The Met Office issued a yellow thunderstorm UK warning at 5.24pm on Monday, June 22, covering parts of the South West until 9pm. Lightning had already been seen in Bristol that evening, and the warning stayed live as the storms moved through the region.
The alert covered Bath and North East Somerset, Bristol, Gloucestershire, North Somerset, Somerset, South Gloucestershire, Swindon and Wiltshire, with the same yellow warning also in place for parts of East of England, London and South East England. People in those areas were told to expect frequent lightning, heavy rain and gusty winds.
South West warning areas
TORRO said thunderstorms were developing in Devon and Somerset and moving ENE broadly, then expected to affect parts of Wales, as well as Wiltshire and Gloucestershire, over the coming hours. It warned of large hail, strong wind gusts and a small risk of a tornado as the stormy weather hit the region.
TORRO in the same statement said, "Thunderstorms are developing in Devon and Somerset, moving ENE broadly, and are expected to affect parts of Wales, as well as Wiltshire and Gloucestershire, over the coming hours. Associated risks of large hail, strong wind gusts and a small risk of a tornado with these."
Met Office impacts
The Met Office said an area of thunderstorms moving east across the area would bring a spell of frequent lightning, gusty winds, torrential rain, and hail in a few places. It said driving conditions could be affected by spray, standing water and hail, which could lengthen journey times, and it also warned of possible delays to train services and short-term power loss.
In its statement, the Met Office said, "An area of thunderstorms moving east across the area will bring a spell of frequent lightning, gusty winds, torrential rain, and a few places, hail." It added, "The majority of impacts are likely to come from other hazards however, such as lightning striking buildings and causing power cuts, difficult driving conditions in heavy rain, and some localised damage to vulnerable structures by strong wind gusts or hail."
20-25 mm rainfall
The Met Office also said the storms would be moving quickly, which would limit widespread heavy rain, but a few places could still see 20-25 mm in a short period during the most active storms. That leaves brief flooding as the sharper risk inside a wider warning built around lightning, hail and wind rather than a long rain band.
The Met Office said, "The storms will be moving quickly reducing the potential for widespread large amounts of rain, but there is a few places could see 20-25 mm of rainfall in a short period in the most active storms, which could bring some brief flooding." By 9pm, the warning was due to end, and the immediate concern for affected readers was the fast-moving evening line of storms rather than any later update.
