Introduction
On 23 June 2004, there were very strong winds over parts of
England, Wales and Northern Ireland. Damage was caused to houses
and transport and electricity supplies were disrupted. It was
quite unusual to have such strong winds in the summer part
of the year. Some parts of England had the strongest winds
ever recorded in June, of 60 miles per hour.
Heavy rain also occurred which led to flooding and caused and
caused interruptions to the tennis at The Wimbledon Championships.
 |
 |
| Fig 1: Fallen tree on car |
Fig 2: High waves |
Areas affected
| Fig
3: Affected areas |
 |
Physical impacts
Fallen trees
A number of trees were blown down or branches snapped off by
the strong winds. This problem was made worse because the winds
occurred during the summer, when the trees were still full of
leaves. Strong winds normally occur in winter when there are
no leaves, so the wind can blow straight through the branches.
When the trees are fully leaved in summer, it is harder for the
wind to blow through and this helps to push over the tree.
Damaged roofs
Roofs, fences and walls were damaged over parts of England,
Wales and Northern Ireland. One girl received leg injuries as
a result of being hit by roof tiles from the Youth Centre in
Swansea.
 |
 |
| Fig 4: Fallen tree |
Fig 5: Wind damage to roof |
Brighton Pier damaged
Brighton's West Pier, which opened in 1866, was badly damaged
in the strong winds and high seas. No one was injured as it has
been closed to people since 1975.
High waves
The strong winds caused high seas along coastal areas.
 |
Fig 6 (left): Brighton’s
West Pier is damaged in the strong winds
Fig 7 (below): High waves |
Human impacts
Transport
Ferries were cancelled across the Irish sea and across
the English Channel between Dover and Calais in France.
The older River Severn Bridge in Wales was closed to traffic
because of the strong winds.
Train services were cancelled and delayed as trees fell
onto the railway tracks. Leaves blown onto the track affected
the speed that the trains could travel along them.
Motoring accidents occured on roads and motorways when
branches from trees and other debris were blown onto them.
Cruise ships were not able to arrive into ports and had
to wait until the winds died down. |
 |
Fig 8: Spray over train lines |
Power supplies and phone lines interrupted
Fallen trees damaged electricity and phone lines and caused
power cuts and interrupted phone lines for peoples’ homes in
south and south-eastern England.
8,000 homes in Northern Ireland were left without electricity,
including Ballykelly.
Outdoor events affected
The Glastonbury music festival was affected. Strong
winds meant that people found it difficult to put their
tents up and the festival ground became flooded and muddy
due to the rain.
175 tennis matches at Wimbledon were cancelled around
23 June 2004.
Spectators at Wimbledon bought 1,000 umbrellas and 2,500
rain ponchos. The organisers had to refund £1 million pounds
to 25,000 people who had bought tickets in advance.
 |
| Fig 10: Rain disrupts play at
Wimbledon |
|
|
Fig 9: Glastonbury |
Theory
Weather map
Figure 11 shows a weather map for midday on 23 June
2004. It shows a large area of low pressure, known as
a depression, over the UK.
The solid lines are called isobars, which are lines drawn
on a weather map to join places which have the same atmospheric
pressure. Where the isobars are closest together, the wind
is the strongest.
There is also a weather front wrapped around the centre
of the low which brings lots of cloud and rain.
It is unusual to see such a deep area of low pressure
area over the UK in summer.
|
|
Fig 11: Weather chart for midday (12 p.m.)
on 23 June 2004 |
Satellite imagery
Fig 12 shows a visible satellite image for the UK and
Europe at 11 a.m. on 23 June 2004. Visible satellite
pictures show what you would see if you were in space
looking down on the Earth.
White areas show where there is cloud, the brighter the
shading the thicker the cloud.
There is lots of thick cloud wrapped around the area of
low pressure shown in the weather chart. The cloud indicates
a weather front which caused lots of heavy rain over the
country.
Fig 12 (right): A visible
satellite image for 11 a.m. on 23 June 2004 |
|
 |
Maximum wind speeds
Fig 13 (far right) shows the peak wind speeds recorded
on 23 June 2004. The wind speeds are given in knots.
A knot is a measure of wind speed
and is equal to about one mile per hour (one knot
= 1.15 miles per hour or 0.51 metres per second).
For example:
30 knots = 35 m.p.h.
50 knots = 57 m.p.h.
70 knots = 81 m.p.h.
Wind speeds are observed with an instrument called
an anemometer (right). |
|
 |
|
|
Fig 13: Peak winds in knots on 23 June
2004
|
Rainfall and radar
As well as strong winds there was also
lot of rainfall with the area of low pressure. The rainfall
meant that no play was possible at the Wimbledon tennis
championships on that day.
Figures 16 to 23 show a sequence of radar pictures from
9 a.m. to 4 p.m. on 23 June. Alternatively figure 15
shows an animation of the same images. The ‘Rainfall
rate’ key shows how the colours in the image relate to
the rate at which rainfall is falling. For example the
orange areas indicate that rain is falling in there at
4 mm per hour.
Rainfall radar can be used to show where the rain is falling,
where it fell and how heavy it was.
Fig 15 (right): Animation
of radar pictures between
9 a.m. and 4 p.m. on 23 June 2004 |
 |
 |
 |
 |
Fig 16: Radar image for 9
a.m. on
23 June 2004
|
Fig 17: Radar image for 10
a.m. on
23 June 2004
|
Fig 18: Radar image for 11 a.m. on
23 June 2004
|
 |
 |
 |
Fig 19: Radar image for 12 p.m. on
23 June 2004
|
Fig 20: Radar image for 1 p.m. on
23 June 2004
|
Fig 21: Radar image for 2 p.m. on
23 June 2004
|
 |
 |
|
Fig 22: Radar image for 3 p.m. on
23 June 2004 |
Fig 23: Radar image for 4 p.m. on
23 June 2004 |
|
Responses - discussion
- Electricity and telephone engineers worked to restore services
to homes which had been cut off
- Councils removed trees and debris from roads and motorways
- People were stopped from going on Brighton beach until parts
of the collapsed pier were removed
- Ferry services were cancelled between Holyhead and Dublin
and also cross channel ferries
- Organisers at the Wimbledon tennis tournament had to pay
out £1m in refunds to visitors
|
