Wind over Ireland

The wind at a particular location 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 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 7 m.p.h.
in parts of south Leinster to over 18 m.p.h. in the extreme north. On
average there are less than 2 days with gales each year at some inland
places like Kilkenny but more than 50 a year at northern coastal locations
such as Malin Head. Indeed 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.
Wind
Measurement
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).
Notable Storms

"The
night of the Big Wind" on the 6th-7th January 1839 probably
caused more widespread damage in Ireland than any storm in recent centuries.
Winds reached hurricane force and between a fifth and a quarter of all
houses in Dublin experiened some damage, ranging from broken windows
to complete destruction. In more recent times, the year 1974 began with
a very stormy period, with record speeds occurring at a number of locations
on the night of the 11th-12th of January. 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 124 m.p.h. was recorded at Kilkeel
in County Down, making it the highest sea-level wind speed recorded in
Ireland.
WIND DIRECTION (percentage frequency of wind direction)
Circled number=%CALM
BEAUFORT SCALE OF WIND FORCE
| |
Wind
Force |
|
Short
Description |
|
Specifications
for use on Land |
|
Wind
Speed at 10 metres above Level Ground |
| |
|
|
|
|
|
|
Knots |
Metres
per second |
KM
per hour |
| |
|
|
|
|
|
|
|
|
|
| |
0 |
|
Calm |
|
Smoke
rises vertically |
|
<1 |
<0.3 |
<1 |
| |
1 |
|
Light
Air |
|
Direction
of wind shown by smoke but not by wind vanes |
|
1-3 |
0.3-1.5 |
1-5 |
| |
2 |
|
Light
breeze |
|
Wind
felt on face, leaves rustle, ordinary vanes moved by wind |
|
4-6 |
1.6-3.3 |
6-11 |
| |
3 |
|
Gentle
breeze |
|
Leaves
and small twigs in constant motion, wind extends light
flag |
|
7-10 |
3.4-5.4 |
12-19 |
| |
4 |
|
Moderate
breeze |
|
Raises
dust and loose paper, small branches are moved |
|
11-16 |
5.5-7.9 |
20-28 |
| |
5 |
|
Fresh
breeze |
|
Small
trees in leaf begin to sway, crested wavelets form on
inland waters |
|
17-21 |
8.0-10.7 |
29-38 |
| |
6 |
|
Strong
breeze |
|
Large
branches in motion, whistling heard in telegraph wires;
umbellas used with difficulty |
|
22-27 |
10.8-13.8 |
39-49 |
| |
7 |
|
Near
gale |
|
Whole
trees in motion, inconvenience walking against the
wind |
|
28-33 |
13.9-17.1 |
50-61 |
| |
8 |
|
Gale |
|
Breaks
twigs off trees, generally impedes progress |
|
34-40 |
17.2-20.7 |
62-74 |
| |
9 |
|
Strong
gale |
|
Slight
structural damage occurs (chimney pots and slates removed) |
|
41-47 |
20.8-24.4 |
75-88 |
| |
10 |
|
Storm |
|
Seldom
experienced inland, trees uprooted, considerable structural
damage occurs |
|
48-55 |
24.5-28.4 |
89-102 |
| |
11 |
|
Violent
storm |
|
Very
rarely experienced, accompanied by widespread damage |
|
56-63 |
28.5-32.6 |
103-117 |
| |
12 |
|
Hurricane |
|
- |
|
64
and over |
32.7
and over |
117
and over |
|