Agenda item

(1)          Mark Rogers from the Met Office gave a presentation. The accompanying slides are contained within the electronic agenda papers on the KCC website. 

(2)        Mr Rogers introduced himself as the Met Office Advisor for Civil Contingencies.  He worked with Category 1 and 2 Responders as defined by the Civil Contingencies Act 2004 in South East England (Kent Sussex, Surrey, Hampshire, Isle of Wight and Thames Valley).  

(3)       Mr Rogers said that the National Severe Weather Warning Service (NSWWS) had been set up in 1988 after the hurricane of the previous year.   Its original form had been as a threshold-based service. Warnings were issued when severe weather was expected with winds speeds reaching 70 mph or 30 mm of rainfall were anticipated.  This approach had ignored the wider impact of severe weather.  Its weakness therefore was that there was no policy differentiation between a 70mph wind speed in Scotland and South East of England despite the greater impact. 

(4)       In 2011, following a period of consultation with Emergency Responders, the NSWWS had developed an impact-based approach where the decision on whether to issue Warnings was based on the likely dangers and disruptions caused.  The UK was currently the only country in the World operating this system, although a number of countries were now considering doing so after receiving training from the Met Office. 

(5)       Mr Rogers said that the Met Office had issued Warnings for rain, wind, snow, ice and fog since the formation of the NSWWS.  Recently, they had added lightning and thunderstorms.  Warnings could now be given seven days ahead of the event.   Warnings for thunderstorms had previously been given under the “rain” heading.  By specifically warning of likely thunderstorms, the Met Office could now incorporate rain, hail, lightning and strong winds.   Warnings for lightning were also particularly important because of its impact on railways and power supplies.  

(6)       Mr Rogers continued by saying that an Impact Matrix had been introduced in 2011 to complement the new impact-based Warning system.  This enabled an accurate assessment by setting the likelihood of an impact occurring against the level of impact expected.    This enabled the allocation of a colour to the Warning (green yellow, amber or red).   The colour was, however, not all-important.   For example, if the box ticked indicated a high likelihood of a low impact event, it required different planning and response to a very low likelihood of a high impact, which would indicate potential danger to life, although a forecast was not at that stage suggesting that it was imminent.  Were it to become so, the risk could easily be upgraded to amber. An example of this had occurred during the St Jude’s Day storm in October 2013.   The Warning had initially been given when the likelihood had been very low.  The Warning had then moved up to “low” and “medium” likelihood of a high impact event.

(7)       Mr Rogers went on to show examples of how Warnings were issued.   They were placed on the Met Office website and on the Met Office App, which enabled people to sign up to receive them.  They were usually issued in pdf form and explained the nature of the event, its likelihood and potential impact as well as the area covered by the Warning and its duration.  The Warnings gave headlines on what could be expected and displayed the matrix.  

(8)       Mr Rogers moved on to explain how uncertainty was dealt with.  The Chief Forecaster, who was based in Essex, monitored model information gathered not only in the UK but also that from other countries such as France, Germany, Japan and the USA.   If all the models were giving similar outputs, it would indicate a high level of certainty. If, on the other hand, they were producing varying results, the level of certainty would be low.   Usually, but not always, the models would show more harmony as the event drew closer. 

(9)       Mr Rogers then gave an example. He showed a model which indicated a track of low pressure across central Southern England with the strongest winds occurring in the South East.  If this were the only model, the Met Office would issue a Warning for the medium likelihood of a medium impact event in that part of the country.  However, a second model was indicating a track further northwest across Wales with the strongest winds across western and into Northern England.   The Met Office would deal with the conflicting models by increasing the size of the area covered by the Warning whilst reducing the likelihood of the event to “low.” 

(10)     Mr Rogers said that another significant part of the NSWWS’ role was assessing the risk.  This involved identifying the location (rural, urban or coastal), considering the current conditions, including whether there had already been a lot of rain in the location, whether there was capacity in the reservoirs and rivers to cope with the event or whether the ground was so hard after several weeks without moisture that heavy rain would run off and increase the risk of flooding.   Another consideration was the time of year. The impact of heavy rain in the Autumn would lead to greater problems in that the drains and rivers were likely to be blocked by falling leaves.   Strong winds in the Summer were more serious than in the Winter because trees were in leaf and vulnerable camp sites, caravan and mobile home parks were more likely to be populated.   The time of day was also very important as the impact would be greater during busy periods for travel.

(11)     Mr Rogers turned to the Flood Guidance Statement which was created by the Flood Forecasting Centre, set up in 2009 following the Pitt recommendations.  The Flood Forecasting Centre was a joint unit involving the Met Office and the Environment Agency.   Its purpose was to forecast the risk of flooding over the next five days (covering river, surface water, groundwater and coastal flooding).  It issued the Flood Guidance Statement daily, using the colours green, yellow, amber and red and setting out whether the risk was decreasing, steady or increasing.  It also gave a run down and identified areas of concern. 

(12)     Mr Rogers moved on to the topic of Climate Change.   This was analysed through numerous computer models, using different information, which were sorted by the main computer in Exeter before being sorted into groups.   The top and bottom 10% probabilities differed markedly from the rest.  Mr Rogers showed the UK Climate Projections which had been completed in 2009.   The latest version for 2018 was still at the verification stage and would be ready by the end of the year.   Three different projections had been produced, envisaging a lower emissions scenario, a medium emissions scenario and a high emissions scenario for 2020, 2050 and 2080.   Mr Rogers showed the medium emissions scenario for summer rainfall which, at worst, was projected by most computers to drop by 20 to 30%, whereas the top 10% predicted a rise in rainfall of 10%.    For winter precipitation, the bottom 10% of the computers predicted an increase of 10% whereas the top 10% predicted a rise of 30 to 40%.  Although the evidence was complex, the likelihood was that by 2050 rainfall would reduce considerably in the summer and rise significantly in the winter – if the medium emissions projections (which were themselves considered to be a conservative estimate) proved to be correct.

(13)     Mr Rogers summarised the summer convection findings at the Met Office Hadley Centre by saying that although summers were likely to become drier by 2100, rainfall would be heavier and in short outbreaks, potentially causing more occurrences of serious flash flooding.  This was because the warmer summers in the UK became, the more water would be held in the warm air, leading to storms becoming more violent.

(14)     Mr Rogers said that the Met Office had published innovative research in 2017.  This had found that in England and Wales there was a 1 in 3 chance of a new monthly rainfall record in at least one region each winter.   Met Office records showed that since 1910 there had been 17 record breaking rainfall months or seasons and that 9 of these had occurred since 2000. 

(15)     Mr Rogers summarised the climate change section of his presentation by saying that its impacts on rainfall were complex and uncertain.  There was a greater risk of summer surface water flooding due to more intense rainfall. There was also likely to be an increase in winter rainfall which would lead to a greater risk of river and groundwater flooding.  A risk management approach was needed due to the continuing uncertainty.

(16)     Mr Bowles said that recent heavy surface water flooding had led to houses being evacuated in 4 of the 23 villages in his Swale division.  This was because water on the scarp of the Downs had run off the fields very quickly whilst the roads towards the North Kent Coastal Plain had taken on the form of rivers and the drains were unable to cope.   The ability to ensure that the drains were unblocked was well below satisfactory.  If serious action was not taken to maintain and clear the drains, there would be severe flooding every time there was heavy rain (which Mr Rogers had predicted would become a more regular occurrence in the future).  There was a risk that the County Council would be failing in its duty if it did not increase its efforts to clean out drains and gullies.  

(17)      The Chairman suggested that the concerns expressed by Mr Bowles could be dealt with by reference to the Environment, Transport and Waste Cabinet Committee in the light of the expert advice given during the presentation.  

(18)     Mr Rogers replied to a question from the Chairman on the joint working between the Met Office and the Environment Agency. He said that for short term work such as the Flood Forecasting Centre, the Met Office’s main role was to forecast the weather whilst the Environment Agency would use its computerised information about local conditions to identify the areas at risk of flooding and the likely impact upon them.  This enabled the daily Flood Guidance Statement to be as accurate as possible.  In respect of the long-term effects of Climate Change, the Met Office provided the Environment Agency with its modelling of future rainfall, and the Agency then carried out its own modelling around the information provided.

(19)     Mrs Brown said that KALC had been told that only those areas at most risk of severe flooding would experience an annual clearance of its gullies and that everywhere else would just be reactive.  In Yalding, there was a gully that had been blocked for three years.  The clearing work was described on the portal as having been completed, even though this was not the case.   When this was queried, it had been explained that the term “clearance” simply meant that it the work had been allocated.  The system was not working because three months after the notified clearance had taken place, the gully was still blocked, and no effort had been made to unblock it.  She suggested that the question of the upkeep of the portal was one which could be covered at the Environment and Transport Cabinet Committee. 

(20)     Mr Rayner asked about tidal flooding.  He referred to the February 1953 tidal flooding event where high spring tides had been effectively forced into the North Sea by low pressure before impacting South East England and the Low Countries.  Mr Rogers replied that the Met Office undertook tidal forecasts which took account of winds and pressure levels. This information was sent to the Environment Agency who used it to carry out the flooding forecast for the East Coast. 

(21)     Mrs Doyle asked about the level of international agreement on climate change modelling.   Mr Rogers replied that every country was a member of the World Meteorological Organisation which shared modelling and forecasts.   Most countries were also members of the International Panel on Climate Change whose scientists considered all the modelling so that they could develop an international view.   There was consequently a general convergence of views, although some scientists did take a different view.  

(22)     Mr Lewin asked how the data prepared was used by the Insurance Industry.    Mr Rogers said that he was aware that Insurance Companies used Met Office projections when considering level of risk. 

(23)     Mr Rogers replied to a question from Mr Howard Rogers on extremely high temperatures by saying that in addition to the normal forecasting, there was also a Heat Health Watch Service, which was a Public Health / NHS product run by the Met Office.  It issued alerts when the temperature was due to reach 30+ degrees.   Similar modelling and graphs were produced for temperatures as for rainfall.  These indicated that temperatures were likely to rise to the point where monthly temperature records were set ever more frequently. 

(24)     RESOLVED that:-

(a)          Mr Mark Rogers be thanked for his valuable presentation;

(b)          Mr Rogers be invited to give a further presentation to the Committee in 2019 once the revised UK Climate Projections have been published; and

(c)          the Committee’s concerns on drainage be referred to the Environment and Transport Cabinet Committee in the light of the expert advice received from the Met Office during Mr Rogers’ presentation.