Storm catalogue 1871-2017

Figure 1 – Courtesy of the Spectator

Now that I’ve parsed and run an objective LWT analysis on the six hourly 20th century reanalysis data from NOAA, I can finally start putting some graphs together on what I’ve found. The gale index [GI] is a good place to start, and gives you a quick overview of how stormy it’s been over the British Isles in the last 145 years. Of course the calculation for the GI is for a fixed location 55° north and 5° west, so it has to be used with caution. The way round this would be to adjust the position of the grid, and generate the GI for other grid points, but for the moment GI values from a single point will have to suffice.

Figure 2

Without a doubt, the 1990’s was the windiest in the last 145 years, and it could be that 1990 was the windiest year looking at the graph of the total days when the GI>=30, approximately gale force 8 (fig 2). The winter of 1989-1990 was very stormy and of course that was the year of the Burns day storm. The best fit curve seems to be suggesting the number of gale force days per year has fallen since a little since then, it’s obviously only a rough guide, and the figures for the incomplete year of 2017 will be playing some part in that decline.

Figure 3

If you just examine all the six hourly charts in which the GI>=50 you get a slightly different picture (fig 3). The number of storms seems to have started to increase again since the peak in the 1990’s, and it looks like the stormiest year using the GI>=50 as a threshold was 2014. This finding corresponds well with what the Met Office said about the storminess of the winter at the time in a report entitled The Recent Storms and Floods in the UK so I must be on the right track (fig 3).

Figure 4 – Record of the number of stations reporting wind gusts in excess of 60 kts during December (Courtesy of the Met Office)

What the experts are saying about increased storminess

I’ve scoured the internet to find what climate scientists are saying about any increased storminess in recent years, with little success. I did find a PDF from Rob Allen of the Met Office about storminess from 2006 – Impacts of climate change on storminess – in which he said:-

Efforts are underway in the Hadley Centre at the Met Office to extend the 3-hourly pressure change analysis back to 1920 over the UK, while the potential exists to investigate whether very long-term pressure data series with coarser 12-hourly resolution at about 6 locations in the UK back into the 18th-19th century can provide a truly centennial scale picture of severe storm nature and changes.

I can’t say that I’ve seen any fruits from the efforts that the Hadley Centre were planning to make, but then again the wheels do tend to grind exceedingly slowly at the Hadley Centre, they are still under the illusion that climate data about frost only started in 1961, and temperature and rainfall in 1910. Perhaps I should point them at the masses of reanalysis data that I’ve downloaded from NOAA. It might only be on a 2° x 2° MSLP grid but at least the Americans encourage people to access the climate data that they produce.

If you have access to the Weather Magazine, there is an article about the subject – Historic storms of the northeast Atlantic since circa 1700: a brief review of recent research (Volume 69, Issue 5, May 2014, Pages: 121–125), in fact it mentions just how valuable the reanalysis approach might be in investigating changes in storminess.

Global warming and increased storminess

According to the Spectator in February 2014, Met Office scientists were privately furious with Professor (now Dame) Julia Slingo when she said that there was a link between global warming and recent storminess and the jet stream getting stuck. Professor Mat Collins of Exeter University was quoted in the Daily Mail as saying that:-

‘There is no evidence that global warming can cause the jet stream to get stuck in the way it has this winter. If this is due to climate change, it is outside our knowledge.’

The magazine claimed that Dame Julia had been hung out to dry by the Met Office because of these claims, one can only wonder about if there was a grain of truth in it, because by November 2016 she had been replaced by Stephen Belcher as Chief Scientist. Did she jump or was she pushed, or maybe she just thought sod it I’ve just had another £30,000 bonus, I’m 65 and I’m off.

There was a response to clarify what Mat Collins had actually said in the Met Office blog, which produced dozens of comments from people who totally disagreed with them. I must live a sheltered life because I never noticed all these shenanigans going on the time, and have only just noticed that Dame Julia had retired.

I’ll be back to revisit this reanalysis data when I’ve done a bit more development work…

Cold spell gone before it started

I have a theory that northerlies don’t last as long as they did in the past, the general life expectancy of one is probably no more than 48 hours tops. The cold from the current ‘Arctic blast’, has already moved south to allow warmer temperatures to come down from of all places the Arctic. It’s not evident until you run a comparison of temperatures differences that are 24 hours apart that you’re ever likely to notice it though (fig 1). I’m not saying that temperatures aren’t several degrees below average for this time of year, but it’s warmer 2 or 3°C warmer than it was at the same time yesterday over much of the north, and conversely it’s up to 7°C colder across many central  and southern areas.

Figure 1

This one is a polar low

The earlier low that’s now scooted off down the east coast of Scotland may not have been a proper polar low, but as I suspected might happen, the one that’s just south of Sule Skerry at 1600 UTC is. Figure 1 is not from a kindergarten by the way, it’s my attempt to draw up the 1600 UTC chart using my Wacom tablet, so excuse the state of the isolines, it’s very difficult to get any kind of smoothness or get your hand inside a radius to draw a curved isobar, but it’s the best I can do under the circumstances!

Figure 1

The circulation around the feature is clearly seen in this 1545 UTC visible satellite image (fig 2) with curl of cloud marking the associated trough that lies to the west of the polar low and stretches north-northwest from Stornoway.

Figure 2

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

BBC weather takeover imminent

The takeover of the BBC weather contract by MeteoGroup must be imminent if it’s to happen this spring as promised. I’ve read recently that Meteogroup are going to provide the graphics for the new service, and I wonder if they are of the same standard that they push out on their Twitter account. It seems that the Met Office are using all forms of social media including Twitter to show of their new graphics engine – Visual Cortex. If these couple of examples I have included from their respective Twitter accounts are anything to go by (figs 1 & 2), I think I much prefer the graphics and animations from the Met Office than those of MeteoGroup, which do look a little dated. Corporately, I think that the Met Office are still smarting after being dropped by the BBC, it’s quite obvious from how they’ve upped their game in the last couple of years on social media.

Figure 1 – Courtesy of MeteoGroup

Figure 2 – Courtesy of the Met Office

Of course MeteoGroup could surprise us, and have their own new bespoke graphics engine ready to go from the start, or maybe getting that in place and tweaked has delayed the takeover. It seems that all the various staffing changes concerning the presenters in London have now taken place, and all we are waiting for now is the big switchover.

SC at 5000 feet

Figure 1

At first I thought that this was low AC when I first saw it, which shows you what a poor observer of cloud I was in my day, but the LCBR at Exeter airport reckons the base is 5,000 feet, and I’m not going to argue with that. Feel free to tag on some extra supplementary varieties to the description such as undulatus, perlucidus (gaps between), or stratiformis.

Dry spell continues

The dry theme that started in late March continues into the last week of April, especially over central southern parts of England (where some stations are still in a state of partial drought), as this graph of precipitation illustrates from Benson in Oxfordshire since the start of this year (fig 1).

Figure 1

A big part of why it’s been so dry is the anticyclonic weather of the past month, as you can see from the Benson barograph (fig 2).

Figure 2

A state of type is now well under way, with cold air set to flood south across the country in a N or AN, but according to the latest NWP guidance that meridional type looks like it will be a relatively short-lived affair, before things become more mobile from Sunday, putting an end to the dry spell even across southern counties.

Sign of things to come at Baltasound

The cold air has dug back in behind the cold front at Baltasound, turning the rain to snow, as the low pressure whizzes across the Northern Isles.

I wish someone would sort out that anemometer at Torshavn, I’m sure that the wind direction is the exact reciprocal of what it should be, it’s happened before, you just can’t trust those AWS.

 

Eleven of the best NWP viewers on the Internet

If you, like me, are fascinated by what the weather is going to do in a bit finer detail than you’ll ever get from watching the weather on the BBC, then you might be interested in some of the eleven websites that I’ve listed below. They all provide a quick and easy way of looking at NWP forecast data from various models, usually the American GFS, but not always. There have recently been a rash of new websites providing these kind of viewers, and they are increasingly becoming more sophisticated and professional. I’ve tried to put them into some kind of ranking, let me know if you agree, or maybe you know of a website that I’ve missed out completely.

#11 – metvuw.com

A basic GFS viewer from James McGregor in New Zealand, the graphics and maps used are simple and clear once you find them, as are the controls and available map regions, all set in a web page that offers visualisation such as satellite, weather radar and observational data.

Figure 1

#10 – yr.no

The Norwegian Meteorological Institute and the Norwegian Broadcasting Organisation have put this NWP viewer together between them. It’s rather Norwegian centric, rather like the Met Office website is with the UK, and as far as I know it’s their own NWP model that they use. Personally I just like the Meteograms, which in my opinion would be even better if they ran out to T+120 or longer.

Figure 2 – Norwegian Meteorological Institute and the Norwegian Broadcasting Corporation. © 2013 – 2017

Figure 3 – Norwegian Meteorological Institute and the Norwegian Broadcasting Corporation. © 2013 – 2017

#9 – wetterzentrale.de

The Wetterzentrale site has been around for years and was recently was re-sited and the NWP viewer spruced up. I like the basic idea of the graphics that they produce, and the overlay of an MSLP field on top on a colour filled contoured chart of geopotential height seems to be a defacto standard. I also like the ability to access other models from around the world, especially the 20th century reanalysis data that the site provides as well. I think the controls are still a little bit basic and could do with a bit of a makeover.

Figure 4

#8 – ogimet.com

The OGIMET site is an old favourite of mine, and is were I go to download SYNOP data, and even though the guy that runs it has never replied to a single one of my emails over the years, it still displays a comprehensive array of GFS model data for various regions. I like the multi-layered graphics which are clean and simple, the functionality and controls are rather basic though.

Figure 5

#7 – theweatheroutlook.com

The weather outlook viewer controls are just a little bit more sophisticated than those on the wetterzentrale site, but the graphics are very similar. The controls make selection a little quicker, with flyover selection of model time steps by means of the mouse, with a good range of NWP data fields to access and display.

Figure 6

#6 – netweather.tv

The netweather site have a similar approach to that of weather outlook, but if anything the user interface is clearer and more organised. Again the NWP graphics are not that dissimilar to those produced by wetterzentrale and superbly clear.

Figure 7

#5 – tropicaltidbits.com

This site keeps a special eye on tropical cyclones, but that doesn’t stop them enabling their NWP viewer to be pointed at other regions from a variety of NWP models. The graphics offer multiple layers of NWP types which are sharp and clear, and you can view some quite sophisticated overlays on detailed outline maps.

Figure 8

#4 – earth.nullschool.net

The earth viewer from Cameron Beccario has been around for a long while now, but has exquisite animated graphics. The controls are hidden away so as to get the full effect of the viewer when running in full screen mode. What else can you say other than it’s just beautiful.

Figure 9 – © 2017 Cameron Beccario

#3 – windytv.com

The windytv viewer goes a little bit further than the earth viewer, and gives you an always visible interface, that’s not obtrusive and very tastefully designed, I bet behind the facade it probably uses the same vector graphics and mapping though. A really swish NWP viewer which I don’t use often enough.

Figure 10

#2 – ventusky.com

The ventusky viewer is from the same stable as the earth and windytv viewers by the looks of it. I quite like it, even with the slightly gaudy colours that they’ve chosen to use on their wind fields.

Figure 11

#1 – wxcharts.eu

The wxcharts viewer does just about everything that you could want of a NWP viewer in a web browser, and it must be the equal of many desktop weather visualization systems. It’s hard to believe that the developers have packed so much into the display, in which they’ve also managed to include meteograms as well as maps. You can tell that the team that’s put this together are real enthusiasts. The NWP graphics might be static, and not just quite as impressive as the animated maps from ventusky or windytv viewer, but I still think wxcharts as the edge on them in my opinion.

Figure 12



National Met service offerings in comparison

The DWD in Germany just like to keep it simple, why complicated things with those funny isolines and colour filled contours.

Figure 14 – Meteo France

Sophisticated stuff from the French, in this screenshot from the Meteo France website. I suppose for the general public this viewer is telling them all that they need to know – generally sunny.

Figure 15 – The UK Met Office

The Met Office are still using the same FAX charts that they’ve been using for the last 50 years or more, they analysis chart still has the same PPVA89 file designator that it’s always had, but at least nowadays it’s in colour. The Met Office have collaborated to produce the Visual Cortex graphics engine which they use on ITV and internally these days. They seem to have placed most of their effort into producing weather forecast videos which they use on their website and social media. It’s a shame that Visual Cortex can’t be used to provide NWP graphical output to a web viewer in a similar way to what ventusky have done, how hard can it be.

At least the Americans are now trying to update their viewers, and have recently started to use GIS web services offered by ESRI I notice.

It’s all very sad when you compare the quality and sophistication in the first eleven NWP viewers with those on offer from some of the worlds National Met Services. The difference is quite stark in most cases, it’s as if these organisations don’t even want to compete, after spending countless millions on the fastest supercomputers, and building the most sophisticated ensemble and deterministic NWP models, they just tire at the last hurdle and leave it to others to provide a web interface for the citizens of their respective countries to use, the question that springs to my mind is, why not?