Up to 2, people drowned around the Bristol Channel in , the greatest loss of life from a natural catastrophe in the UK in the last years.
A family evacuated in Whitstable, Kent, during the 'Great Storm' of These floods killed people in eastern England and were the catalyst for the construction of the Thames Barrier.
In , a severe storm washed away the lowest street of houses in the village of Brighthelmstone today's Brighton. Daniel Defoe, the author of Robinson Crusoe, wrote an interesting account of the events in The Storm. He described the aftermath of the flood as "the very picture of desolation" and wrote that "it looked as if an enemy had sacked" the towns affected. The worst natural disaster to affect the UK in modern times was the 'Big Flood' of early This was the driving force for the creation of the Thames Storm Surge Barrier and other flood defence schemes around the country.
Today, this provides warnings of impending high sea levels, helping people prepare for flooding emergencies. On several occasions the government assembled the Cobra crisis committee. Particular events stand out. First, the storm on December that generated what was widely referred to as "the biggest storm surge for 60 years" and flooded 2, homes and 1, businesses.
Second, the storm in early February that destroyed the Dawlish railway in Devon. Third, the dramatic 'Valentine's Day Storm', which placed the south coast under severe flood alert. The fact that the damage was so limited during these storms, compared to the tragedy of , is thanks to significant government investment in coastal defences, flood forecasting, sea-level monitoring and improved communications.
On top of this, there is currently no nationwide system in place to record which high sea levels caused coastal flooding, and to record information on how often this happens and what the consequences are. This limits our ability to understand coastal flood risks and makes it difficult to assess how unusual really was. We compiled data on the 96 largest events over this period, with information on the storm that generated each event, the high water levels recorded during the events and the severity of coastal flooding.
We also developed a website to make the information freely and easily accessible to a wide range of users including scientists, coastal engineers, managers and planners. We are aiming to expand the database and are appealing for the help of the general public. Do you have any photographs of coastal flooding from recent or past events which you are willing to share? Photos can be easily uploaded to the SurgeWatch website - external link.
We want to investigate these in order to improve understanding of exactly which areas were flooded and to what water depth. Please don't put yourself at risk to take photos, though. It is useful for evaluation of the meteorological uncertainties involved in the forecast and how well these are captured by the ensemble.
The observations show the true observed surge prior to quality control. Overall the surge ensemble performance for this December event was very good.
The risk level on the FGS was elevated as confidence and foreseen impacts increased, becoming Red high likelihood of severe impacts for the East Anglia coast by utc on 5 December.
At short range the surge ensemble and deterministic surge models gave useful guidance for most ports, with the ensemble continuing to add value to the deterministic model by enhancing confidence and giving the range of surge levels still possible at this lead time.
Responders on the ground activated their emergency response plans, closed flood defences and evacuated vulnerable communities, all resulting in a reduced risk of damage to life and property. Comparing the December event with January The December events correlate reasonably well with those of However, the low centre of the event turned southeastward as it deepened in the North Sea Prichard, , while the low pressure continued eastwards into Scandinavia Figure 1. However, with the system, subsequent troughs of low pressure can be seen running southwards down the North Sea as the gradient wind flow veered towards a more northerly direction, and severe gales and storms were reported at sea.
The event took 48 h to cover a similar distance, but with a very strong northerly flow in the North Sea it is estimated that maximum wave heights correlated well with the time of high tide and surge Wolf and Flather, Maximum mean wind speeds and wave heights correlate reasonably well between the two events.
Measured wave heights were 8—10 m over the open sea in the December event, with wind speeds in excess of 50kn in places. Records of wave heights are not as easy to gather and assess with the event. The December surge water levels were higher than those of the storm surge in more northern locations, but possibly slightly less further south.
However, due to damage to gauges in some of the data has been interpolated Rossiter, North Shields gauge, operational since , recorded 3. At Lowestoft in the OD N was 3. Calculating return periods for total water level is problematic due to several variables, including time and height of the surge and variations in astronomical tides, but many ports recorded their highest water level for over 50 years in Table 1.
The return period for the surge component at Lowestoft is estimated to be around 50 years, although rising sea levels will likely reduce the return period in coming decades Wolf and Flather, Sea levels around the coast of England and Wales are slowly rising from isostatic and eustatic adjustments i. Between and the Newlyn annual mean sea level rose by Over deaths occurred with the flood event in eastern England, and over deaths in the Netherlands Wolf and Flather, Following the disaster, effective monitoring, forecasting and warning systems were put into place, together with significant investments in North Sea flood defences.
Hundreds of thousands of properties and around km2 of agricultural land are now protected, including by the Hull and Thames Barriers. Early warnings of the event by the FFC, EA and NRW, and excellent planning by regional responders, meant that despite significant coastal flooding, no fatalities occurred as a direct result of flooding.
The surge and swell waves were developed by rapidly deepening and fast moving Atlantic low pressure systems. These low pressure centres were unusually deep and maintained an unusually low latitudinal track. The following discussion will focus upon four Atlantic storm systems that led to the most significant storm surges and wave action, with damaging coastal flooding along the west and south coast of Britain. See Kendon and McCarthy , this issue, for information about other events and impacts during the period.
Wave heights were reported in excess of 6 m on the evening of 3 January at Aberporth Buoy, and nearly 6 m at the Bristol Channel Buoy, with wave periods increasing to 15—20s the next morning Figure 3. Record total water levels were seen at many ports in western Britain Table 1 , with the surge coinciding with a perigee new moon spring tide. Fears of coastal flooding from the storm surge at Newport and other parts of the Severn estuary led to some evacuations.
An ancient pier at Lamorna Quay, near Penzance in Cornwall, was damaged as granite stones were moved by the force of the waves. Showing: top peak direction; centre Tpeak, the dominant wave period in seconds there are gaps in the data ; and bottom the significant wave height the mean height of the highest third of waves.
The warm sector ran well ahead of the low pressure centre and crossed the UK on the 5 January with severe gales or storms ahead of the surface cold front.
Very large waves were again reported breaking against the coast of West Wales and Cornwall, with flooding from the storm surge and wave action for instance in Bude and Aberystwyth, and also parts of Northern Ireland and Scotland. Several people were caught unaware and swept off rocks by the unusual wave action over the period, and coastal railway lines in North Wales and northwest England were damaged.
Spectacular waves were reported during the period, for instance breaking over cliffs at Sennen Cove in Cornwall. At Chiswell in Portland warnings were sounded on the Monday night 6 January as swell waves broke over the beach. The Wavenet Buoy in Poole Bay reported wave heights in excess of 4 m and a period of 20s. Shingle was rapidly degraded by the waves, making the town more vulnerable to subsequent coastal flooding events. A new record maximum water level of 3. Figure 5 Coastal flooding at Salcombe water front at high tide 3 February Damage occurs here periodically, but the length of track undermined and period of disruption was unusual; other recent occurrences of this nature include those of 11 February , 26 February , and 27 October Network Rail, Dawlish wave buoy reported a maximum wave height of 5.
Significant wave heights increased to around 4 m with a period of 8—10s. In comparison, the Met Office wave model forecast a peak of around 9. Wave models generally performed well during this period in open water, although with some differences nearer to shore.
During this period the harbour gate at Porthleven was breached, which led to several boats sinking. A number of coastal towns saw large waves break over sea defences see inside front cover.
Storm surges were experienced in several river estuaries, for instance on the Exe and Axe rivers, with Exmouth and Topsham flooded. Eyewitness testimony from sources at Topsham Museum suggests the flooding in the town exceeded the levels and was the worst since at least although prior to flooding also resulted from poor drainage.
This was very close to the later observation. In Datchet, Princes William and Harry were seen helping out with defenses at a local private school after its pupils were forced to relocate for months at a nearby hotel.
Showing: top peak direction; centre Tpeak, the dominant wave period in seconds there are gaps in the data ; and bottom the significant wave height the mean height of the highest third of waves. Please don't put yourself at risk to take photos, though. Shingle was rapidly degraded by the waves, making the town more vulnerable to subsequent coastal flooding events. With the January events, damage from the storm surge was enhanced by long period, high energy waves that developed in the Atlantic and were driven ashore by southwesterly storms. Photos can be easily uploaded to the SurgeWatch website - external link.
On several occasions the government assembled the Cobra crisis committee. Coastal flooding happens because of a combination of high tides, storm surges and waves. The December surge water levels were higher than those of the storm surge in more northern locations, but possibly slightly less further south.
The following discussion will focus upon four Atlantic storm systems that led to the most significant storm surges and wave action, with damaging coastal flooding along the west and south coast of Britain. Several hundred homes were evacuated in Kent, with risk of flooding in Sandwich and Seasalter. With erosion to coastal cliffs a number of dwellings were undermined as cliffs collapsed, for instance near Hemsby, Norfolk where a lifeboat station was destroyed. The village of Thorney was abandoned and Muchelney cut off.