Weather of Friday 5th September 1958

[A Face like Thunder]

My family was abroad at the time, but it seems the weather of 62 years ago was particularly dramatic and horrendous in the south east of England:

131mm of rain at Knockholt and 102mm at Eynsford, both in Kent, and most of it in two hours

Two tornadoes causing a great deal of damage in the Horsham/Gatwick district

The UK's largest authenticated hailstone, 10 cm across and weighing 141g, which fell at Horsham. 

(Great British Weather Disasters by Philip Eden)

'Hailstorm of the Century' - The Surrey Weather Book by Mark Davison and Ian Currie.

Does anyone have any recollections of this particularly dramatic weather event?

 

 

 

[A Face like Thunder]

I wonder what our Netweather storm chasers would have made of this one 64 years ago today, and would a yellow warning for thunderstorms have been issued?!

[Metwatch]

Trevor Harley writes:

There were some exceptionally severe thunderstorms following a hot spell at the start of the month. There were particularly notable storms on the 5th and 6th, including hailstones up to 10 cm, flooding, and tornadoes. There was a bright early morning on the 5th, with very high humidity. The temperature widely reached 26C in the south on the 5th, with 27.2C at Whitstable and Mildenhall; the humid air was however very unstable, with temperatures decreasing rapidly with height, enabling some prodigious thunderclouds to develop. There were two main thunderstorm tracts: from Isle of Wight at 3pm to Colchester at 9.30pm; and Brighton from 7 pm moving north. The two tracts merged around 8 pm, giving the most severe weather, where a light easterly breeze met a light northerly. There were some exceptional downpours: 63.5 mm of rain fell in 20 minutes at Sidcup on the 5th (equal to 191 mm per hour, the third highest rainfall rate of the twentieth century), and 131 mm in 2 hours at Knockholt (Kent), along with destructive, large hailstones and tornadoes. At Swanley (also Kent) 57 mm of rain fell in 20 minutes. 1690 flashes of lightning in one hour were recorded in one of these storms. A gust of wind of 85 mph was recorded at Gatwick with one of the accompanying tornadoes. The heaviest recorded hailstone in the UK was caught at Horsham (Sussex) during this storm: it weighed 191g (6.75 oz), with a diameter of approximately 70 mm. The ground was pitted to a depth of 50 mm. Needless to say there was substantial destruction of trees and property across a substantial area. This famous storm is known as the "Horsham hailstorm". There were more severe thunderstorms in the SE on the 6th, with tornadoes, giant hail, and flash-flooding. 130 mm of rain fell in one storm at Sevenoaks."

 

Looking at the reanalysis not too surprising to see the thunderstorms become as severe as they did, the pattern is one of the most conducive and a very warm airmass within the trough of the main low pressure out west.

Edited March 25 by Metwatch