With the El Niño–Southern Oscillation (ENSO) trending toward neutral I thought it would be interesting to see how east London’s climate has been affected over the past year.
Using the 12-month rolling mean for this station the difference is an increase of 0.24C. The increase in rainfall, using the 12-month rolling average, is more stark with an increase of 100.9mm.
I had a look at all other El Nino events back to the early 1960s. Some 5 of 7 events saw an increase in the rolling average mean.
The 12-month rolling average rainfall similarly saw an increase in 5 of the 7 events.
The most notable event was May 1997 to May 1998 which saw the temperature increase by 1.67C and a massive increase in rainfall of nearly 300mm.
Sections of the tabloid media have been going into overdrive these past couple of weeks with tales that the UK will soon be in the grip of an Arctic freeze – one headline in the Daily Express boasted that parts of the UK were in for FOUR MONTHS OF SNOW.
The Daily Express ‘forecast’ was published at the end of September
These stories are nothing new though they seem to be published earlier and earlier in the autumn. By the time we reach November – once the traditional time when winter forecasts started appearing – the tabloids have already turned their attentions to spring. Much of it is just ‘clickbait’ – a means for publishers to prove their stories are being read to keep their advertisers happy, a symptom of an industry in financial dire straits.
There will be snow somewhere in the UK during the next five months but predicting heavy snowfall in a given area, such as London, is impossible. But given the outrageous claims at such a long way from the start of the season on December 1st I decided to have a look to see if there is anything wintry on the horizon.
I started by comparing a range of historic datasets, including quasi-biennial oscillation (QBO) and el niño–southern oscillation (ENSO), against monthly mean temperature and rainfall anomalies. Because ENSO data only goes back to 1950 the findings are obviously far more restricted than my winter forecast method which uses local data going back to 1797.
The results of my data trawl are underwhelming. The best fit years were as follows:
For anyone who likes snow the above is not encouraging, however, given the past year which has seen several daily and monthly records shattered, including a record warm December, who’s to say that recent warm temperatures will suddenly swing the other way.
The above table would also suggest that the coming winter will be colder and snowier than the previous three – but that gives little away given how mild the past three winters have been.
October 2016 has seen a strong blocking high become established over Scandinavia, the earliest this has happened since 1881.
A study of mean temperature anomalies in London since 1950 suggest that sudden swings, both positive and negative, are becoming more likely. Last month was the fifth month in a row that I recorded a positive anomaly – the longer this goes on the more likely it is the mean could turn negative – though bear in mind that I have recorded 12 months in a row of positive anomalies, from February 2011 until January 2012.
Current weather also suggests that something maybe afoot with the earliest establishment of a strong anticyclone over Norway (the fabled Scandinavian high) since 1881! This weather pattern gives the south-east its best chance of snow with the feed of cold air often coming all the way from Siberia. Time and again, however, I’ve seen these patterns break down in November just as everyone starts talking about an imminent severe winter. There is more than an element of truth to the saying:
Ice in November to bear a duck, rest of winter will be slush and muck
In conclusion, while the early figures look bleak for snow in the low-lying south-east, it is still far too early to tell if the coming winter will be mild or cold.
I don’t usually bother trying to forecast autumn or spring given that there is far less interest in them than winter and summer. However, given the heightened interest in this year’s hurricane season and emboldened, perhaps foolishly, by my reasonably correct summer forecast I decided to have a look at the stats and see if I can find any signs where autumn in east London may be headed.
Using the method for my seasonal forecasts resulted in a shortlist of 26 summers that were similar to 2016.
Because the NOAA ENSO index only goes back to the 1950 I decided to disregard all years prior to this date to try to make any results more reliable. This narrowed down the list to 11 years.
With these considered I then searched for years that had a similar ENSO index to June (0.1 – neutral) with a tendency to turn negative (La Nina). This narrowed the field further to three years: 1999, 1992 and 1964. However, the only year that is showing signs of being similar with regard to where the ENSO index is forecast to be heading is 1964.
Although, so far, there has been an uptick in hurricane activity similar to 1964 there is, of course, the added consideration that Saharan dust is playing a part in impeding the formation of these tropical storms in the Gulf of Mexico – something the weather models seem to struggle to get a grip on.
With this in mind perhaps there will also be lower than usual instances of these storms crossing the Atlantic to affect the UK: hence a quiet autumn though, on a national scale, interpersed with the odd interest from the Atlantic. In London, perhaps we can expect something very similar to what is listed on the excellent website: http://www.london-weather.eu/article.103.html
od for my seasonal forecasts resulted in a shortlist of 26 summers that were similar to 2016.
In London, perhaps we can expect something very similar to what is listed on the excellent website: http://www.london-weather.eu/article.103.html
Wanstead Meteo 
You must be logged in to post a comment.