One year on – Storm Gareth causes widespread flooding across the United Kingdom

On the 12 and 13 March 2019 Storm Gareth brought strong winds and heavy rain to western Ireland, northern England, Wales and Scotland. Falling on already saturated ground, the persistent wet weather resulted in widespread flooding from rivers on 16 and 17 March 2019. Some of the worst affected areas were in north Wales, Lancashire, Cumbria and Yorkshire.

What happened during Storm Gareth?

Storm Gareth was an intense area of low-pressure named by Met Éireann, which passed over the UK on 12 and 13 March 2019. It was the latest in a conveyor-belt of storms to pass over the UK during February and March of that year, caused by a more southerly and stronger positioning of the Atlantic jet stream, which acts as a steer to low pressure systems. The strongest winds were forecast for Northern Ireland and northern coasts, although much of the northern UK was expected to experience severe gales with a Met Office Yellow Weather Warning for wind in place on 12 and 13 March, followed by Weather Warnings issued on 15 and 16 March for wind, rain and snow.

16 March 2019 Ilkley_Monitoring

On Saturday 16 March, persistent heavy rain fell on already saturated catchments, causing river levels to rise and burst their banks in northern England and Wales. Some of the worst affected areas were along the rivers Ouse, Swale, Calder, Ure, Severn, Wharfe, Vyrnwy, Nidd, Eden, Aire and Mersey.

In just 24 hours, Capel Curig in Caernarfonshire recorded more than half a month’s worth of rainfall with a total of 136.6mm (BBC, 2019a).  Flooding across parts of the rail network impacted rail services in the North West and Yorkshire. (BBC, 2019b).

Flood Foresight and Storm Gareth

Storm Gareth_case study

Our Flood Foresight system monitored and analysed Storm Gareth across all three of its Rainfall Screening, Flood Forecasting and Flood Monitoring modules. Flood Foresight monitored river flooding events driven by live telemetered river gauges with three hourly updates throughout the duration of Storm Gareth. Its Flood Monitoring module generated flood depth and extent maps which indicated that Lancashire was the area most affected by fluvial flooding, followed by Yorkshire and North Wales.

Click on the image to the right to read the full Storm Gareth case study.

River Conwy flooding during Storm Gareth

Flood Foresight first forecast flooding for the River Conwy in North Wales on 15, 16 and 17 March at lead times of eight days, nine days and five days respectively. Consecutive daily forecasts for flooding on 16 March started at the four-day lead time, and five-day lead time for 17 March. The real-time Flood Monitoring footprint showed flooding on 16 March between 09:00 and 21:00 UTC.  The peak flood extent began to recede in North Wales during the late afternoon of the 16 March, and in north west England in the morning of the 17 March.

16 March 2019_Llanrwst_Forecasting
16 March 2019: Flood Foresight flood inundation monitoring, River Conwy, Llanrwst

Want to know more?

Flood Foresight is a globally-scalable operational system providing data on rainfall severity, flood inundation footprints and depth, and flood impacts. Flood Foresight supports operational flood management in the infrastructure, insurance, utilities and civil contingencies sectors, and is designed to be compatible with existing business intelligence and decision support tools. Find out more about our flood forecasting and real time flood monitoring system at www.floodforesight.com. You can also email John Bevington.

References

BBC (2019a) Flood warnings remain across UK following downpours, accessed 19 March 2019.

BBC (2019b) Rail services and roads hit by flooding, accessed 19 March 2019.



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