Twelth Night Tempest

Armagh Observatory, 1 January 1999

On Boxing Day last year we all felt the effects of storm force winds. Trees were uprooted and the roofs of some dwellings were lifted off. This reminds us of the night of another storm, the so-called Big Wind which occurred across the country exactly 160 years ago, on Twelfth Night, 6/7th January 1839.

Widespread havoc was reported throughout Ireland as a result of that hurricane. The cost in human terms was immense. According to Peter Carr in his book, "The Night of the Big Wind," over 200 people lost their lives in Ireland and its surrounding waters. He further comments that 'slated roofs were plucked clean like Christmas turkeys.' Newspapers reported that much livestock and food supplies were lost, and many tens of thousands of trees were destroyed.

Records at the Armagh Observatory, show that snow had fallen on Saturday 5th January 1839 and the atmospheric pressure was 29.23 inches of Mercury (990.0 millibars). A spot pressure reading on Sunday evening (6th) showed that the pressure had dipped to 28.28 inches (957.7 mb) and perhaps lower, while the temperature rose by some 9 degrees Celsius, resulting in the hurricane-force winds. The readings are annotated with the remark 'a tremendous gale in the night.'

The Big Wind may have inspired the then Director of Armagh Observatory, Revd. Romney Robinson to invent the world-famous Robinson Cup-anemometer. Developed in the 1840s, this wind-gauge was used by Dr Robinson and his successor, Dr Dreyer, to make a 55-year series of wind speed and direction measurements from 1852-1907.

For comparison, the weather statistics for Boxing Day 1998 were as follows. The pressure was 999 mb at 3.00 am on Saturday 26th December, while by 5.00 pm that day it had fallen to 964 mb. Also between 3.00 am and 1.00 pm, the temperature climbed quickly from about 1 to 11 degrees Celsius. Interestingly, this is a similar pressure drop and temperature rise to that of 6th January 1839.

FOR FURTHER INFORMATION CONTACT John McFarland, tel.: 01861-522928 (work), or tel.: 01762-879549 (home)

Last Revised: 15th June 1999
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