Was 2019 a sign of how climate change is affecting weather patterns?
Featured image: Environment Agency
January was a relatively calm and dry month, with only 45% of average rainfall. The East and North East of England had the its second driest January (based on records dating back to 1910). Strong winds in Scotland in the first half of January caused some disruption, including school closures. Towards the end of January, snow fell in parts of the country, also causing some disruption to schools and travel.
February saw record breaking temperatures and sunlight, the mean temperature was provisionally 2.3°C above the 1981 – 2010 long-term average. It was the second warmest summer on record since 1910 and a new maximum temperature record of 21.2°C was recorded at Kew Gardens. Sunshine in February was 163% of the average amount, making it the sunniest February based on records from 1929, just ahead of February 2008. March and April were also a degree or more, warmer than average.
March saw the arrival of Storms Freya and Gareth. Storm Freya caused winds of up to 76mph in some, as well as some coastal flooding. In addition, snow fell across the northern Pennines, which caused travel disruption between Northumberland and Cumbria. Strong winds from Storm Gareth affected the UK on the 12th and 13th March causing travel disruptions, localised coastal flooding from wave overtopping and flooding in Cumbria due to heavy rain.
The month of July brought contrasting weather which showed how much the weather can change in such a short space of time. On the 25th July, a new UK temperature record of 38.7°C was recorded at Cambridge Botanical Garden as a result of a heatwave across the UK. However, in the very same week, flash flooding affected parts of Cheshire and North Yorkshire causing widespread damage to roads, bridges, homes, businesses and many people needing to be evacuated. In the second half of the year, above average rainfall caused several floods in July, September, October and November.
In Whaley Bridge, Derbyshire, the spillway of the Toddbrook Reservoir dam became damaged as a result of prolonged rain at the end of July and into early August. Large volumes of water were able to pass through the protective concrete facing, endangering the life of thousands of people. Whaley Bridge was evacuated and engineers began pumping water out of the reservoir which holds 1.3 million tonnes of water. The RAF dropped 530 tonnes of aggregate to plug the hole in the spillway and then concrete was poured in to seal the gap and cement the aggregate in place. Repair works are expected to take years and the reservoir will remain drained until they are completed, meaning the reservoir is likely to be out of use until 2022 or 2023.
The total rainfall for September was 151% of the long-term average (1961-90), with the highest rainfall totals in parts of Lancashire, Cumbria and Devon. For north-west England, it was the 8th wettest September on record (records from 1891) with April to September being the 3rd wettest on record.
In October, there was prolonged and persistent rainfall in many regions across the UK, which saturated soils, leaving many areas at an increased risk of flooding. This was caused by the jet stream which was situated further south than usual. The already saturated soils contributed to the exceptionally high river flows in central and northern England in November, with catchments in South Yorkshire, Derbyshire and Nottinghamshire recording their highest ever peak flows. During the month of November, a slow-moving occluded front (where a cold weather front overtakes a warm front and the warm front is lifted from the surface) brought heavy rainfall across parts of Lincolnshire, Derbyshire, Nottinghamshire and South Yorkshire. Around 50 – 100mm of rainfall fell in 24 hours from the Humber to Sheffield, which was the average rainfall for the whole month. As the catchments were already saturated from heavy rainfall in October, the persistent rain caused severe flooding from the River Derwent in Derbyshire and the River Don in South Yorkshire. Many homes were flooded and hundreds of residents had to be evacuated. New daily and peak flow records were established on the River Don and River Derwent in Derbyshire which exceeded the flows recorded during the floods that took place in the area in 2007.
Unusually, the first storm of the 2019/2020 storm season was announced on the 6th December 2019 (Storm Aityah), this is late in comparison to the 2019/19 storm season where two occurred in September and one in October. December was also milder than usual, with the UK provisional mean temperature around 1.3°C higher than average.
The various weather events that took place in 2019 just show how changeable and unpredictable the weather can be. From unseasonably high winter temperatures in February, to numerous flooding events in the second half of the year, is this a sign of things to come and an indicator of how climate change will affect us in the future?
Sources: Met Office, BBC, Centre for Ecology and Hydrology, Brunel University London, The Guardian, The Environment Agency