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Global Warming Causes New Type of Rain

'Monsoon style' floods to hit Britain - Telegraph

Lord Smith, Chairman of the Environment Agency, said Britain is experiencing a "new kind of rain" in the summer that is putting cities at increasing risk, especially London.


More details of this type of rain are available here or if you want to play with a set of numbers go here


Well, because it is interesting, I decided to take a look at the 'raw' data (in Englishman's linked file ewrain.txt). In fact, of course, it is not very raw but is (I believe) a combination of measurements from various spot locations, combined in weighted form to represent average rainfall over the whole country; that is a very reasonable thing to do. Anyway, I was somewhat concerned about the Met Office plot Englishman references, with its 4-month winters (including March) and 2-month high summers (rather than the 3-month periods in the data file), zero re-basing and scale normalisation implicit in the relative figures WRT 1961..90, and some extensive smoothing over time (not notified, let alone described).

Accordingly, I started by producing some plots of absolute precipitation for the 'standard' winter and summer periods: Dec-Feb and Jun-Aug, as given in the data file.

Very interesting, it seems the winter and summer precipitation for each year, year by year from 2004 to 2008, are very close to each other - so close the plots overlapped so one was not visible. In fact, as a percentage of their year-by-year average, the difference between summer and winter is (for 2004 to 2008): 2.58%, 2.54%, 0.76%, 0.26% and 0.34%. For the preceding 90 years, the variations between winter and summer precipitation are generally bigger and vary quite a lot.

I have checked that the calculated winter/summer figures for these 5 years are correctly calculated from the monthly figures (starting in the December of the previous year for winter), and they are. [Note: if anyone is interested in checking my work, I can email: screen captures of the plots, my slight modifications to the datafile format to make it suitable for GNUPLOT, and my plotting scripts.]

My two highest-ranked explanations are, in reverse order: (i) God and the angels are pissing themselves laughing to see how long it takes for us to notice, or (ii) there is some non-trivial problem with the combination of measurements from various spot locations to give the countrywide average, month by month - in which months (or at least quarters) are no longer independent.

Best regards

Basically, Nigel, you just confirmed what I suspected when I gave the data a cursory glance -- there's nothing much to worry about.

But "same ol', same ol'" doesn't sell newspapers, or give politicians an excuse to pass more laws.

*shakes head in wonderment* Global warming. Is there anything it can't do?

I saw that. A new type of rain that is much wetter. Due to MMGW. Brilliant.

@ Mac, global warming can even cause global cooling.


But it can't open cellophane packets AFAIAA

Global warming never ceases to impress me - it's been away on holiday for a decade and still works all these incredible wonders. Shrinking sheep here, causing dermatitis and anxiety there, cat flea epidemics, antisocial behaviour in polar bears and hippos, and all the rest of its bizarre tricks. And now a new kind of rain, never seen before - better not tell the rail companies, is what I say. "New kind of rain" will soon join "leaves on the line" or the "wrong kind of snow" as yet another reason for delays.

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