Comparisons With 1940 & 1965
By Paul Homewood
Storms Desmond, Eva and Frank certainly brought an awful lot of rain to some parts of the country last month. But what is just as remarkable is how small an area was affected by them, something borne out by the daily data from the England & Wales Precipitation Series.
As this data is only available from 1931, we cannot make comparisons with some of the wettest months on record, such as Dec 1876, Dec 1914 or Nov 1852. But we can compare with Nov 1940, the 3rd wettest November, and Dec 1965, 8th wettest. Both months recorded much more rainfall than last month.
We can see that there were five days with more rainfall in 1940 than the wettest day last month, and four were considerably wetter.
The big difference was that the rainfall in 1940 was distributed across most, if not all, of the country, as the Met Office Monthly Report indicates:
In contrast, because of the way the jet stream was set up, depression after depression targeted in on the same part of the country, the North West, for the whole of the month. To make matters worse, Storms like Desmond tended to get stuck over the same area, instead of quickly passing through.
Because this area is mainly upland/mountainous, the rainfall figures recorded were naturally higher than would have been the case elsewhere in the country.
One other difference worth noting is that there was very little rainfall in the last 10 days of Nov 1940, whereas it was fairly continuous all last month.
Again, in 1965, we find heavier days of rainfall than last month.
As with 1940, we find that the rainfall in 1965 was widely spread across the country.
It has been claimed that a warmer atmosphere, means more moisture and therefore more rain. But the evidence from 1940 and 1965 does not support this theory.
Much more rain fell, albeit over a wider area, in those years, both in the month as a whole, and on the wettest days.