Met Office’s February Storms Misdirection

By Paul Homewood

The Met Office are up to their tricks again!

https://blog.metoffice.gov.uk/2020/03/04/record-breaking-rainfall/

Their graph seems to suggest that Storm Dennis and Ciara are unprecedented in the 1981-2010 period.

For a start, they claim this is the UK daily total, but they don’t publish this data, so it cannot be checked. (So much for transparency!!)

But we can reconstruct them from the England & Wales Precipitation series, which is after all where the rain mostly fell and where the floods most affected.

Dennis, Jorge and Ciara recorded 27.87, 16.44 and 13.55mm of rain respectively, averaged across England & Wales. The chart below plots all days above 13mm in England & Wales since 1931. (Note that these are only in winter months).

https://www.metoffice.gov.uk/hadobs/hadukp/data/download.html

Dennis is 4th on the list, well down on the 33.2mm recorded in December 1960. Another way of looking at it is Dennis is the median of the top seven wettest days, in other words a once in a decade type event.

Jorge and Ciara barely register at all, ranking 55th and 151st on the list.

However, we cannot cherry pick simply by showing only winter days. Autumn months also experience storms and floods, and when we include those months as well, we find that Dennis gets relegated to 8th place.

In all there are 434 days with more than 13mm of rain, an average of five a year.

The Met Office graph therefore gives a grossly misleading impression of the three storms last month.

The Met Office article then goes on to make the usual claims about “wetter winters”, but it is clear that the country has seen similarly wet winters as long ago as the 19thC. Just as now, they were the result of “weather” not “climate”.

It is worth bearing in mind, by the way, that scientists now believe winter rainfall was underestimated prior to the 1870s, because of undercatch of snow.

Even the outlier of the 2013/14 winter is not quite as unprecedented as it appears. The three month period of Nov 1929 to Jan 1930 was actually 10% wetter. November to January, of course, is not a season, so as far as the Met Office is concerned, it does not exist!