Fri-Sat during a "Mediterranean episode" triggered by #StormAlex. .
  4. Web site: 2 missing after worst rainfall in 120 years triggers flash flooding in southern France. 5 October 2020. The Watchers. 21 September 2020 .
  5. Met Office. metoffice. 1311046302822793216. Yellow Warning issued Rain across parts of southwest Scotland Wednesday 0300-1200 Latest info Stay #WeatherAware . 30 September 2020. 9 October 2020.
  6. Met Office. metoffice. 1312127212418723840. Here are the UK top #rainfall totals and #wind gusts from #StormAlex Today's warning has now expired as Alex pulls away. However, further #wet and #windy weather is expected overnight and through much of the #weekend Stay #WeatherAware Warning . 2 October 2020. 3 October 2020.
  7. News: 4 October 2020. Storm Alex: Floods and landslides hit France and Italy. BBC News. 5 October 2020.