Saturday 4 November 2023

Storms and more storms

Barometer in Bournemouth during Storm Ciarán

We didn't use to name storms in Europe consistently. Severe weather systems that caused disruptions in Europe sometimes were christened after the person who spotted them, after the saint’s day of their occurrence, or by the public. However, it is only recently that Europe has established formal naming systems to reduce confusion. With the advent of social media, the use of different names for the same systems proliferated rapidly online causing great confusion. 

After a deadly extratropical cyclone lashed the Scandinavian region in 2013 but was dubbed the October Storm, St Jude Storm, and Storms Christian, Simone, and Allan by different countries and sources, Denmark, Sweden, and Norway’s meteorological services began the practice of jointly naming storms. 

The UK Met Office and Ireland’s Met Éireann piloted their naming project in 2015, and France, Spain and Portugal joined thereafter in December. Belgium and the Netherlands followed. 

Only storms that prompt an Amber “be prepared” or Red “take action” warning are christened with their own title under this system, and the impact of wind, rain and snow are taken into account. Naming storms has been proven to raise awareness of severe weather, crucially prompting people to take action to prevent harm to themselves or their property.

Each year, 21 names are compiled from suggestions by the public—Storm Abigail was the first to be named under this system on 10 November 2015—and the gender of the first storm alternates at the beginning of each season which starts in September. Each new storm is also named alphabetically, but ‘Q’, ‘U’, ‘X’, ‘Y’ and ‘Z’ are excluded since few names begin with those letters. 

Weather buffs in Germany can submit name suggestions for storms for a fee. The Institute for Meteorology of the Free University in Berlin sells storm-naming rights to members of the global public via their ‘Adopt a Vortex’ programme. A high-pressure area costs €390, whereas a low-pressure area, which lasts less time and therefore offers less exposure, costs €260. Storms are named alphabetically throughout the year from A to Z and are published on official weather maps for wider use.

Since 2017, Europe has been divided into five zones, within which the weather services collaborate to jointly name the latest phenomenon. The World Meteorological Organization is the main authority for the world but delegates the choice of names, which must alternate between masculine and feminine, to the five regional bodies in Europe. WMO only names a storm if it exceeds wind speeds of 119 km/h and is accompanied by torrential rain. 

It all depends on which country the storm hits first. In the case of Ciaran, which was due to hit the northwestern quarter of France on Wednesday, November 1, the group containing Ireland, the United Kingdom and the Netherlands chose this name. Domingos was named by Spain's meteorological service. 

So what does this have to do with viticulture? Just wondering if all these severe systems will have an impact on our yield this year. 

And by the way, people have been freaking out about the extremely low pressure in these systems breaking 100 yo records.  #StormCiarán has been called a 'weather bomb', an unofficial term for a low pressure system whose central pressure falls 24 millibars in 24 hours in a process known as explosive cyclogenesis. Looking at Ciarán system the GFS model shows:

  • 984hPa 6am
  • 960hPa 6pm
  • 950hPa 6am

That is 24hPa drop in 12 hours and 34hPa in 24 hours. That shows how quickly he developed and how serious the storm became in a very short space of time. However, the strongest winds were to the South of his center away from Ireland thank goodness. 

After #Ciarán, #StormDomingos will bring strong winds, high waves and heavy rain to #France, #Spain, Portugal, and #Italy


Pressure in Fowey


Pressure in Emsworth

🌀#Domingos as seen by #Copernicus #Sentinel3🛰️ on 3 November


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