State of the UK Climate 2016

The Met Office have just released the third edition of their State of the UK Climate for 2016. I always find that this a strange time to publish such a document, why not by the end of January? But once you have taken a look at the 59 page document, you’ll see that it must take a lot of work to put it all together, and I am just being my old curmudgeonly self.

There’s an interesting correction at the foot of the article about CET, which as most of you know is something I like to talk about at length. I find it amazing how people scour the climate datasets to pick out a new extreme, be it high or low, this one’s no exception – decades that span 10 years but don’t start on a year that ends in a zero aren’t what I would call a decade. It’s time to see what the Collins dictionary definition of a decade is:

A decade is a period of ten years, especially one that begins with a year ending in 0, for example 1980 to 1989.

So they are strictly correct, but personally I still like to think of a decade as a period that starts with a year that is divisible by 10 without a remainder, as the Collins dictionary definition suggests it is. Anyway back to the correction, what they were initially said was that the period 2007-2016 was the warmest ‘decade’ in the whole series back to 1659. Obviously they noticed that something was wrong, and said it was incorrect. I wonder why they didn’t just delete the reference in the HTML? I was certainly late on this one and never saw the original.

Just out of interest, here is a centred 10 year moving average of monthly CET values since 1900 (fig 2), and as far as I can see, the warmest decade was the one from 1997 to the end of 2006, when the mean 10 year anomaly for the first time just exceeded +1.0°C, since then, Central England has cooled, until about 2012, when annual anomalies increased sharply again. I think the reason they corrected the original article could have been for a typo, because 2007-2016 and 1997-2006 are just ten years apart. They can always ask me to provide them with graphs, I have a graph of CET values to suit just about any occasion, and the bonus is that I work cheap.

Figure 2

Here for completeness is the full 10 year series of moving averages since 1659 (fig 3).

Figure 3

 

You don’t often see that on a weather chart

Figure 1 – Courtesy of the Met Office

It might look like they’ve not quite finished drawing the midnight analysis chart, but the Met Office reckon that there was some kind of upper warm sector off the southwest of England (fig 1). The analysis chart is looking more like a nephanalysis than ever, the chief was obviously in quite an artistic mood on the night shift last night, because he also picked out a couple of other squiggly troughs that he’s added to the chart. There’s certainly a lot of upper cloud in that area on the infra-red satellite image for midnight (fig 2), and very likely it’s tied in with the jet stream that’s blowing at over 100 knots from the W’SW at the moment. I can’t see much sign of the feature on the visible imagery today, and certainly little in the way of weather, perhaps it was responsible for the non-appearance of the rather frequent showers that they had forecast for today across the southwest.

Figure 2

Here’s a key to the symbols that the Met Office use in their weather charts below (fig 3).

Figure 3 – Courtesy of the Met Office

Heavy rainfall event over Germany

Figure 1

When I initially generated this rainfall chart for Germany since the 1st of July, I thought that the total for the Brocken looked spurious, 418.4 mm looked way too high for July, even for the top of a 1,152 metre high mountain, so I had a look at the underlying SYNOP reports to verify it and found that it was accurate (fig 2). There has been a lot of rainfall in the last couple of days across middle and northern Germany, and I believe it’s causing some issues their with flooding.

Figure 2

I did find a graph of rainfall for the Brocken so far this year on the DWD website that confirmed the totals of the last few days (fig 3).

Figure 3 – Courtesy of the DWD

According to Wikipedia the average rainfall for the Brocken is 150.6 mm for the month of July, so we are looking at almost three times the 1981-2000 long-term average.

High dewpoints

The dewpoint here in mid-Devon is 18°C at the moment, but hopefully behind the cold front thats’ now clearing Cornwall they should fall to something more comfortable later this afternoon. I notice that there are now some single figure dewpoints now across Ireland.

Italian rainfall in last month

Figure 1

In view of the drought conditions in Italy, I thought that I would look back at the rainfall during the last month. It’s not 100% accurate because of missing observations from some stations. Rather surprisingly I did find some accumulations, not a lot, and probably not enough to halt the drought, but there has been some. Let’s hope there’ll be more in the coming months.

Spot the cold front

It’s almost impossible to spot the cold on the 08 UTC weather radar this morning across Ireland (fig 1).

Figure 1

I had a stab at where it was on the plotted SYNOP observations for the same time (fig 2).

Figure 2

I then had a go using the latest visible satellite image, which ends up a little more advanced than I had it using the surface observations (fig 3). The cold front is certainly very weak, and will probably be no more than a few spots of rain when it passes through later this morning.

Figure 3

 

The Italian drought

I thought I would just look at the SYNOPs for Rome’s Fiumicino airport since the start of the year and see how severe the drought that is that’s been affecting that part of Italy, and by the look of things it’s very severe indeed. The total rain I have found from the available SYNOPs is 131.4 mm (fig 1), which is not a lot in almost seven months, and according to the observations that I have the last 24 hour rainfall they reported was 4.6 mm on the 29th of June.

Figure 1 – Data courtesy of OGIMET

According to the Wikipedia article on the climate of Rome, the average rainfall from January to the end of July at the airport is 341.6 mm, so in 2017, there has only been a little over 38% of the average rainfall (1971-2000 long-term average). So it’s no wonder that the Guardian reports that all the fountains in the Vatican City were turned off on Monday of this week. And the reason for the drought? The bulk of annual rainfall in that part of Italy falls outwith the Summer months, but during last winter and spring the mean pressure across Italy and the Alps was much higher than average, this limited the number of depressions and rainfall events to affect that part of Italy. If I remember the Adriatic was quite stormy at times during the Winter, but the rain probably fell on the east coast and the Apennines and didn’t make it across to the west, well that’s my best guess anyway.

Figure 2

 

 

The Guardian – Why cutting soot emissions is ‘fastest solution’ to slowing Arctic ice melt

Courtesy of the Guardian

The BBC article about algae reducing the albedo of snow, reminded me about an article about a similar thing happening that was caused by soot particles, particularly from coal power stations and flare stacks at gas terminals. The Guardian article ran an article about it in December 2016 which said:-

World leaders should redouble efforts to cut soot emissions because it is the cheapest and fastest way to combat climate change, climate scientists and advocates have told the Guardian.

Deposits of soot – unburned carbon particles – have stained parts of the Arctic black, changing the ice from a reflector of sunlight to an absorber of heat, and accelerating the melting of ice and snow, which itself is starting to alter global weather patterns.

BBC – Sea level fears as Greenland darkens

Image courtesy of the BBC

A BBC news article says that Scientists are “very worried” that the melting of the Greenland ice sheet could accelerate and raise sea levels more than expected. They say warmer conditions are encouraging algae to grow and darken the surface. Dark ice absorbs more solar radiation than clean white ice so warms up and melts more rapidly. Read more here.

Thunderstorm Exeter at 3 pm today

Figure 1 – Courtesy of the BBC

It will be interesting to see if there is a thunderstorm at 3 pm today in Exeter. The cumulus humilis is now sprouting up into cumulus mediocris, which is hardly surprising as the temperature is now 24°C here in mid-Devon, although Exeter airport have still not caught up with areas to the north that were unaffected by the fog and stratus earlier this morning.

Figure 2

The cumulus is visible on the visible satellite image for 1015 UTC (fig 3), as is the cloud that’s producing the showers in western Cornwall. There’s a nice hole is the SC sheet over the central highlands of Scotland, Aonach Mor reported a dewpoint of -13.4°C at 08 UTC in the clear air above the inversion. Plenty of cloud persisting in eastern areas, it should be better tomorrow and they might get some early sunshine before the rain arrives.

Figure 3