By Paul Homewood.
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The controversy over the Met Office’s “record rainfall” claim refuses to die down!
One reader challenged the Met Office over this, and received this reply. His questions are in bold:
1. Are you saying that the record in the link you refer to (Bruton) is from a non standard site?
Yes the daily data from the contributors to early British Rainfall are not currently included in the digital Met Office climate archives from which we quote the UK extremes. The extremes quoted by the Met Office are for consistency using the historical network of official observing stations, but wider Met Office archival material including the British Rainfall publication are available in the public domain.
2. Why do you compare a site halfway up a mountain (1100 feet) to those at sea level?
We monitor climate across the range of climatic conditions of the UK. Reported extreme values reflect the extremes of UK climate but do not make any direct comparison of one location to another.
3. Do you accept data from the EA, is this not ‘non-standard’?
The EA and Met Office have a long standing collaboration for monitoring UK rainfall. EA gauges meet appropriate standards and are used for climate monitoring.
4. How long has your organisation been referring to rainfall records from this station?
The Honister Pass rain gauge has been reporting since 1970
5. Why was this duration not mentioned in your press releases?
The duration of the individual rain gauge series does not relate to the nature of the specific record being quoted.
We hope that you find these answers useful.
Taking each question in turn:
1) I agree there is a certain logic in just using a list of long running, high quality stations, when making claims about records, and for that matter trends. There is always some doubt about the accuracy of many old records.
However, there is a huge problem with this approach, because the Met Office now have many more such sites available nowadays, thus making “extreme rainfall and temperature” events much more likely to be spotted.
Indeed, just using “long running sites” is the opposite of what the Met office are doing, as they are more than happy to use sites with just a few years data.
Below is a map of station networks used by the Met Office for calculating climate trends and providing daily data, and the growth in the number of stations is self evident.
The reason for this growth is simple. All of this data now needs to be in digital form, which data in recent decades already is. It is relatively easy to digitalise a few years of earlier data, as it is all kept in a similar format. It is, however, much more difficult to go back to the 19thC and have to digitalise from scratch, especially when records are kept in different places.
In addition, of course, the absence of automatic rain gauges in the past often meant that there was no reliable daily data in upland areas until recently.
This issue also raises serious questions about long term trends, as many of the newer stations are at high altitude, where rainfall is inevitably heavier. Although the Met Office claim they “homogenise” for this, it is highly possible that recent national rainfall figures have been skewed upwards as a result.
2) The Met Office claims:
Reported extreme values reflect the extremes of UK climate but do not make any direct comparison of one location to another.
This, of course, is an outright lie. By claiming a “new record” at a mountain site in place of a lowland site, they are doing just that. (I should point out that they still have not published what and where the previous record was).
3) The Met Office claim that Honister Pass is a “standard site”, because it uses an approved gauge. This, however, totally sidesteps the point, that half way up a mountain is NOT a standard site.
Even more disingenuously, however, their inclusion of Honister breaks their own rules, as laid out in 1). That is, they only count records using their own historical network of official observing stations.
Honister is not one of these, as confirmed by the Met Office themselves in their own list of Climate and Synoptic Stations here.
4) and 5) Again this is an utterly dishonest reply.
The duration of the individual rain gauge series does not relate to the nature of the specific record being quoted.
Of course it does. As they are comparing apples and oranges, all their supposed new record proves is that the Honister rainfall is the highest since, at best, 1970. Even then, we know that measurements have been spasmodic since the, so we simply don’t know whether higher daily rainfall totals have occurred in the meantime.
To sum up, the Met Office have ignored incontrovertible evidence that more rain fell in Somerset in 1917, on the basis that Bruton was not formally included in their official network of observing stations.
Yet they are keen to declare a new record at Honister, which is not only not a totally unsuitable site with just a few years of actual data, but also just happens to be not part of their official network of observing stations.
Their hypocrisy and mendacity is astonishing.
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July 9, 2020 at 02:48PM
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