April sunshine totals 1981-2010

Figure 1

The sunniest place on average in the UK in the period between 1981 and 2010 is Shanklin on the Isle of Wight with 201.4 hours. In fact most of the climate stations in the top 17 can be found on the English Channel coast somewhere. On the southwest peninsula the fall off in sunshine the further away from the coast you are looks to be around 10%. The Met Office provide these 1981-2010 average in their DataPoint web service and are not neither straightforward to download or to parse, because they’re all in XML format and come as individual files for almost 300 locations. The things I have to go through for a climate story.

Figure 2

I contacted the Met Office at Jersey yesterday and asked them what their record highest April sunshine total and got this tweet back.

Figure 3

I make their total for the same period 249.5 hours, yesterday they had another 2.5 hours taking them up to 252.0 hours. I’ve tweeted the Met Office at Jersey and asked them to check their total, but so far have had no response. As far as I can see I’ve done the maths correctly, and my old maths teacher Mr Brightmoor I’m sure would have been proud of me. The 1981-2010 average for Jersey is 196.5 hours in April, so that makes the latest anomaly just over 28% above the average.

Figure 4

Over 2,000 Met Office employees

I was really very surprised to find the other day that the Met Office had over two thousand employees. I found the information in their 2015 Employee Profile, and on the 31st of January 2015 it reported that they had 1,806 full-time and 239 part-time employees on their books, which adds up to 2,045 in total. I say very surprised, because I thought the total was closer to 1,500, but I may have been mixing that up with just the number of people who worked out of their Exeter HQ.

I won’t ask the obvious question, because I’m sure you can probably guess what that is, and because until just over five years ago I was one of ‘two thousand’, but I would have thought that with never-ending automation, and the rundown of our military bases in recent years, that numbers would (or should) have contracted and be closer to one thousand rather than two.

It was also interesting to see that the oldest person working for them was 71 years of age, and that there were 65 people over the age of 60 still working on. By law, I think that they’re required to publish their employee profile and diversity data which is a good thing, I wonder if Google, Microsoft, Amazon are obliged to do a similar thing.

If this wasn’t a polar low the next one could be…

Figure 1

The small low pressure in the Moray Firth at the moment (fig 1) doesn’t quite fit the bill as a classic polar low according to my old copy of the Meteorological Glossary. It describes a polar-air depression as:

A SECONDARY DEPRESSION of a non-frontal character which forms, more especially in winter, within an apparently homogeneous polar AIR MASS; near the British Isles the development is usually within a northerly or north-westerly airstream. The chief characteristics of this type of depression, which seldom becomes intense, are a movement in accordance with the direction of the general current in which the depression forms, and the development of a belt of precipitation near the depression centre and along a trough line which often forms on the side farther from the parent depression where also the pressure gradient (and surface winds) is increased.

Meteorological Glossary (6th edition 1991) Courtesy of the Met Office ©Crown Copyright

In this morning’s visible satellite image (fig 2) the trough, which the Met Office have as a wrap round occlusion in their midnight analysis, would usually occur on the western side of the low in this situation, or so says the glossary, but not with this feature looking at the imagery and the weather radar (fig 3).

Figure 2

Figure 3

The precipitation is of snow across the north of Scotland down to quite low levels this morning, and warnings have been issued by the Met Office (fig 3). I hadn’t notice that the Met Office had finally updated the dreadful mapping that they use in their warnings, a lot smarter, but about time.

Figure 4 – Courtesy of the Met Office

Although this low might not be classed as a classic polar low, a proper one might be developing off the coast of eastern Iceland, because the latest pressure falls at Torshavn (fig 5), indicate either a trough or maybe even a proper polar low might be squeezing itself into the tight northerly flow and head southward later today (fig 6), so you never know.

Figure 5 (the wind directions maybe spurious at times)

Figure 6 – Courtesy of OGIMET

A little white lie from the Met Office

Quite a lot of things annoy me about the Met Office as regulars readers of this blog will have no doubt picked up over the years. One of the worst traits that they have, is when talking about climate statistics for the UK, they use the following phrase:

“When records began in 1910…”

When you know full well that detailed records existed much earlier than that. What they ought to say, which is much close to the truth, is:

“We’ve only managed to digitize records back as far back as 1910, and even though we hold detailed climate records that go as far back as the early 1850’s, we can’t be bothered to do anything with because we’ve already spent the money on a big new shiny supercomputer.”

There is a classic example of that on their website today concerning the occurrence of frost in the UK during April.

Figure 1 – Courtesy of the Met Office

“Detailed frost recording in the UK began in 1961”. What a shocking admission for the national weather service of a country that was established in 1854. That must mean all of the sterling work done by meteorologists before 1961 was all in vain and a complete waste of time. What happened to all the temperature records between 1854 and 1960? At random, I picked out a copy of the DWR for January 1917 just to see if there were any extreme temperatures reported back then, and unsurprisingly there they were, for thirty-three stations across the British Isles (fig 2). Of course that’s just the tip of the iceberg, because like today, many more climatological returns from stations remain unpublished and go straight into the archives.

Figure 2 – Courtesy of the Met Office ©Crown Copyright

Absolutely no excuse

The Met Office were one of the first big users of computers and still are, here is a list of the computers that they’ve used down through the years (fig 3). I realise that looking forward with NWP model is vital, but so is looking back, and treasuring the climate data that previous generations have made since 1854. But why is it that climate records have always seemed to have been neglected, and climate data limited and inaccessible when there seems to have been no lack of one of the world’s fastest supercomputers at their disposal?

Figure 3 – Courtesy of Wikipedia

The Met Office have the resources, both in terms of staff and computing power to digitize the rainfall, temperature and sunshine records of the past and extend the gridded data series that they already have, back at least 50 years before 1910, but they have chosen to leave that wealth of old climate data untapped, and for the life of me, I just can’t understand why?

Extreme Easters since 1772 in Central England

Figure 1 – Data courtesy of NCEP/NOAA 20th Century Reanalysis

The Met Office beat me to a story about extreme Easters of the past, but undaunted, and without the masses of climate data they have at their disposal, I pressed on with a bit of research of my own.

Because Easter is not at a fixed time each year it’s difficult to compare one with another. Easter Sunday can fall as early as the 22nd of March or as late as the 25th of April. I’ve used the daily CET series from 1772 (now there’s a surprise), and calculated a five-day mean, from Maundy Thursday to Bank Holiday Monday to do my comparison with. Because of the time range that easter can fall, I have base it on mean temperature anomalies rather than the mean temperature. So from what I’ve found the coldest Easter period since 1772 occurred in 1892 (fig 3). The Easter Sunday that year fell on the 17th of April so it was by no means early.

Figure 2 – Data courtesy of the Met Office

The mean temperature for the five days between Maundy Thursday and the Bank Holiday Monday in 1892 was 2.1°C, which was -6.4°C below the long-term average for that period (fig 3). The weather chart for the Sunday (fig 1) shows just what a bleak and cold Easter that must have been in eastern parts.

Figure 3 – Data courtesy of the Met Office

I couldn’t resist including the Monthly Weather Report for April 1892 after using it to check out my story because I was taken with some of the phrases that were used by whoever wrote the report. I have highlighted some of them from the PDF that I accessed courtesy of the Met Office (fig 4). The remark about Vapour Tension exceeding 0.25 on the south coast of Ireland and England was a real charmer, I bet sixpence was a lot of money in 1892, and what happened to the Weekly Weather Report?

Figure 4 – Courtesy of the Met Office and ©Crown Copyright

Conversely, the warmest Easter using the same method, fell in 1926 in Central England at any rate.  Easter Sunday that year fell on April 4th, and the five-day mean was +6.5°C above today’s long-term average, and if you look at the synoptic situation (fig 5) you can understand why. I did look for any weather related news for Easter 1926, and mistakenly thought that this was the year of the Easter Rebellion in Ireland, but I was 10 years too late, that occurred in 1916.

Figure 5 – Good Friday 1926, data courtesy of NCEP/NOAA 20th Century Reanalysis

Look back at Sunday’s maximum temperatures

I thought that I would look back at yesterday’s (9th April 2017) maximum temperatures forecast by the BBC. This is not a moan about the temperature contrast across the south of the country, their most certainly was a good contrast, it’s more to do with the sites that the BBC choose as representative of their region and label in their graphics. The one that infuriates me the most is Plymouth in the southwest. There is a method in their madness though, because the Met Office bonus is dependent on how these extreme temperatures are scored in verification, choosing a coastal site (which is difficult not to do on an Island) can pay dividends, because the extremes, and therefore any potential misses are not as large. I believe that yesterday’s maximum temperature of 20.0°C at Exeter was more representative for the whole of Cornwall, Devon, Somerset and Dorset, than a forecast maximum of 14°C was for Plymouth, and even here the temperature reached 16.8°C. Rather oddly many of the temperatures on the chart don’t reflect the colour filled temperature contours that they are overlaid on, for example, a forecast maximum of just 16°C at Birmingham was always going to be wrong but the background colour is a mid-orange colour.

I think that I would have the full support of the South West Tourist board if the BBC put a little more thought into how they forecast regional temperatures.

Figure 1 – Courtesy of the BBC

I couldn’t help myself and resist scoring the maximum temperatures on the chart, if anything it underlines the fact that the Met Office model seems to have as many problems underestimating maximum temperatures as it does overestimating low cloud at the moment.

Figure 2

Why is forecasting low cloud so difficult?

I had ago at David Braine this week for his cloudier day forecast for Thursday. It wasn’t anything personal, I think he’s a pretty good forecaster turned weather presenter, he like a lot of other presenters was only towing the party and following the model, it was all to do with the output from the Met Office mesoscale NWP model. It seems to have a problem with forecasting low cloud amounts, especially in anticyclonic situations when it seems to overestimate the amount. They know about the problem, and according to their new blog Why is forecasting low cloud so difficult? it has to do with thin SC layers being missed by the coarseness in the vertical resolution of their model (100 M), combined with the difficulty in assessing SC amounts over the sea, especially when it’s masked by higher cirrus layers in satellite imagery.

I think there’s also another problem that they are missing, and that it’s either not possible, or difficult to tweak the graphics engine used to produce the graphics on TV. So the forecaster may know full well that the model is wrong or misleading from the evidence of the latest observations and satellite imagery, but they can’t quickly adjust the graphics à la Photoshop. I use Krita which is a free drawing package, and it comes with dozens of different pens and tools to draw and edit with, it surely wouldn’t be difficult to configure a pen that dissolves cloud layers?

This problem won’t necessarily go away when MeteoGroup take over at the BBC, but that’s of course dependent on whether the BBC stipulate that they use Met Office model data. Perhaps the new weather graphics engine that the Met Office now use internally and at the ITV, Visual Cortex , does make it possible to edit NWP forecast frames, if it doesn’t it should.

6 April 2017 – Low cloud and the BBC forecast

Figure 1 – Courtesy of the BBC

It was plausible that the SC that was sat over the Irish Sea late yesterday would migrate SE overnight in the Northwesterly flow to cover most of the southwest of England but not to the extent shown on the 09 BST forecast frame (fig 1), compare it with reality in the shape of the 1015 BST visible satellite image (fig 2), and you can see just how the Met Office model has overdone the amount of low cloud this morning. The Met Office NWP model does very well with fast-moving storms such as Doris, but it seems to have big problems in forecasting amounts of low cloud in anticyclonic situations such as this.

Figure 2 – Courtesy of the Met Office

One other criticism that I have of the weather forecast on Spotlight Southwest and that’s the humidity displayed in a caption at the top of the forecast graphics (see fig 1). It’s ridiculous that any single value can have any significance for anywhere in the region, and gives the wrong impression about humidity, relative humidity varies immensely. Why not just replace the humidity caption by occasionally displaying a colour contoured relative humidity chart? This would at least show the viewer how much humidity varies across the region (fig 3) and be a lot more educational and scientific in the process. In passing, the 64% forecast for 09 BST might have been just a little over optimistic!

Figure 3

Still on course for a change in type

We’re still on course for a change in type during by the weekend as the low pressure complex slips away south and high pressure builds across the north of the country, and an easterly flow becomes established. This change may not last too long according to the GFS, but it will make a change to the cloudy, mild southwesterlies that we’ve had for most of March. The weather next week always looks more settled over the north, especially the northwest of Scotland than it does in the south, with strong easterly winds across the south.

Figure 1

I noticed that John Hammond mentioned warmer weather by the weekend on the 1 PM BBC forecast, this must be somehow connected to a pulse of warmer/less cold air being caught up by the easterly flow from the continent on Saturday.

Figure 2

I always thought that high pressure was synonymous with fine weather – well not according to the Met Office and their forecast chart for Friday at any rate, which has four separate occlusions draped across the anticyclone (1033 hPa) that’s centred over the British Isles.

Figure 3