The “Shonk Effect”

It’s strange how the finest of sunny, spring weather can give way to cold, rainy weather practically overnight.

According to the automatic weather station on the field site, the temperature reached 20 °C for the first time this year during week 2. A mere four days later, the maximum temperature failed to reach 10 °C. Furthermore, the rainfall in week 3 was about three times that of the first two weeks combined.

Analysis of the weather charts reveals a marked switch in regime into the start of week 3. The end of April was dominated by high pressure to the south-east of the UK and warm southerlies. This anticyclone kept low pressure systems at bay, bringing us a period of fine, spring-like weather. By week 3, however, high pressure had built in the Atlantic, dragging colder air and low-pressure systems across the UK from the north. Quantifying this, the first two weeks of term brought 5 mm of rain — that’s 2.5 mm per week. The third week brought about 14 mm of rain.

In that third week, I had two WCD tasks: to write this blog, and to make a one-week-only return as the Slideshow. In weeks 1 and 2, all I had to do was go along and watch.

WCD aficionados may remember a presentation I gave in week 10 of the Autumn term, at the end of a five-week stint as co-presenter with Keith. In it, I compared the weather from our five weeks with the weather from the preceding five weeks. It was shown that 164.2 mm fell in the Shine-Shonk weeks (that’s 33 mm per week), while only 59.1 mm fell in the Rob-Ross weeks (12 mm per week).

I therefore propose a new meteorological concept called the “Shonk Effect”. It states that, if I have anything to do with the running of WCD in a given week, much more rain will fall than in the previous weeks.

In other words, the current rainy spell appears to be my fault.


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  • :-D says:

    Surely that would mean that during the 1 or 2 years you were being Slideshow Shonk, we would have had rubbish weather the whole time…?!

  • […] Another week of WCD and another fascinating selection of pretty pictures – of phytoplankton blooms in particular. But the image that inspired me most was the soil moisture anomaly of Europe, shown by Pete Inness when talking of the Polish floods (link). But my eye was drawn rather closer to home, seeing a 2-3 (unknown normalised units) dry anomaly across Southern England. This struck me as no surprise, I’ve needed to water the garden practically every day for weeks, but as was pointed out to me, this could well bring back a British media summer staple phrase, missing since 2006, “hosepipe ban“. Soil moisture of course is going to be largely based on the recent rain… Only 15.4mm at the atmospheric observatory in May up to the 27th (largely attributable to the Shonk Effect). […]


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