Tag Archives: London winter forecast

November 2016: record sunshine, cool

November 2016 was the sunniest in a record going back to 1881. Some 91 hours were recorded, 156 per cent above average and a complete contrast to last November which was the dullest for 47 years.

frost
The temperature in the early hours of the 30th fell to -6.1C, colder than any night last winter and the coldest since January 2013

The mean temperature for the month finished 6.4C, that’s 1.5C below the 1981-2010 average ; 4C cooler than last year and the coldest November since 2010. The warmest day occurred on the 15th with 15.9C recorded. The first air frosts of autumn were recorded. The lowest temperature occurred on the 29th when the spirit fell to -6.1C.

Rainfall was 135 per cent of average with 80.1mm recorded. The wettest day was on the 19th when 23.5mm of rain fell.

The sunniest days were on the 2nd, 13th and 25th when eight hours of sunshine were recorded.

Air frosts: 4, Ground frosts: 19

stingjet
The dolphin-shape of this radar image shows Storm Angus before it hit the south coast. The system stayed far enough south of us not to cause any damage in London

What has December got in store weatherwise? The models suggest the high pressure that has been anchored over us, bringing cold nights, will pull away to the continent. This will allow an ever milder but mostly dry source of air off the Atlantic through to mid month. Days will grow milder while frost and fog will feature less at night.

Beyond the grasp of the models my long range outlook method suggests an cold month is most likely at 43 per cent probability. Average comes in at 29 per cent probability while rather mild and rather cold are both 14 per cent probabilities.

Rainfall looks finely balanced. Wetter and dryer than average both come in at 43% probability while average is 14 per cent. Given the influence of high pressure at the beginning of the month I’m inclined to think it will be a drier than average month.

So, to sum up, we’re looking at a mean of 4.4C, rainfall: 55mm, sunshine: 39hrs.

My forecast last month was good: predicted mean 6.8C (result 6.4C). Rainfall: 55mm (result 80mm). Sunshine was way off, however – predicted total: 41hrs (result 91hrs)

I have also published a winter forecast covering the London area that you can find here.

Here follows the full weather diary for November…Full stats for the month here:http://1drv.ms/1rSfT7Y

1st: Cloudy and mild all day. Patchy drizzle at times.
2nd: Sunny, cold start after first ground frost of the autumn.
3rd: Sunny, cold start with cirrostratus and cumulus drifting around. Cloud thickened through the afternoon with some light rain around 9pm.
4th: Cloudy, dull start up to 11am. Rain pushed in and lasted for much of afternoon, clearing in evening.
5th: Cloudy, cold and damp start. Some brightness though with a cold wind.
6th: Sunny, cold start, tending to cloud in. Rain after 3pm. Feeling cold but too windy for a frost overnight.
7th: Sunny, cold and very breezy to start, the cloud tending to fill in through the day. Clearer overnight though too much cloud and occasional air prevented an air frost.
8th: Sunny and cold start. Cloud thickened during the day to bring rain after dark at 8pm that then fell through the night – the biggest fall since Brexit day.
9th: Light rain slowly clearing to cloud.
1oth: Cloudy start with light rain showers around 10.30am then cloudy. Some sunny intervals in the afternoon. Milder.
11th: Bright start with cloud decreasing through the morning to leave a pleasant and clear afternoon.
12th: Miserable and rainy to start, this lasting past 11.15am. Drizzle thereafter into 6pm.
13th: Sunny start though cloud tended to fill in through the day. Damp overnight with patchy drizzle.
14th: Cloudy and damp start with some breeze. Brief brightness at noon but patchy drizzle moved in around 4pm.
15th: Cloudy and miserable though very mild.
16th: Sunny start and very mild though cloud tended to fill in during the day making the sunshine milky.
17th: Bright, breezy start, the breeze increasing until a squall blew through at 2.40pm then sunny spells. front
18th: Bright start with milky sunshine then tending to cloud over. Feeling cold.
19th: Bright sunshine though cold to start. Patchy altocumulus developed through the day, leaving it to become bright, the strength of the sun diminishing. Rain started around 6pm and fell through night with varying intensity.
20th: Dull and cloudy start with rain returning at 10am. Cloudy afternoon with rain returning late evening and through the night, some heavier bursts.
21st: Cloudy with showers past noon. Heavier showers moved in mid afternoon and fell into the evening.
22nd: Cloudy with a few very light showers around. Breezy.
23rd: Cloudy and breezy. Feeling mild.
24th: Cloudy and mostly dull with brief brightness at noon.
25th: Sunny with just a few cumulus around.
26th: Sunny start but low cloud blotted out the sun around midday then cloudy and cool.
27th: Cloudy and mild.
28th Sunny all day with just a few cumulus floating around.
29th: Sunny all day with frost persisting on grass in shade.
30th: Sunny and very frosty start. Frost persisting on the grass all day with a very cold start to the night. A veil of cloud crossed the region late evening, lifting the temperature above freezing, before clearing before dawn

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London winter forecast 2016/17

Frost still lingers on my lawn as I write this winter forecast on the last day of the meteorological autumn. Last night’s minimum was -6.1C, the coldest night this year and, indeed, colder than any night last winter.

It would be very easy to get caught up in the hysteria that happens every November of what the winter will bring. Most of the hysteria comes from ‘coldies’, those folk that hope every winter will be the coldest and snowiest on record. I count myself among them.

screen-shot-2016-11-30-at-11-37-53
The north-west of England looks around 10C above average on December 9

But, despite hints from BBC weather forecasters that something maybe afoot in terms of something colder than usual from mid-December, years of disappointment have taught me to just take winter as it comes. Meteorological models this morning look anomalously warm for the first half of December, the UK being on the warm side of an anticyclone centred over France – the theme of so many winters I can remember.

The current phases of ENSO and QBO suggest that their influence on our winter this year will be far less marked than last year. Looking at teleconnections with a slight La Nina and the current QBO cycle have revealed winters that were fairly uninspiring though by no means write-offs for snow, two examples in the case of QBO being 1985/86 and 1990/91 – both had very cold Februaries.

Before I got too bogged down with trying to find patterns here I decided to move on to my more traditional pattern-matching.

Before I trawled through the figures my initial gut reaction to this winter was that it would be the coldest for at least four years – a not-too-difficult feat giving the mildness of the last three winters which saw very little in the way of snow.

winter201627The overall mean temperature for December, January and February came out at as 4.2C1.2colder than the 1981-2010 average, with average precipitation. 

rather cold winter, over three months doesn’t tell you much. A very mild and stormy December could mask a dry and notably cold February. This makes it worth looking at the individual months of each winter.      

december2016january2017february2017

There is a lot of spread in the above tables. Considering them altogether I would guess winter will unfold in the following way:

December to start mild, possibly becoming very mild, before beginning to turn very cold mid-month. This pattern will persist, with varying intensity through into January which could also be very cold. Milder conditions to follow in February though this will probably end a fairly average month and drier after a slightly wetter than average December and average January.

As well as my method of using rainfall and temperature I also considered other methods. One was Russian research that states that the weather pattern in the winter will be the opposite to the weather on September 17th and November 7th. This autumn September 17th was N’ly and November 7th was NNW’ly. So, this would suggest a continental flow from S and SSE.

You can read the method of how I reached my conclusion here.