Past winter storms were more brutal

MANY people have been talking about exceptionally prolonged, windy weather this winter, which has caused a good deal of damage.

Yet again, the belief is that it’s all down to climate change.

What isn’t these days? However, we are undoubtedly getting more gales than previously; at the same time, records show that winters are getting milder, with far less snow and frost. But, two months of continuous high winds left thousands of people without a phone service for days in December and January. Some homes have had no phone service over the last two months. The Irish Farmers’ Association (IFA) is calling on the Government and ComReg to sort out this issue.

Pressure is on eircom to get faults repaired and the IFA is not happy with the rate of progress. An IFA spokesman said despite the best efforts of line repair staff across the country, they simply do not have the resources to deal effectively with the crisis.

A lot of trees have also been uprooted and pressure will inevitably come on landowners to cut down roadside trees, which have been loosened at their roots by the winds. The wind can be influenced by a number of factors such as obstruction by buildings or trees, the nature of the terrain and deflection by nearby mountains or hills. For example, the Met office points out that the rather low frequency of southerly winds at Dublin Airport is due to the sheltering effect of the mountains to the south. The prevailing wind direction is between south and west. Average annual wind speeds range from 7mph in parts of south Leinster to more than 18mph in the extreme north.

On average, there are less than two days with gales each year at some inland places, such as Kilkenny, but more than 50 a year at northern coastal locations such as Malin Head. The north and west coasts of Ireland are two of the windiest areas in Europe and have considerable potential for the generation of wind energy. But the winds of the current are but a zephyr when compared to some of the more notorious storms that history has recorded.

The night of the Big Wind, on January 6-7, 1839, for example, probably caused more widespread damage in Ireland than any storm in recent centuries. On that night, winds reached hurricane force and between a fifth and a quarter of all houses in Dublin were damaged.

In more recent times, 1974 began with a very stormy period, record speeds occurring at a number of locations on the night of January 11-12. Trees were blown down, many buildings were damaged and electricity supply to 150,000 homes was interrupted. It was during this storm that a gust of 124mph was recorded at Kilkeel, County Down, making it the highest sea-level wind speed recorded in Ireland.

In our preoccupation with the weather in everyday conversation, we talk about the wind — a lot of wind about wind, you might say. But how much do we know about the wind and how accurate are our descriptions? What are the differences, for instance, between gales, storms and hurricanes? Since the days of Admiral Sir Francis Beaufort (1774-1857), who introduced the Beaufort scale of wind force, the knot (one nautical mile per hour) has been used as a unit of wind speed. Modern meteorological practice, however, is to use metres per second (1 metre per second = 1.94 knots = 2.24 miles per hour).

The Beaufort scale of wind force runs from zero (calm) to 12 (hurricane), the highest point of the scale.

Defining the strength of the wind is not an exact science when we talk among ourselves about the weather, but there are some helpful definitions accompanying the Beaufort scale. Going by the scale, you know it’s calm when you can see smoke rising from chimneys, with scarcely a quiver. Light air is indicated by the wind direction is shown by smoke, while a light breeze is defined by a feeling of wind on your face and ruffled leaves. There’s a strong gale when slight structural damage occurs, including damage to chimney pots and slates being removed. In a storm, trees are uprooted and considerable structural damage occurs. A violent storm, which is rarely seen in Ireland, leaves a trail of widespread structural damage behind.