The South Wales, Shropshire And Cheshire Tornado

[Coast]

On the 27th October 1913, a severe thunderstorm produced one or more tornadoes with touchdowns reported in South Wales, Shropshire and Cheshire - one being a killer whirlwind with an 18 km path of devastation along the valley of the Taff in South Wales.

The South Wales event was a moderately devastating tornado (T6 on the TORRO scale) which means that the winds were, at its worse, in excess of 160 mph. The track of this tornado was 11 miles (17.7 km). Three people were killed (the worst confirmed death-toll for a recent UK tornado), scores injured and damage to property was estimated at £40,000 in terms of repairs required - a considerable sum equivalent to around £2.5 million today. Add on the sorts of things people claim for with insurance these days and that damage figure would likely be tenfold or more in modern terms.

Abercynon

First reports of the storm were in the Exeter area at around 1600, indicated the severity of the thunderstorm: for instance, a meteorological observer at Cullompton, Murray T. Foster, recorded:

"The day had been more or less overcast and the temperature high for the end of October, with a falling barometer. At about 3.45 p.m. heavier clouds came up from the South-west, with freshening wind and rain, until at 4 o'clock there were several flashes of lightning and thunder . . . Then at 4.05 p.m. a perfect deluge of rain fell, followed at once by a terrific hailstorm such as the oldest inhabitant never remembered having seen . . . This storm lasted over 10 minutes. A noticeable fact was that the temperature was hardly affected either on the grass or in the air."

Retired Indian Civil Service member W. A. Willock commented thus:

"I left Exeter in my motor-car on my way back to Ottery St. Mary at about 3.45 p.m. The day had been fairly fine, with a few light passing showers, in spite of a South-east wind and a low and falling barometer. It was beginning to rain a little when I started... About 3 miles from Exeter I saw a very black cloud, from which rain was falling heavily, coming up apparently from the South-east. I may have been deceived as to the direction of motion, however, owing to the motion of the car. In a couple of minutes we plunged into it, and I do not think I ever saw such rain out of the tropics. The lightning was very vivid and close, but the flashes were not more frequent than in a fairly bad thunderstorm . . . Immediately after the storm passed I could see it in the shape of a dense bluish cloud about 10 miles off to the North-west. . . The cloud only covered a very small breadth, and it had not given any rain to speak of between the place where we stopped, about 5 miles from Exeter, and Ottery."

The storm continued to move north into Somerset and crossed the Bristol Channel coast at Watchet, to make landfall on the Glamorgan side at about 1740. The tornado appears to have developed somewhere close to Efail Isaf and Llantwit Fardre, villages situated just east of Llantrisant and just north of the M4. In this area, its track was "fifty yards wide" and winds were strong enough to do considerable damage to light outdoor structures such as hen houses and hayricks. Continuing in a straight line, almost due north as seen in the map below, it had widened its track to "two hundred yards at Cilfynydd and over three hundred yards at Edwardsville".

The demarcation line between the tornado's path and the areas on either side was highly pronounced with no wind damage outside of the path. The tornado was accompanied by intense lightning and torrential rain as it reached its peak at Abercynon and Edwardsville.

Meteorological observers were few and far between in South Wales in 1913, but a Fellow of the Royal Meteorological Society lived at Edwardsville, Mr. B. P. Evans, who was headmaster at the local senior boys' school. His account of the incident is of classic status in UK tornado reporting:

"At 4.30 p.m. the wind, a gentle breeze, was from S. by E and by 5 p.m. was due S. At 5.15 p.m. a dead calm set in. The sky from 430p.m. was heavily mottled with dark patches of cumuli in the South, but these clouds presented straight edges in the SSE. It was a "troubled" sky.

To the South, as the twilight advanced, a dark sullen sky was noted. The cumulus form had disappeared except in the East, where a heavy mottled appearance was still observable until darkness came swiftly. During about half-an-hour of calm the atmosphere was oppressive, giving one a sense of great uneasiness, and a remark was made that rain would probably ease the tenseness.

Rain began to fall at 5.20 p.m. The first flash of lightning (red) was noted at 5.25 p.m., coming from a dark cloud bank in the South The rain ceased in about 10 minutes, and the red-coloured was followed by intensely blue lightning, flashing at frequent intervals. Very few peals of thunder were heard, these being sharp, with an absence of reverberation, and from about 5 40 p m the thunder was not evident. The blue lightning was appalling. When the flash occurred, which was most frequent, there seemed to be three or four interweaving flashes, all of a deep blue, and, what was strange, the waves of blue fire seemed to be rolling on the ground.

A few seconds before 5.50 p.m. we heard a noise resembling the hissing of an express locomotive. The sound grew rapidly in volume, at last resembling the rushing speed of many road lorries racing along. The oppressiveness that had been previously noticed increased, and the heat and air-pressure were pronounced during the rushing noise.

We endeavoured to move out of the room to the passage for greater safety, because a hurried remark was made that the engines of these supposed passing loaded steam lorries had collided before the house, and were about to burst, when the panes of our windows were broken by stones, tiles, slates, dried cement, and splintered timber. The missiles broke the Venetian blinds and struck the opposite walls. We made for the rear of the house, but all the windows were being bombarded also by small material and corrugated iron sheets.

We could distinctly hear the chimney-pots fall on the roof, and the material sliding off being dashed on the pavement and doorstep. We could see the kitchen clock from the hall passage. It had stopped at 5.51 p.m. It was not struck by any object. It is the largest clock in the house. Two smaller clocks in other rooms were not affected.

After this crash had ceased (this only lasted from 60 to 90 seconds), rain fell in torrents. The lightning set fire to the tar which had been sprayed some three weeks previously on the main Cardiff and Merthyr road, some 12 yards from our house door. A distinct smell of sulphur pervaded the air. The lightning continued fitfully and much less intense for about 5 minutes after the climax of the storm had passed, and thunder occurred during the rushing, crashing, roaring noise."

www.geologywales.co.uk

Photos courtesy Andrew Quick and www.alangeorge.co.uk

[Weather-history]

Here's the thread I posted on this, a couple of years ago with Times articles on the event

http://www.netweather.tv/forum/topic/41129-thunderstormstornado-october-1913/