What’s in a name?

In September 2015, the UK Met Office and Met Éireann (the Irish meteorological service) announced a project to give names to potentially damaging storms. The basis for naming any particular storm was the expectation that there would be major impacts on conditions over the British Isles and, in particular, of very high winds. But the very first winter that this scheme was applied, the winter of 2015/2016, not only did some of the named storms bring high winds, but they also caused exceptionally heavy rain and consequent devastating floods.

The first storm, Abigail, brought high winds to northern Scotland and the Outer Hebrides, and heavy rain farther south in Cumbria. The next, Barney, was accompanied by high winds (particularly over Ireland) and more heavy rain, as was the third storm, Clodagh, when there was a gust of 84 knots (156 kph or 97 mph) at High Bradfield in South Yorkshire.

But it was Storm Desmond that brought real trouble on 4—6 December. It had moderately high winds, but dumped a vast quantity of rain, most of it on Cumbria. Honister Pass experienced the new British rainfall record for 24 hours, with 341.1 mm between 18:00 GMT on 4 December and the same time on 5 December. Nearby Thirlmere set a new British rainfall record of 405 mm for the 48 hours to 09:00 GMT on 6 December.

Part of the trouble was caused by the fact that November 2015 had been the second wettest recorded since 1910 (only 2009 was wetter). The ground was already waterlogged before Desmond arrived. The resulting flooding was widespread, especially in Cumbria, where the West Coast Main Line to Scotland was cut. Lancashire, Northumberland, (with flooding on the River Tyne) and southern Scotland were also badly affected. Tens of thousands of homes were flooded in numerous towns and villages, and particularly in Carlisle, where the River Eden overflowed. The heavy rainfall also caused major problems and flooding in both Northern Ireland and the Irish Republic.

But then Storm Eva arrived, with high winds on 23 and 24 December, but brought still more heavy rain on 25 and 26 December. This time the worst flooding was farther south, in Lancashire, northern Manchester, and across the Pennines to West Yorkshire. The torrential rain on Boxing Day caused major flooding as the water moved downstream, such as at Hebden Bridge in Yorkshire and York itself. Thousands of more homes and businesses were flooded and at least 20,000 were without power. This single storm brought about three-quarters of the rainfall normally expected for the whole of December. Falling on saturated ground, and with rivers already in full spate, widespread flooding was inevitable.

Storm Frank arrived at the end of December and this time particularly affected southern Scotland, with thousands more homes flooded, including in Dumfries. Farther south, a band of heavy rain produced severe flooding in southern and south-eastern Ireland.

There was a succession of lesser depressions with winds and rain in the New Year, but on 29 January, Storm Gertrude arrived. This tracked much farther north, mainly affecting northern Scotland with exceptionally high winds. The highest gust of the winter, 91 knots (169 kph or 105 mph) was recorded at Baltasound in Shetland.

At the beginning of February, Storm Henry brought strong winds to most of Scotland, which was followed by Storm Imogen on 7 February. That took a more southerly track and produced heavy rain and high winds over southern England (a gust of 81 knots = 150 kph or 93 mph at the Needles on the Isle of Wight), with gigantic swell waves affecting south-west England. The lowest pressure (962 hPa) of the winter was recorded at Lerwick in Shetland on 7 February.

That was the winter of 2015/2016. Of course, terrible weather and floods occurred before storms were named. In the winter of 2009, there was extreme rainfall in Cumbria. Then part of Workington being isolated when a bridge collapsed, with the death of a policeman who was trying to divert traffic away from the danger. There was more than two metres of water in parts of Cockermouth. The British rainfall record for 24 hours was set between midnight 9 November and midnight 10 November, when 316 mm of rain fell on Seathwaite in Borrowdale. That record was to be broken in December 2015, when Storm Desmond brought 341.1 mm of rain to Honister Pass. The rainfall in 2009 appears to have resulted from a phenomenon, recently given a specific name: an ‘atmospheric river’, which turns into what is known as the ‘warm conveyor belt’ within a depression system.

Featured image credit: Waves by NeuPaddy. Public Domain via Pixabay.