Thunderstorms and heavy rain on 13 to 15 June 2009

15 June 2009

Background

A series of slow-moving, thundery showers affected many parts of the UK over the weekend and into Monday. Heavy rain and hail caused localised flooding in many parts with lightning strikes also causing problems.

On Monday, showers developed rapidly across southern Scotland during the morning and then widely across many areas of England and Wales during the afternoon and evening. Over northern, eastern and south-west England the showers became very heavy, with some developing into intense thunderstorms. Lines of shower development are shown on the 1300 analysis chart. Some of these thunderstorms were slow moving with hail, and brought torrential downpours. Very high hourly totals were recorded locally, with Heacham in Norfolk capturing two very intense storms. At 1400 — 20.2 mm was recorded at the Heacham rain-gauge, with a further 23 mm in an hour then recorded at 1600. There were also various reports of funnel clouds during the day, including one in Cambridgeshire and another in Lancashire.

Analysis chart valid 1300 Monday 15 June 2009.

Into the evening, the heaviest showers were situated along the spine of England and into East Anglia towards the eastern side of London, captured by the satellite and radar images for 1800. At around this time a thunderstorm developed over central London, with reports of lightning strikes and hailstones. A torrential downpour in Bocking, Essex dropped 23.8 mm in an hour. The thunderstorms and showers slowly cleared away to the east during the night.

High-resolution visible satellite image 1800 Monday 15 June 2009.

Radar 1800 Monday 15 June 2009

Impacts

Around 12,000 homes and business in Northern Ireland were left without electricity over the weekend after lightning strikes caused over 70 faults (BBC News). Rural parts around Coleraine, Ballymena, Larne, Craigavon and Dungannon were worst affected.

In Scotland, landslips affected roads in Dunbartonshire and Argyll & Bute on Sunday and Monday. Lightning killed 16 bullocks at a farm in East Lothian on Sunday (BBC News).

Monday also saw traffic disruption with road and rail networks affected by localised flooding. Dunblane High School was closed on Monday due to flash flooding  (BBC News).

Localised flooding and lightning were reported across many parts of England on Monday 15 June:

• Flooding in Durham (BBC News)
• Lightning strike in Sheffield (BBC News)
• Lightning flooding West Yorkshire (Yorkshire Post)
• South Yorkshire floods/lightning (the Star)
• Flash flooding brings misery (Western Morning News)

Devon & Cornwall:

• Flash floods hit homes and roads (BBC News)

North-west:

• Flash floods lead to road closures (St Helens Star)
• Peter Street Community Centre closes after lightning strike (St Helens Star)

Flash flooding and lightning strikes caused travel disruption in East Anglia and Essex. Ipswich railway station was closed after a lightning strike damaged a chimney in the evening.

• Storms spark UK flash floods (the Independent)
• Region hit by heavy summer storm (BBC News)
• Thousands of homes left without power after storm (Evening Star)
• Some photos of lightning over London and hail in East Anglia (Daily Mail)

Weather data

Altnahinch in Northern Ireland reported 46.4 mm of rain on Saturday with 13.2 mm falling in one hour on Saturday afternoon and a further 31.2 mm on Sunday.

On Monday, areas as far apart as Leicestershire, Suffolk, Perthshire and Lanarkshire reported 12 or 13 mm of rain in an hour during either Sunday or Monday.

Monday 15 June

Hourly totals:

1200–1300	13.4 mm	Cottesmore, Rutland
1300–1400	20.2 mm	Scargill (EA gauge northeast)
1300–1400	20.2 mm	Heacham, Norfolk (EA gauge)
1300–1400	16 mm	Cranwell, Lincolnshire
1500–1600	23 mm	Heacham, Norfolk (EA gauge)
1800–1900	23.8 mm	Bocking, Essex (EA gauge)

Overall totals — up to 2200:

Heacham, Norfolk	48.2 mm
Charterhall, Scottish borders	25 mm
Drumalbin, South Lanarkshire	20.2 mm
Coleshill, Birmingham	20 mm
Cranwell, Lincolnshire	20 mm
Cottesmore, Leicestershire	18.4 mm

What we did

Met Office weather Advisory Warning for Monday was issued on Friday 12 June, highlighting the potential for very heavy thunderstorms over many parts of England and Wales. Flash warnings were also issued over the weekend and into Monday with updates to the Weather Advisory.  Met Office staff across the UK provided emergency responders with detailed information on the how the weather might affect them.

Please note that all values and statements are provisional and subject to change.