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Extreme Daily Rainfall At Bradford

March 28, 2014

By Paul Homewood

 

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http://www.metoffice.gov.uk/media/pdf/4/8/Drivers_and_impacts_of_seasonal_weather_in_the_UK.pdf

 

I looked yesterday at the Met Office’s claim that :

 

There are suggestions, however, that the character of daily UK precipitation has changed over the last 50 years. There is evidence that heavy rainfall events may have become more frequent over time: What in the 1960s and 1970s might have been a 1 in 125 day event is now more likely a 1 in 85 day event (see figure 4.1)

 

As I pointed out, their time series began in the 1960’s, the start of an unusually dry period. Doing the same exercise, using Oxford data starting in 1930, showed that there was no increasing trend of heavy rainfall events there, and that the rise shown on the Met Office graph was simply part of a cycle.

I also have daily rainfall data from the Met Office for Bradford, which goes back to 1911, giving us a longer perspective. It also gives a good geographical counterpoint to Oxford, as Bradford sits in the north of England.

So, using the same approach as the Met Office, I have identified daily rainfall of >22mm as being roughly 1 in 100 day events – over the 100 year period there are 381 of these.

The chart below shows the number of such days each year, with a 5-Year running average.

 

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As was the case with Oxford, there is no increasing trend, and the number of extreme rainfall days in recent years is not untypical, when compared against the rest of the record.

The year with most extreme rainfall days was 1928, which had nine. It is also worth noting that the wettest day on record was 15th August 1986, when 82.8mm fell.

 

I can only repeat. The Met Office have all this data available and should know all of this already.

Their persistence in publishing a misleading, half set of facts may be due to incompetence or because it suits their agenda. Either way, it reflects very poorly on them.

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7 Comments
  1. John F. Hultquist permalink
    March 28, 2014 2:28 pm

    It (almost) seems the head of the office asks the coders to make and run a routine that finds a string of numbers that supports an idea she/he wishes to make to the BBC and other news outlets. The readers/viewers are fed the story and have little reason to question the experts. Next week, repeat this process. Were I to be the underling tasked with such a request I would soon be suffering from “emotional distress” – a state covered by tort law in the USA.
    ~~~~~~~~~~
    There is a Bradford, Pennsylvania (north central part of that state) and just over a 1 hour drive from where I was raised. I had to look yours up.

  2. March 28, 2014 3:00 pm

    Another great piece of factual analysis, Paul.

    It would be interesting for you to prepare a selection of graphs of temperature, rainfall or whatever; add no identifying information; then send them to the MO and Sir Mark Walport’s office and challenge them to draw and publish their interpretations and conclusions.

  3. Anoneumouse permalink
    March 28, 2014 4:34 pm

    ‘extreme normal weather’

  4. March 28, 2014 5:24 pm

    Hi Paul, great work as usual, not sure how you find time for all this but it is much appreciated.

  5. March 29, 2014 2:27 pm

    Reblogged this on CraigM350.

  6. June 1, 2014 6:06 pm

    The MO and Newcastle University have predicted a “significant increase in summer flash floods by 2100.

    http://www.bbc.co.uk/news/science-environment-27624478

    The only problem is, this prediction appears to be bases on 1 model run and “the most high-end climate projections from the Intergovernmental Panel on Climate Change”

    Given that the temperatures are currently at the low-end of predictions, what makes them think this is a valid assumption?

  7. June 1, 2014 10:27 pm

    On a report on tonight’s News, Dr. Elizabeth Kendon said:

    “This model in incredibly realistic.”

    What she meant was “This model is incredibly complex and our super computer is incredibly powerful”

    The scientist are so impressed by the complexity of their models that they confuse that with accuracy.

    We won’t know how “realistic” it is for 90 years.

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