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





Unsettled weather to come – but no repeat of ‘St Jude’ in sight

29 10 2013

There have been a few mentions in today’s media of another storm coming in for this weekend – with the Daily Express suggesting that a ‘new deadly storm’ is on the way.

It’s fair to say we are expecting a spell of unsettled autumnal weather over the next week, with some strong winds and heavy rain possible – but comparisons with the ‘St Jude’s Day storm’ (as some in the media have called it) are wide of the mark.

Currently forecasts suggest that we will see several low pressure systems affecting the country over the next week – which is a fairly typical picture for UK weather at this time of year.

These could bring gale force winds at times to some areas, but we don’t expect gusts to be anything like the exceptionally strong winds we saw on Monday. In fact, the winds are more likely to be similar to those we saw during the day last Sunday – the day before the big storm.

Of course, even gale force gusts do bring some risks and the Met Office will closely watch developments to assess any impacts.

The low pressure systems coming through over the next week are likely to lead to some rough seas and big waves around some coasts, as well as some heavy rain.

The Met Office, Environment Agency and Scottish Environment Protection Agency (SEPA) will be working together to monitor the risk of any impacts from these over the next few days.

Given the outlook for unsettled weather, we’d advise people to stay up to date with the latest forecasts and warnings from the Met Office and to sign up to receive free flood warnings from the Environment Agency and SEPA website.








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