Subsidence View - August 2017
The current Subsidence Surge Risk is now assessed as "Mid Amber". Despite the wetter than average July, the MORECS measure of Soil Moisture Deficit remains at a similar level to the significant surge year of 2003 and based on the forward weather forecast a full blown subsidence event year cannot yet be discounted. The deciding factor for claim volumes will be what actually happens next - another heatwave, normal summer weather or a prolonged period of rain?
After a good deal of fine weather in June a transition to more unsettled weather took place during July. Early in the month temperatures peaked at over 30C (86F) in the south, but the second half of the month saw cooler Atlantic air becoming dominant.This resulted in above average rainfall in the clay soil areas of south east England, although more than 50% fell in just 1 day during 11th July.
As a result the MORECS measure of Soil Moisture Deficit remained steady and is now at the same level as the significant surge years of 2003.This month we have also included historic figures for 2009, which was a year when the maximum MORECS was not reached, but claim numbers still peaked in September/October at more than twice the previous monthly average.
So what does August have in store in terms of weather?
The Weather Outlook (TWO) summer forecast has now been updated and notes the following:
The TWO monthly headline is for August to be quite a mixed month with temperatures close to average in the north and slightly above in the south. Rainfall levels are forecast to be close to average. Overall confidence is quite low because some of the medium range computer models are suggesting the possibility of a return to more settled weather. The TWO view is that on balance an Atlantic based pattern is more likely to win out than a blocked high pressure scenario, and that suggests quite a changeable outlook. Nonetheless small adjustments to the set-up of the pressure blocks across the North Atlantic region could lead to a much more settled and warmer month.
The latest Met Office 30 day forecast notes the following:
UK Outlook for Monday 7 Aug 2017 to Wednesday 16 Aug 2017: It will be an unsettled start to next week with rain followed by showers moving eastwards across the UK... from midweek onwards high pressure is likely to be dominant across the south bringing some drier and sunnier conditions here...after a cool start to the week, temperatures are likely to recover to near average, and perhaps turning warm across the southeast. Towards the middle of the month the north-south split is likely to continue, with the north continuing to remain changeable, with the south seeing the best of the drier weather.
UK Outlook for Thursday 17 Aug 2017 to Thursday 31 Aug 2017: The second half of August, sees the confidence in the forecast reduce significantly, but a northwest-southeast split is most probable. This would result in the northwest seeing the most frequent wet weather, and the southeast seeing the best of the drier and brighter interludes. Temperatures are likely to be around average, although southern areas may turn warm at times.
In view of the elevated MORECS and the uncertainty of the forecasts, BVS consider that the underlying subsidence surge risk remains. The deciding factor for claim volumes will be what actually happens next - another heatwave, normal summer weather or a prolonged period of rain? Accordingly, the surge risk is currently assessed as "Medium Amber". Our prediction for 2017 is for ABI claim numbers to be higher than the previous 3 year average of 17,000 and a full blown surge still cannot be ruled out.
If you would like to talk to us about how Building Validation Solutions can help with your subsidence surge plan or improve you approach to subsidence claims generally, please contact Giles Carter on firstname.lastname@example.org