I’m betting on a White Christmas…

Courtesy of William Hill’s

I would have thought that a £10 bet at odds of 10/3 for a White Christmas in Glasgow this year might well be worth it if the latest NWP forecast from the GFS model is anything to go by. If this forecast is right the air over Scotland will be of the sub 528 da variety, and there will be enough showers feeding into the west of Scotland in a strong to gale southwesterly to almost guarantee snow in the heavier ones, especially over any slightly higher ground. But don’t take this as an endorsement from me that you should go out a place a bet – these computer models, even at 192 hours, are changeable and fickle. I wonder who William Hill mean when they that the ‘Results confirmed by British Weather Services‘ ?

Courtesy of OGIMET

Fourth shortest melt season in Arctic

arctic-sea-ice-extent-7-november-2015-30-september-2016

Rather bizarrely the melt season in the Arctic was the fourth shortest in the Sea Ice data series that started in 1979. As you can see from the above chart, the melt started on March 21st of this year and ended on the 7th of September, which made the melt season 169 days long, the shortest since the 166 days of 1997. The short season is down not just to a very late maximum, but also an early minimum, but why that should occur in a season that saw the second lowest maximum is slightly puzzling.  The spring maximum was 13 days later than average, and the autumn minimum was 4 days early than average.

arctic-sea-ice-melt-season-1980-2016

Here’s a ranked list of the shortest melt season in the Arctic.

arctic-sea-ice-extent-1979-2016

In the Antarctic as you can see there has been a  lengthening of the freeze season by 6 days and a reduction of the melt season by 11 days since 1980.

antarctic-sea-ice-melt-season-1980-2016

 I will warn you now, that I use the daily values from the series in my stats, and not the trailing five-day mean which the National Snow and Ice data Centre [NSIDC] have recently switched to, although I shouldn’t imagine that would have made much difference.

It’s Top of the Hots!

maximum-temperature-c-1800-utc-on-tue-13-sep-2016

Earlier this week I had a look at the recent hot September day on the 13th, and particularly at Gravesend-Broadness (WMO #03784) were the record of 34.4°C was set. I said in that article that to me Gravesend was one of the most unlikely hotspots that there could be situated as it is in the Swanscombe marshes, jutting out into the Thames on Broadness, that mud has a lot to answer for. It appears so regularly in the warmest places in the country it won’t be long before it has its own Facebook group and throngs of Japanese tourists trudging round it to pay homage. Anyway I thought I would do a little more investigating and find out just which station was at the number one spot in the Top of the Hots hit parade so far in 2016.

capture2

Courtesy of Bing Maps and the Ordnance Survey

And at number one, the warmest place in the British Isles is Gravesend with a massive 29 days! In second place the title holder for many years but now usurped by Gravesend, that old-time favourite London Heathrow with 22 days. The south-east of England has the greatest proportion of warm days as you would probably guess with St James Park in joint 4th place with 12 days, Northolt in 7th place with 10 days and Manston in 10th place with 7 days.  I make that approximately 80 out of the 261 warmest days occurred in the southeast this year.

warmest-place-by-day-in-the-british-isles-1-january-2016-18-september-2016

Here’s a look at the maximum temperature of each day this year from block #03 of the SYNOP observations. The bars are marked to indicate when Gravesend was the warmest place and the maximum temperature for that day. There is a proviso with these stats, and that is I have only allowed one maximum for each day, so if there was a joint highest the station with the highest WMO number will get it, I will revisit the code and fix that when time permits.

warmest-day-in-the-british-isles-highest-max-06-18-1-january-2016-18-september-2016

How summer 2016 is doing so far

In Central England the mean temperature of the Summer [JJA] so far is 1°C above the long-term average, which currently makes it the 17th warmest of the last 138 summers for the period from 1 June to 22 July. So pretty warm, but not in the same league as 1976 or 2003 for the same time, but of course there is still almost six weeks left to run of the meteorological summer and August might be a sizzler! Below is a chart comparing maximum temperatures of 2016 with the summer of 1976 forty years before, of course the data for July is still provisional but there’s still no missing the recent hot day of Tuesday the 19th. The way the anomalies for this summer are currently (maximum +0.71°C minimum +1.35°C) it points to warm nights being the main driver rather than warm days, in fact maximums ran below average for much of the period between the 24th of June and 15th of July.

Daily Central England Temperature Warmest start to a Summer [JJA] 1878 - 2016

Daily Central England Temperature  – Warmest start to a Summer [JJA] 1878 – 2016

Days of thunder

Accumulated Precipitation for 0600 UTC 1 January

Days of Thunder 1 Jan –  26th June 1016

It’s very difficult, I would say impossible to find the latest detailed statistics on thunder across the UK, let alone across Europe and other parts of the world. The obvious answer would be to generate monthly frequency maps from the output of the Blitzortung lightning system, but I am not a member, and even if I were it may still not be possible to get my hands on the data to do this with. Despite all this, I have come up with a simple and very effective method of compiling ‘days of thunder’ from SYNOP observations. It depends on the present weather code [WW] and the past weather codes [six hourly ww1 & ww2 code from the main synoptic hours] and the fact that thunderstorms have such high priority there are reported above any other present or past weather codes. So it’s simply a case of writing some software to count any thunderstorms that are reported in any of the SYNOP observations. There is one problem, and it’s a very big problem nowadays, and that is automatic observations which make up as many as 90% of SYNOP observations in countries such as the UK, don’t report thunderstorms as far as I can see (although there may be exceptions – it’s a big world). That’s why when you look at the maps that I’ve produced you will see a lot of spurious zero values plotted. It’s easy to work out an automatic observation in the UK & Ireland, but not so in some other countries such as France, in time I may be to winkle out all the automatic like this, but for the moment they are included.

Anyway the top map is of days of thunder for the 1st of January to the 26th of June, and as you can Erzincan in northeast Turkey is top of the European list with 40 days of thunder, in comparison Brize Norton in Oxfordshire with 9 days is top of the available manual stations in the UK. A quick look at America and the Caribbean reveals that David in Panama is top of the list there with 58 days of thunder so far this year. Tampa has only 1 day because the observations are missing for a good deal of the time. Hopefully with a little more polish, the output from this application might be a little less ambiguous the next time you see it, for now its work in progress!

2016 certainly seems to have been a very thundery year so far, but I would have to do an awful lot more data processing to calculate a thirty year mean for a great many stations before I could say it is. At one time the Met Office published an hourly text bulletin of sferics across Europe [SFUK26], but over 10 years ago they stopped issuing it which was a big pity. The more frequent and more detailed high-resolution bulletin which replaced it [SFUK27] may still be being produced but was never made public on the internet, which is another great pity. Thank goodness for the Blitzortung organisation who had the foresight to see the importance of monitoring lightning from thunderstorms and making it freely available to all, something I thought that national weather services were supposed to do.

Days of Thunder for 1 January - 27 June 2016

Days of Thunder for 1 January – 26 June 2016

Hurricane predictions 2016

The predictions for how the forthcoming 2016 North Atlantic hurricane season will turn out are now in, and as you can see from the info-graphics below, I’ve managed to find three predictions from:

All the predictions look remarkably similar to my eye. It might be that my 1851-2015 statistics are much lower than there’s (which may well be because they are based on the 1981-2010 long-term average), but I would say that they are all predicting well above average totals for 2016.

My prediction for what it’s worth…

Even though El Nino is ending, I would have still thought that because 2016 already seems to be on course to become the warmest year on record globally, and even warmer than 2015, and because sea surface temperatures are closely linked to this, there should potentially be a lot more extra energy available in all the oceans of the world (with the exception of the Pacific) for tropical cyclone development. So just for the hell of it I’m going for a well above average year for 2016 in the Atlantic, and very similar to 2010.

AccuWeather

Accuwaether 2016 Hurricane Prediction

Accuweather 2016 Hurricane Prediction

UK Met Office

Met Office Hurricane Prediction 2016

Met Office Hurricane Prediction 2016

Met Office Tropical Storm Prediction 2016

Met Office Tropical Storm Prediction 2016

NOAA

NOAA North Atlantic Hurricane Prediction 2016

NOAA North Atlantic Hurricane Prediction 2016