London storms of 13th June 2006
Early storms in summer are not too uncommon however the localised ferocity of the storms that
affected East London on the 13th June was notable. The storms developed as a very warm southerly flow covered the UK
giving a period of protracted early summer warmth from the 3rd June. The day before (12th) had been very hot for early June with 31.4°C recorded at Heathrow and 31.3°C at
Northolt. In central London itself as high as 32.4°C was recorded in Clerkenwell. This
represented the hottest 'June 12th' ever recorded.
Synoptic situation at 00Z 13th June 2006
By early on the 13th a plume of very warm air lay across
the south east with a cold front lying from the Isle of Wight to the Wash. To its south east lay the very warm air as
much cooler air slowly over-rode it from the NW. Although there was some cloud cover initially from earlier overnight storms
between about 5am and 9am (which themselves gave localised rainfalls of about 8mm in an hour) temperatures
rose slowly and reached 27C at Hastings. However although temperatures were not especially
high further north the trigger temperature needed to initiate convection was not especially high and the air became unstable
as it was heated during the day and was helped by a convergence zone that formed as sea breezes developed to the east and
south of London which initiated the convection. As cooler air was also overiding the warmer air at upper levels
this also helped in the development of the severe storms.
Particularly badly affected was the area around Woodford Green in London. As the early storms moved away
by mid morning the sun was able to readily heat the air and temperaures reached 26 degrees C in central London by
mid afternoon.
The high temperatures helped further storms develop during on convergence zones by the mid afternoon and move
up into SE London. They gave localised heavy rain in a number of areas as they moved into Essex with several
places seeing local flash flooding with subsequent damage to properties and the fire brigade in attendance
to pump out basements.
Further thunderstorms returned to the area in the late evening with the area around Woodford Green seeing
another period of heavy rain; almost 10mm falling in the space of an hour.
By the 14th cooler fresher weather had worked into the area with temperature only reaching 18C at
best.
