UK’s exceptional weather in context

6 02 2014

As the UK’s run of exceptionally wet and stormy weather continues, the Met Office’s National Climate Information Centre has looked at how the last two months compare in the historical records.

Here’s some facts and figures for the weather we’ve seen through December and January:

For the UK

  • For the UK, December was provisionally the equal-fifth wettest December in the national series dating back to 1910 and January was the third wettest January in the same record. When the two months are combined, it is provisionally the wettest December and January in the series.
  • There were more days of rain (any day with more than 1mm of rainfall) for the UK in January than for any other month in a series dating back to 1961, with 23 days.
  • It was the windiest December for the UK in records back to 1969, based on the occurrence of winds in excess 60 kts (69mph).

England and Wales

  • Looking at the England and Wales Precipitation series, which dates back to 1766, it has been the wettest December to January since 1876/1877 and the 2nd wettest overall in the series.

Scotland

  • December was the wettest calendar month on record for Scotland in the series to 1910.
  • For eastern Scotland, December and January combined was provisionally the wettest two month (any-month) period in the same series.

Southern England

  • There have been very few dry days in this area since 12 December and regional statistics suggest that this is one of, if not the most, exceptional periods of winter rainfall in at least 248 years.
  • Despite the rainfall being concentrated in the second half of the month it was the wettest December for south east England since 1959.
  • January was the wettest January for the south England region in the national series dating back to 1910, and the wettest calendar month for the south east region in the same series by a huge margin.
  • The two-month total of 372.2mm for the southeast and central southern England region is the wettest any 2-month period in the series from 1910 .
  • From 12th December to 31st January parts of south England recorded over five months worth of rainfall (based on average January rainfall for the region).

You can see more statistics on recent weather and through the historical records on our UK climate pages.

Full month provisional statistics from January 2014:

Mean Temperature Sunshine hours Rainfall  
January
Actual Diff from Avg Actual % of Avg Actual % of Avg
  degC degC hours % mm %
UK 4.8 1.1 44.8 95 183.8 151
England 5.4 1.3 57.3 106 158.2 191
Wales 5.3 1.2 38.0 78 269.0 171
Scotland 3.5 0.9 27.2 76 205.3 116
N Ireland 4.5 0.3 37.3 84 170.7 147




How powerful was Monday’s storm?

30 10 2013

The storm that swept across southern parts of the UK caused widespread disruption and included a gust of almost 100mph, but how does it compare to previous storms?

It’s not just the numbers

In terms of the severity of the winds, you don’t have to go far back to find a more powerful storm than this – in January 2012 we saw winds of over 100mph in Edinburgh for example.

There are two things that made this storm so significant. Firstly, the timing – arriving in October when the trees are in full leaf and therefore much more vulnerable to strong winds.

Secondly the track of this storm was key. Along the northern and western coasts of Scotland and northern Ireland winds of 70-80mph are not that exceptional because they are on the more usual track of Atlantic storms.

However, powerful Atlantic storms are seen much more rarely across southern parts of England and Wales – which means these areas are much more susceptible to strong winds.

All this combined meant that the storm had a significant impact – with fallen trees causing the majority of disruption.

Satellite image showing the storm tracking across the UK

Satellite image showing the storm tracking across the UK

When did we last see a storm like this?

With that in mind, to find a similar storm we’d have to look at those which affected southern parts of England at a time when leaves are still on the trees (likely to be autumn).

To find a storm of similar strength that fits these criteria you’d have to go back to 27 October 2002. That storm brought winds of similar, or higher speeds, affecting most of England and Wales, and leading to widespread impacts.

Where does Monday’s storm rank in the longer term records?

There are many different ways of comparing storms – from looking at the strongest gusts, to mean wind speeds, to the area affected or the severity of impacts.

The Met Office National Climate Information Centre (NCIC) looked at autumn storms in southern England over the past 40 years, analysing the number of weather stations across the region which recorded a gust of 60 knots (69mph) or more for each storm.

From this they put together the ranking below which suggests Monday’s storm was within the top 10 most powerful autumn storms in southern England in the past 40 years.

The storm of October 2002 comes top of this ranking – followed by the ‘Great Storm’ of 16 October 1987.

Mike Kendon, from the NCIC, said: “This is just one technique for analysing storms and doesn’t necessarily tell us how severe an impact any particular storm had. On 16 October 1987, the maximum gusts we saw were much more powerful than those seen in 2002, and it was those very powerful winds – of up to 115mph – which caused the majority of the damage.

“What our analysis does tell us is that Monday’s storm was certainly one of the most significant autumn storms for at least a decade in terms of its strength and its impacts – even if it’s not on a par with some of the most powerful or damaging storms we have seen in the UK’s historical records.”

DATE OF STORM

STATIONS WITH >69MPH GUST

27/10/2002

36

16/10/1987

28

28/10/1996

24

30/10/2000

21

11/11/1977

18

28/10/1989

18

28/10/2013

16

07/09/1974

14

24/10/1998

14

14/11/1977

13








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