Recent articles here have included Jit’s “The BBC’s Latest “Unreality” Check”ⁱ and Richard Drake’s “Malinformation”ⁱⁱ, so in a sense this contribution can be regarded as loosely continuing a series.

There is something of an irony in the fact that the BBC has now prominently employed Climate Disinformation Specialists to debunk claims it doesn’t like which don’t fit the climate emergency narrative, given that the BBC is no stranger to climate disinformation itself, as we will see below.

Climate change: Flooding is ‘the new reality’ in Wales

So says an articleⁱⁱⁱ appearing on the BBC website on 15^th February 2022. The story was presented as follows:

Record-breaking flooding is becoming “the new reality” for communities, according to Natural Resources Wales (NRW).

Two years after storms wreaked havoc across Wales, the environmental watchdog warned urgent action was needed to prepare for climate change.

“The need to act now to prepare for climate impacts is more pressing than ever,” it said.

Storms Chiara, Dennis and Jorge led to record rainfall in February 2020.

The BBC seems to have learned from the Guardian to link to its own articles by way of supposed evidence in support of a claim, when the link – for those who trouble to follow it – provides no such thing. Thus, the last few words, in the original article, provide an embedded link to another BBC article^iv dating back to 23^rd February 2020: “Flooding: Call for UK cash to fund flood relief in Wales”.

Nowhere does that linked article refer to or justify a claim of record rainfall in Wales in February 2020. In fact, a quick internet search shows that December 2015 was much wetter than February 2020 in Wales. However, we can do much better than a quick internet search. What follows, I’m afraid, is a detailed perusal of Met Office data^v for the Welsh data sites in the Met Office’s records. Fortunately there are only four of them, and they provide data for what seems to me to be a surprisingly short, and certainly disappointing, length of time. Of course, the shorter and less complete the data, the sillier are dramatic claims of “record” weather of any type. Be that as it may, let’s take a look.

Aberporth

The data from this site^vi, if anything shows a less wet trend lately, with the wettest month since the detailed records began in January 1941, being November 1954.

Individual months there with more than 200mm of rainfall are: September 1950; November 1954; November 1959; November 1960; January 1974; October 1981; October 1987; November 1997; November 2009; and December 2015. I don’t see a trend there towards much wetter or record rainfall recently. February 2020 saw 150.8mm. In fact the only two months to see more than 220mm of rainfall were November 1954 and November 1959.

Cardiff Bute Park

Here the data^vii begins only in September 1977. Since then, months with more than 200mm of rainfall are: December 1978; March 1981; September 1981; January 1984; November 1984; January 1988; November 1992; December 1993; January 1995; August 1997; October 1998; January 1999; August 1999; December 1999; October 2000; October 2002; November 2009; December 2012; October 2013; January 2014; November 2015; January 2016; October 2019; February 2020; December 2020; and May 2021.

Clearly Cardiff is wetter than Aberporth, and this time (albeit we don’t have 1950s records to compare with) the data seem to show an increasingly wet trend, with 5 months of 200mm+ rain in the 1980s; 7 months in the 1990s; 3 in the 2000s; 6 in the 2010s; and 3 already in the 2020s.

However, Cardiff being so much wetter, extreme rainfall here is more readily gauged by looking at months with more than 250mm of rainfall. These were August 1997; October 2000; and December 2020. That doesn’t like much of a trend towards increased heavy rainfall, especially as, of those three, the wettest was October 2000. There’s no denying that February 2020 was wet, but it falls 24.9mm behind October 2000.

Cwmystwyth 

Dataviii for this site in mid-Wales goes back to January 1959, but rainfall data commences only in January 1961.  

Since then, months with more than 200mm of rainfall are: August 1962; September 1962; December 1962; November 1963; December 1964 (334.8mm); January 1965; September 1965; December 1965 (417.3mm); December 1966 (419.8mm); September 1967; October 1967 (400.1mm); December 1967; January 1968; January 1969; August 1969; November 1969; December 1969; February 1970; April 1970; October 1970; November 1970 (304.2mm); November 1971; April 1972; November 1972; November 1973; December 1973; January 1974; July 1974; September 1974; October 1974; November 1974; December 1974 (305.9mm); January 1975; October 1976; February 1977; November 1977; December 1977; November 1978; March 1979; May 1979; August 1979; November 1979; December 1979 (315.8mm); June 1980; October 1980; November 1980; December 1980; March 1981 (350mm); September 1981; October 1981 (356.1mm); November 1982; December 1982; January 1983; September 1983; October 1983; December 1983; January 1984; September 1984; October 1984; November 1984; June 1985; August 1985; January 1986; October 1986; November 1986 (315.4mm); December 1986 (356.4mm); October 1987; January 1988; March 1988; July 1988; August 1988; September 1988; February 1989; March 1989; October 1989; January 1990; February 1990; October 1990; December 1990; November 1991; March 1992; August 1992; October 1992; November 1992; December 1992; January 1993; July 1993; January 1994; March 1994 (323.1mm); October 1994; December 1994 (350.1mm); January 1995 (324.2mm); February 1995; October 1996; February 1997; November 1997; January 1998; March 1998; June 1998; September 1998; October 1998 (354.4mm); January 1999 (302.4mm); February 1999; October 1999; December 1999 (347.4mm); February 2000; October 2000 (352.5mm); November 2000 (424.4mm); December 2000; October 2001; November 2001 (311.6mm); January 2002; February 2002 (401.3mm); October 2002; November 2002; December 2002; December 2003; January 2004; September 2004; October 2004 (333.3mm); December 2004; November 2005; December 2005; October 2006; November 2006; December 2006 (304.2mm); January 2007; July 2007; December 2007; January 2008 (348.9mm); March 2008; August 2008; October 2008 (317.6mm); November 2008; July 2009; November 2009 (425.4mm); July 2010.

Unfortunately the site closed in March 2011, so further comparison is impossible.   However, what (other than the fact that Cwmystwyth is very wet) can we discern?

Months per decade with more than 200mm of rainfall: 1960s (incomplete): 17.   1970s: 26.   1980s: 31.   1990s: 30.   2000s: 32.   At first blush, a dry 1960s, wetter 1970s, thereafter wetter still, but fairly stable for the next three decades.   But let's look a little deeper.   How many months per decade with more than 400mm of rain?

1960s (incomplete): 3
1970s: 0
1980s: 0
1990s: 0
2000s: 3.

On the face of it, no trend there towards excessive wetness, given that the 2000s (a complete decade) had the same number of very wet months as the 1960s (an incomplete decade).

How many months per decade with 300-400mm of rain?

1960s: (incomplete): 1
1970s: 3
1980s: 4
1990s: 6
2000s: 6

Added to the 400mm+ months, maybe that does show a trend to increasing wetness. And the wettest month was November 2009. It’s a pity we have don’t have data for the last ten years.

Valley

Data^ix for this site in Anglesey goes back to December 1930.

It is less wet than the other three weather station locations, so I have restricted my search for heavy rain there to months with more than 150mm of rain. They are as follows, by decade:

November 1931; December 1934 (240.5mm); September 1935; November 1935; October 1937; October 1938; November 1938; January 1939.

January 1940; November 1940; January 1942; November 1946; January 1948.

September 1950; November 1951; October 1954; November 1954; August 1956 (210.4mm); September 1958; November 1959; December 1959.

November 1960; October 1961; December 1964; December 1965; October 1967; November 1969.

November 1970; September 1974; February 1977; December 1979;

March 1981; October 1981; November 1982; December 1986; October 1987.

1990s: None.

October 2000 (209mm); November 2000; (220mm); October 2002; November 2002; October 2005; October 2008; November 2009 (205.6mm).

October 2013; January 2014; October 2014; December 2015 (254.2mm).

December 2020; October 2021 (provisional) (201.2mm).

By decades, then, we saw the following numbers of months with more than 150mm of rainfall:

1930s (incomplete data): 8

1940s: 5

1950s: 8

1960s: 6

1970s: 4

1980s: 5

1990s: 0

2000s: 7

2010s: 4

2020s (so far): 1 definite, 1 provisional (but likely to be confirmed).

I don’t see an increasing trend to wetness in those statistics, though I will concede a moderate increase in occasional particulaly wet months – months with more than 200mm of rainfall were December 1934; August 1956; October 2000; November 2000; November 2009; and December 2015. December 2015 was the wettest month, but the second wettest was December 1934. It’s worth noticing how dry were the 1990s and 2010s. Nothing supports the claim that there was record rainfall in February 2020 (which saw only 113.4mm of rain).

Ross-on-Wye

This site isn’t in Wales, but it is only just across the border, and in view of the paucity of rain data for Wales at the Met Office website, I thought it would be worth reviewing, in case it supported the BBC’s claims and undermined my argument.

Happily, the data^x for Ross-on Wye goes back to December 1930. It’s one of the driest of the data sites I have looked at, so in terms of looking for unusually wet months, in this case I have set the threshold at 125mm per month:

November 1931; October 1932; December 1934; November 1935; July 1936; January 1939.

November 1940 (158.2mm); January 1943 (161.3mm); December 1945; March 1947 (176.6mm); October 1949 (155.9mm).

February 1950; November 1951 (180.8mm); November 1954 (177.8mm); May 1955; February 1958; September 1958 (158.0mm); November 1959; December 1959 (186.0mm).

October 1960 (170.0mm); November 1960; November 1963; May 1967 (157.0mm); October 1967.

January 1970; November 1970; January 1974; September 1976 (162.4mm); October 1976; August 1977; December 1978; December 1979.

September 1981 (151.8mm); December 1981; November 1984; August 1986; October 1987; December 1989 (150.7mm).

January 1990; February 1990; January 1995; August 1997; January 1999.

April 2000 (172.0mm); October 2000; November 2000; December 2000 (177.0mm); October 2001 (162.3mm); February 2002; October 2002 (183.2mm); October 2004; October 2005; May 2007; June 2007; July 2007 (161.1mm); July 2009; November 2009 (168.1mm).

April 2012 (184.9mm); June 2012; November 2012; October 2013 (184.0mm); January 2014 (180.5mm); February 2014 (168.1mm); December 2015; March 2018; June 2019; October 2019.

February 2020 (162.6mm); October 2020; December 2020 (174.6mm); May 2021; October 2021.

By decade, the number of months with more than 125mm rainfall (of which, months with more than 150mm are in brackets following):

1930s (incomplete): 6 (0).

1940s: 5 (4).

1950s: 8 (4).

1960s: 4 (2).

1970s: 8 (1).

1980s: 6 (2).

1990s: 5 (0).

2000s: 13 (6).

2010s: 10 (3).

2020s (to date): 5 (2).

From this it can be seen that the 1950s were wet (December 1959 remains the wettest month in the entire series), there followed some dry decades, culminating in the 1990s, since when it has turned wet again. The wet start to the 21^st century cannot be denied, but the 2010s were actually less wet than the 2000s. Can we discern a definite trend, or is this just natural variability?

Conclusions

We have data from four Welsh weather stations to work with. The most complete one (Aberporth) doesn’t show an increasing trend towards wetness; Cardiff (not so complete, but up to date) might indicate a trend towards more rainfall, but not to increased excessive rainfall, and neither of these stations, or Valley (the three with up to date data) support the BBC’s claim (on the contrary, they actively contradict it) that “Storms Chiara, Dennis and Jorge led to record rainfall in February 2020.”

Furthermore, although data from Cwmystwyth, in mid-Wales does support claims that things are turning wetter, the lack of data since 2011 means that the vital information is missing (and given the dry 2010s at Valley, that missing data might be important in assessing rainfall trends). Even throwing Ross-on-Wye, from just over the border, into the mix doesn’t alter the central finding: the key claims in the BBC report (that flooding is the new reality in Wales, and that February 2020 saw record rainfall there) are disinformation.

Endnotes

i https://cliscep.com/2021/11/17/the-bbcs-latest-unreality-check/

iihttps://cliscep.com/2022/02/14/malinformation/

iii https://www.bbc.co.uk/news/uk-wales-60386125

iv https://www.bbc.co.uk/news/uk-wales-51604946

v https://www.metoffice.gov.uk/research/climate/maps-and-data/historic-station-data

vi https://www.metoffice.gov.uk/pub/data/weather/uk/climate/stationdata/aberporthdata.txt

vii https://www.metoffice.gov.uk/pub/data/weather/uk/climate/stationdata/cardiffdata.txt

viii https://www.metoffice.gov.uk/pub/data/weather/uk/climate/stationdata/cwmystwythdata.txt

ix https://www.metoffice.gov.uk/pub/data/weather/uk/climate/stationdata/valleydata.txt

x https://www.metoffice.gov.uk/pub/data/weather/uk/climate/stationdata/rossonwyedata.txt