VIRTUAL MEETING | How much rain?

SPEAKER | Mark McCarthy, National Climate Information Centre, Met Office

ABSTRACT | On 3rd October 2020 widespread persistent rainfall across most of the country resulted in a provisional estimated UK average of 31.7 mm. This statistic captured news reports at the time as being the wettest day for the UK on record and enough rain by volume to fill Loch Ness (7.6 km3). Comparably extreme wet days for the UK also occurred during storms Ciara and Dennis in February 2020. In a dataset of UK daily rainfall since 1891 there are only 40 days (less than 0.1%) where the UK average rainfall has exceeded 20 mm, and remarkably three of those have occurred in 2020, with storm Bella in December also getting very close.

But what does a UK average rainfall value mean, and how is it calculated? In this talk I will discuss how these statistics are generated, how robust they are, their limitations, and how they fit into the family of UK climate monitoring datasets we produce at the Met Office. I will also discuss how the rainfall events of 2020 can be viewed in the context of past, present and future climate variability and change.

The Royal Meteorological Society has a number of local centres across the UK, where meetings are held throughout the year. The South East Local Centre are currently hosting monthly meetings which can be attended in person or virtually. For further information on the local centre, upcoming events or to be added to the mailing list, please contact [email protected].

DISCLAIMER | Although this meeting was hosted by The Royal Meteorological Society, the work shared is that of the speakers and the views and comments of this meeting do not reflect the views and opinions of the Society