Still not convinced

Figure 1 – Courtesy of Met Office

I’m still not convinced by the midnight surface analysis from the Met Office. They have clung to this same ‘configuration’ of fronts (east to west) in all their forecast charts this week:

  1. Warm
  2. Upper cold (in the warm sector)
  3. Cold (returning warm)
  4. Cold (short)
  5. Trough (concave to west of Ireland)
  6. Occlusion
  7. Occlusion (bent back)

By sticking to this analysis they are certainly being consistent, but consistently wrong, because I can see little evidence of the frontal features 2, 4 or 5 in the weather radar at midnight. If they only could publish a synoptic review that explained the various features they have in their analysis and forecast charts and the thinking behind it, we then might be in a better position to understand the rationale behind it, but as far as I am concerned their approach is just far too complicated.

Figure 2 – Courtesy of Met Office


The KISS principle

Figure 1 – Courtesy of the Met Office

According to Wikipedia the acronym KISS means “Keep it simple, stupid” and was a design principle noted by the U.S. Navy in 1960.

The KISS principle states that most systems work best if they are kept simple rather than made complicated; therefore simplicity should be a key goal in design and unnecessary complexity should be avoided. The phrase has been associated with aircraft engineer Kelly Johnson (1910–1990). The term “KISS principle” was in popular use by 1970. Variations on the phrase include “Keep it Simple, Silly”, “keep it short and simple”, “keep it simple and straightforward” and “keep it small and simple”.

I’m usually reminded of the KISS principle when I see a forecast or analysis chart from the Met Office similar to the one above (fig 1), for some reason. You could argue, that a set of forecast charts is a system in its own right, and if it is, then why over complicate it? Met Office charts in the past weren’t always as complicated as they seem to be today, but try as I may, I can’t find any images of fax charts from the past on the internet to illustrate that fact.

The weather’s not bad this summer – honest!

I get the distinct impression from the recent news from the Met Office that they are trying to convince us that summer 2017 is not a complete wash out, well not yet anyway. Perhaps they have been urged to say that by a phone call from the Director of VisitEngland, Andrew Stokes (fig 1). As far as I can see, there was some lovely weather about in May and June of this year, but things went downhill in the first week of July, and at the moment don’t look like they want to improve, blame it on being the wrong side of the jet.

VisitEngland and the tourist boards around the UK, must know that the weather forecast has a tremendous part to play in motivating holidaymakers to get out and visit the various attractions around the country, so it’s no wonder that tourism looks to the Met Office to ‘gee’ things up in the weather forecast, especially now that the school holidays are here. I personally would rather hear it as it, than be coaxed into believing by weather presenters, headlines and news articles, that the summer up till now (and for the foreseeable future) is anything other than average.

Cool out last night

Figure 1

Quite a cool night in places across the country last night under clearing skies and cool air for August (fig 2). Marked contrast between the coastal stations and the more rural inland stations as you would expect with SST around the coast of 16 or 17°C. Exeter with a min of 5.1°C and Portland 14.1°C is just one example (fig 1).

Figure 2

A cool night was well anticipated by the BBC, but it was a little colder than they thought in the south of Scotland, the west Midlands and Devon. They never can quite anticipate just how cold it can get at Exeter airport, with a grass minimum of just 2°C (fig 3), and the Met Office supercomputer just a couple of miles up the road.

Figure 3 – Courtesy of the BBC on the 5 August at 1pm

The crafty Met Office

Of course the Met Office and the BBC are very crafty, and since the demise of the magnetic weather charts, they now always quote a spot value for a particular time as the minimum temperature, rather than the true ‘minimum’ temperature for the whole night, which in my opinion is much more useful, and less misleading. It’s my belief that they don’t display a minimum or maximum temperature chart to hinder any verification of their forecasts, and prevent smart Alec’s like me from saying just how far their forecasts were out by.

July’s CET values are delayed till someone at the Met Office can be bothered

Figure 1

I have a number of obsessions as you’ve probably noticed, most of them can be summed up as weather, climate and blogging. I first started my obsession with climate stats back in 1983 when I took a redundancy package from British Steel, and rejoined the Met Office. That package gave me enough money, the first in a few lean years after the steel strike, to buy a BBC micro computer, and one of the very first applications that I wrote using it was a BASIC program to visualise monthly CET data. The first job was to type in over 300 years of monthly mean temperatures, which took a while. Since then I have written a Windows application that does very much the same thing, but with a few extra bells and whistles. One of the first things I do after starting my PC each day is to download the latest CET from the Met Office, but recently the daily estimated data that I religiously download hasn’t been updated, usually this is for just a day or so, but occasionally it can go on for a week or more. No big deal for most, but it bugs me so I fire of an email and get the usual reply:

Figure 2

Of course, if the Met Office did free up and make their NCM climate data public, then I could calculate the CET values myself, I could add the three numbers up and then divide by three, for the maximum and minimum temperatures.

I can’t afford to pay the Met Office to access the climate daily data for Rothamsted, Malvern (I had always thought it was from nearby Pershore College) and Stonyhurst, which are the three sites that are used to calculate the composite temperature that we know as CET. Knowing my luck, even if I did pay for the service, it would prove to be just as flaky as the present CET system is and fail to deliver that data as well.

I don’t know why I’m that worried so much about July 2017, because I already know that it wasn’t in any way exceptional, and to most people this rant will seem even more petty. But to me, their attitude with CET exemplifies how casually they treat the climate data they collect on our behalf. Sure they share some of the monthly data to comply with the decree of a few years ago, but the holy grail to anyone interested in climate, is daily data, for all UK sites, both the latest and the archived, and that they jealously guard.

I am afraid it looks like that I’ll be forever beholden to the Met Office for access to the latest CET data.

It’s now four days since the latest estimated CET series was updated, I’m betting that normal service won’t return till at least Monday of next week, we’ll see. Of course very few if anyone at the Met Office will ever read this article, but as far as I’m concerned, one of the main reasons that you write a blog is to get things of your chest, and that I have now done.

I did get some good news from them this morning concerning this problem which I informed the Met Office of in June. It wasn’t wrong as I first though, just a bit misleading, because you don’t always expect Sunderland to turn up in the Lake District even if there is a small hamlet with that name there. Anyway that shouldnt happen again, I’ve been reliably informed.

Figure 3

Met Office more reactive than proactive in the issuing of yellow warnings

Figure 1

I’ve been blogging ever since I retired and that’s now well over five years. I spend a good deal of my time watching how the Met Office performs through its forecasts and the various warnings that it issues, and recently, well in the last few weeks actually, I’ve been asking myself what is the exact purpose of the yellow warnings they issue.

What the colours mean

  • Yellow – Severe weather is possible over the next few days and could affect you. Yellow means that you should plan ahead thinking about possible travel delays, or the disruption of your day-to-day activities. The Met Office is monitoring the developing weather situation and Yellow means keep an eye on the latest forecast and be aware that the weather may change or worsen, leading to disruption of your plans in the next few days.
  • Amber – There is an increased likelihood of bad weather affecting you, which could potentially disrupt your plans and possibly cause travel delays, road and rail closures, interruption to power and the potential risk to life and property. Amber means you need to be prepared to change your plans and protect you, your family and community from the impacts of the severe weather based on the forecast from the Met Office
  • Red – Extreme weather is expected. Red means you should take action now to keep yourself and others safe from the impact of the weather. Widespread damage, travel and power disruption and risk to life is likely. You must avoid dangerous areas and follow the advice of the emergency services and local authorities.

More reactive than proactive

After the recent flash flooding in Coverack (18th July) and that at Okehampton yesterday (30th July), I now realise that many yellow warnings simply aren’t working, and that the Met Office have become more reactive than proactive in their issuing of them. I am convinced that yesterday’s late afternoon yellow ‘warning’ for 1750-2000 BST was prompted as much by Twitter, as it was by mesoscale NWP guidance or observational data from weather radar, river level gauges, automatic rain gauges or AWS.

I’m sure that they had reviewed the situation in the morning, and had duly issued a yellow warning for heavy rain for the north of Scotland, the reason that they gave for that warning of 20-40 mm was that the showers would be slow-moving.

What happened literally on their own door step at Okehampton seems to have caught them totally unawares, perhaps they thought the showers in Devon were moving quickly, and hadn’t anticipated that ‘peninsula convergence’ might just keep them coming along the spine of Devon for much of the day. In the end Okehampton received 84.2 mm in the 09-09 UTC period. I can’t believe that these accumulations were not picked up by any of the earlier mesoscale NWP model runs, and a warning not issued at the same time as the one for the north of Scotland was, I would love to see what the models were indicating.

The thinking must be at the Met Office, that a yellow warning must be in place to ensure that they are covered from any fallout in any severe weather, so no matter how late in the day it is, a yellow warning has to be issued. I recall a similar thing happened with the strong winds on the 6th of June, a warning for strong winds could have been issued with the one for heavy rain the day before, but for some reason known only to themselves wasn’t, two men were killed by falling trees on that day. It wasn’t a warning, it came into force as soon as it was issued, and that’s not much help to anybody, similarly yesterday, everyone in Okehampton knew it had been raining heavily all day, and by the time the warning had been issued the worst was over.

Figure 2 – Flooding yesterday at Okehampton courtesy of Twitter and Gillian Cross

I noticed that in the Coverack flash flooding on the 17th of this month, although there was a yellow alert in force, a red alert was never issued. It may be that localised nature of flash flooding does not meet the criteria of ‘widespread’ for the issuing of a red warning, and that’s why one was never issued. If that’s true, that would mean that if the NSWWS had been in place in the past for the flash flooding at Boscastle in 2004 and Lynmouth in 1952, both events would have only warranted a yellow warning.

In yesterday ‘peninsula convergence’ heavy rainfall event at Okehampton, the Met Office did have time to give an explanation to its Twitter followers of what ‘peninsula convergence’ was, but they only managed to issue a belated yellow alert from 1750 BST, when heavy rain had been falling for much of the afternoon (fig 1 & fig 3), and don’t forget that yellow means “Severe weather is possible over the next few days and could affect you“.

Here is my estimated total from low resolution weather radar images of what fell before the warning was issued from 0900 – 1650 UTC. As you can see from the inset hyetograph, there had already been, in the worst affected areas, around 61.7 mm of rain in less than eight hours (fig 3).

Figure 3

And here is my estimated total of what fell during the duration of the warning (1655-1900 UTC), and as you can see in that time a maximum of 25 mm fell in just over two hours in the same area (fig 4).

Figure 4

Today’s warning

Figure 1 – Courtesy of the Met Office

A bit of an odd warning today from the Met Office for the north of Scotland (fig 1), it was issued this morning for 20 mm to as much as 40 mm of heavy rain from slow-moving showers, between 13 and 21 BST this afternoon (fig 1). Although there were a couple of areas of 16-24 mm accumulations from my weather radar estimates, it didn’t quite make it as high as 40 mm over northern Scotland, although it clearly did nearer to home down here in Devon, and that was entirely overlooked (fig 2).

Figure 2

A string of showers has been continually forming and streaming E’NE along the spine of Devon for much of the day, they may have been moving more quickly than the showers over northern Scotland, but they never stopped coming for the central swathe of the county. Here’s a closer look at the estimated totals from 13 BST today (fig 3), and as you can see, there is a stripe of 16-24 mm accumulations aligned WSW-ENE across Devon, and inside that an inner area of 32-50 mm, with a few red pixels indicating greater than 50 mm over northwest Dartmoor by the looks of it. Showers of this nature are not uncommon in the southwest, and although very localised, the totals do indicate intense rainfall.

Figure 3

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

And finally the infographic that the graphics team have produced to advertise the publication of the 2016 report is a bad idea to my mind. I love a well designed infographics – you only have to look at my blog to see that – and I do realise climate statistics are not the most exciting things to try to visualise, but a clear well constructed table or graph is really all you should need. Most of us have moved on from kindergarten I would have hoped, but they may have been instructed to produce a simple infographic for politicians the like of Michael Gove to understand what’s going on.

Figure 4 – Courtesy of the Met Office

This mornings rain from Zlatan

Figure 1

Quite a wet and windy morning in the southwest as low Zlatan moved across Ireland. Rainfall estimates from the radar from for 0600 to 1200 UTC (fig 2), indicate that generally totals were in the 16-32 mm range across Cornwall, with a large area of 32-40 mm further east in the county (lime coloured pixels), and 40-50 mm across Bodmin (yellow pixels). The chief forecast 10-20 mm in a short time in yesterdays yellow warning for heavy rain, but very cleverly he didn’t put any figure on the totals, which they’ve recently stopped doing – or is that another one of my conspiracy theories that I’ve invented in my dotage – so they can never be accused of either grossly underestimating or grossly overestimating rainfall totals in any event.

Figure 2

I reckon looking at the actual six-hour rainfall totals from the SYNOPs that I’m not far out (fig 3).

Figure 3

Cornwall’s had its turn, now it’s Devon’s.

When you just can’t get that yellow warning area quite right…

For as hard as the Met Office might try, they just can’t seem to get the area for today’s yellow warning of heavy rain and thunderstorms quite right. Here’s how the shape of the yellow warning area looked yesterday (fig 1).

Figure 1

And here’s how the shape looked after a belated adjustment at 0115 BST this morning, after overnight thunderstorms ran NE from the English Channel, and were a little bit more persistent than the model reckoned they’d be (fig 2).

Figure 2 – Courtesy of the Met Office

And here’s how the shape has looked since 1100 BST this morning (fig 3).

Figure 3 – Courtesy of the Met Office

But this is how it looks in reality right now (fig 4).

Figure 4

The moral of this story is whatever you do – never leave Snowdonia out of the heavy rain warning area.

Figure 5 – Courtesy of Blitzortung

As far as I can see, the best solution to the problem of continually having to update the area affected in thundery weather, would be to just slap a complete yellow alert across the entire country, for heavy rain, frequent lightning, hail and flash flooding, and be done with it (fig 6).

Figure 6