The Great Storm of 1987 – 30 years on

After the devastating effects of Storms Harvey, Irma and Maria on the US and Caribbean Islands, we revisit the great storm of October 1987.  Experts are already saying that Storms Harvey, Irma and Maria could end up being three of the costliest storms in modern times. AIR Worldwide has put potential insured losses for the three storms in total at an astonishing $155bn. We are lucky in the UK that we don’t get storms of this type hitting our shores. Indeed, major storms causing losses in excess of £1bn are rare events in the UK. On the 16th October 2017, it will be thirty years on from the Great Storm of 1987.

Referred to in the industry as ‘87-J’, the storm took everyone by surprise and at the time, was classed as the UK’s worst storm since 1703. It still remains one of the most severe and costliest windstorms the UK has ever experienced. One in six households made a claim at the time and losses to the industry for commercial and residential cover exceeded £1.3bn.

Striking in the middle of the night, the 1 in 200-year storm left behind a trail of damage and devastation in the South East of England and Northern France with 18 people losing their lives and extensive damage to property and infrastructure. Many houses were without power for several days and fallen trees blocked roads and caused travel chaos. An estimated 15 million trees were uprooted and Seven Oaks famously became One Oak.

The worst affected areas were parts of Greater London, the Home Counties and the East of England. The South East of England experienced unusually strong wind gusts in excess of 81 mph lasting for 3 to 4 hours and gusts of up to 122 mph were recorded at Gorleston, Norfolk.

The exact path and severity of the storm were very difficult to predict using the forecasting methods and data available at the time.  The Met Office’s Michael Fish faced a backlash for dismissing a viewer who had asked about whether the UK could expect a hurricane but at the time it was hard to forecast the precise path the storm would take. The path of the storm and the direction of the wind were very unusual; running from south to north, with the storm striking the more densely populated areas of the South of England.  The South of England has higher concentrations of sums insured and this resulted in a large loss for the Insurance Industry. Subsequently, changes were made to the way forecasts are produced and the National Severe Weather Warning Service was created.

A better insight into windstorm risk

Data modelling and analytical tools to help underwrite and price property risks accurately for natural perils have come a long way since 1987 when data on individual properties was scarce and geographic risk assessed by postal district. Insurers are now much better equipped to gain an in-depth understanding of risk exposure with access to risk models that are based on up-to-date, accurate information and that take account of changing risk patterns.

Business Insight’s ‘Storm Insight’ risk rating model. is based on extensive research, huge volumes of explanatory input data and cutting-edge analytical techniques. Storm Insight utilises the largest source of storm claims information available in the UK, detailed property vulnerability data for every street and over 100 million historic windspeed data points recorded in urban areas across the UK.  We also have access to an archive of actual storm event footprints over the last 150 years to gain insight into rare events such as the 87-J Storm.

What would the industry loss be if 87-J were to happen again?

In 1987 the losses from the great storm on 17th October resulted in over £1 billion in insured losses to domestic property as well as significant damage to commercial property. Things have moved on since then, in terms of housing development, levels of affluence and insured values at risk. Over the last 30 years, there have been significant increases in housing development across the South of England in areas that were in the path of the storm in 1987.

Official figures from ONS show the number of residential properties in England increased by 28% between 1987 and 2017. In London (Outer and Inner) the increase has been 32%. Coupled with that inflation has more than doubled over the last thirty years and, perhaps more significantly, the wealth across the South East of England and London has increased enormously. Many more properties across the housing stock have been extended in 2017 compared with 1987 and the total insured values at risk is of an order of magnitude higher. The level of wealth is also far higher with one in ten households now reported as having assets worth more a £1 million.

If the UK were to encounter the same storm again in October 2017, the loss to the UK Insurance Industry would not be in the same league as recently reported losses in the USA and Caribbean though it would still break all previous UK records. In our view, it is likely that losses to the UK insurance industry for such an event would exceed £6bn.