BRITISH WEATHER SERVICES –
METEOROLOGICAL REPORT:
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XXXX Solicitors
XXXXX
XXXXXXX
5 PAGES BY FAX: XXXXXXXX
XXXXXXXX -v- Ministry of Defence
Your reference: XXXXXXXXXXXX
Our reference: XXXXX
Date: 20th January 2005
Terms of Engagement:
I was instructed by XXXXXXXXX to investigate the meteorological factors surrounding the events
of 13th December 1998, concerning a XXXXXXX accident which occurred at XXXXXXX at
approximately 15.55 hours GMT. In addition to addressing the XXXXXXXX meteorological data
and various reports/statements concerned with this case, I was also instructed to make a site visit
to study the incident location and if practical take wind measurements on a day that had
reasonable similarities with the incident day.
Experience and Qualifications of the Author: I gained my meteorological observers qualification
in the Royal Navy in January 1982 and served on various ships and land based stations until
March 1985 – observing, plotting and providing meteorological data to aircrews and others.
I then served for 2 years as a meteorological consultant at Noble Denton, observing and plotting
the weather globally, with an element of forecasting. In December 1987 I formed my own firm,
British Weather Services and amongst a host of differing meteorological tasks, in total I have
provided expert witness reports, site investigations and evidence to courts/other concerns on
numerous occasions to-date.
The Meteorological Data supplied by the Met Office relating to 13th December 1998:
I have read the data supplied and have no reason to doubt its authenticity or in terms of the
historical data, its accuracy. The points I would particularly note are as follows and I will refer to
them in my conclusion -:
The Weathercall forecast issued at 1730 on Saturday 12th December for the XXXXXXX forecasts
a ‘bright and breezy day. A moderate or fresh 15-20 mph. westerly, becoming a moderate
southwesterly later’.
The Weathercall forecast issued at 0630 on Sunday 13th December for the XXXXXXXX forecasts
a ‘gusty westerly wind in the morning, with mean speeds around 18 mph gusts to 25mph, but the
wind should moderate early in the afternoon to around 15 mph. and will gradually back
southwesterly’.
BRITISH WEATHER SERVICES – METEOROLOGICAL REPORT:
Page 2 of 5.
XXXXXXXX v XXXXXXXXXX
* note: 1 knot = 1.15mph
The actual wind speeds from XXXXXXXX 96m AMSL-:
1500 GMT 190 deg. 11 knots sustained. Gust 17 knots from 190 deg (1548 hrs).
1600 GMT 190 deg. 11 knots sustained. Gust 19 knots from 190 deg (appx.1700 hrs).
1700 GMT 180 deg. 10 knots sustained. Gust 22 knots from 200 deg (1754 hrs).
The actual wind speeds from XXXXXXXX 96m AMSL-:
1500 GMT 190 deg. 9 knots sustained. Gust 16 knots from 200 deg (1536 hrs).
1600 GMT 210 deg. 12 knots sustained. Gust 22 knots from 210 deg (1642 hrs).
1700 GMT 200 deg. 11 knots sustained. Gust 20 knots from 200 deg (appx.1700 hrs).
The actual wind speeds from XXXXXXXX 107m AMSL-:
1500 GMT 180 deg. 6 knots sustained. Gust 13 knots from 200 deg (1506 hrs).
1600 GMT 180 deg. 7 knots sustained. Gust 13 knots from 180 deg (1612 hrs).
1700 GMT 180 deg. 8 knots sustained. Gust 16 knots from 160 deg (1706 hrs).
The Match Commentary:
I have been given extracts of the XXXX of the XXXXX - XXX v XXXXXX and noted the comments
made by the XXXXXX and will refer to them in my conclusion -:
“Cool windy day here at XXXXXXX”.
“What a windy day here”.
“The wind is behind XXXXX”.
“Carried on the wind”.
“…and on the wind it carried over the XXXX”. .
My Site Visit: I visited XXXXXXXX on Monday 17th January 2005. The reason for choosing this
day was that in the time from instruction to having to submit my report, this day had in my view
the greatest chance of having meteorological factors similar to that of the incident day - that is
from the days available to me.
The general conditions upon arrival at 1200 noon were overcast but relatively mild with a
noticeable wind broadly from the southwest. There was some light and intermittent drizzle in the
air, but it was essentially dry. Conditions remained similar throughout my visit.
I was met by XXXXXXXXXX and then the safety/ground staff of XXXXXX. I was advised by the
head of safety that due to the wet/slippery surfaces on the roofs, it would not be possible to go
onto the roofs that day.
Accompanied by XXXXXXX and an XXXXXX staff member, I entered the XXXXXX and began to
get an orientation of both the XXXXXXX and the incident location. I was advised at the outset
that the XXXXXXXXXXX had since been replaced by a larger stand.
I then was taken to the XXXX of the XXXXXX and climbed a ladder in order to be able to look out
onto the XXXXX. I faced into wind and although my position on the ladder coupled with
obstructing metal girders was not ideal in terms of exposure, I proceeded to take a wind speed
and direction readings between 1245 and 1300 GMT, using a Skywatch GEOS hand-held digital
anemometer.
BRITISH WEATHER SERVICES – METEOROLOGICAL REPORT:
Page 3 of 5.
XXXXXXXX v XXXXXXXXX
During this period I noted that the winds were very slack – often reading zero, but with a general
average close to 3 knots and a maximum of 7.2 knots from a direction of 220 degrees. I
concluded that this was not a safe measurement of prevailing wind strengths of the day.
I then proceeded across the XXXXX and entered XXXXXXXX. I climbed the stairs on the XXXX
corner of the XXXXX to a point roughly 30 feet above the street below, with an exposure to the
south and west. Between 1310 and 1325 GMT I proceeded to take wind measurements. The
wind speeds varied markedly between periods of flat calm and general speeds of 5-8 knots,
broadly from 230 degrees. The maximum gust I attained during that period was 10.5 knots.
I felt this was a more appropriate indication of the prevailing winds than I was able to extract from
the XXXXXXXX, although given the surrounding structures I felt the location was not ideal.
Between 1330 and 1345 GMT I measured the wind speeds XXXXXX – at or around the impact
site in front of the imposing new stand, as far north as the XXXXXXX It was noticeable that for
the vast majority of the period the wind was calm or near calm. I was unable to gauge a definite
wind direction and the strongest wind strength was just 2.8 knots. I concluded that this was not a
safe measurement of the prevailing wind strengths of the day. At the same time I observed the
erratic movement of the flags on the top of the XXXXXXXXX
I then left the stadium with XXXXXXXX and was taken to an open area immediately adjacent to
XXXXXXXXXXX and XXXXXXX, known as XXXXXX. XXXXX is approximately 150 metres from
the ground and the top of the park has an elevation which is roughly parallel to where I was
advised the top of the XXXXXXX was situated. The elevated part of XXXXXXX has an open and
exposed aspect to the south and west and I therefore felt this was an ideal location to take
measurements of the prevailing wind. I did so between 1405 and 1420 GMT when wind speeds
averaged between 8-10 knots with a maximum gust of 15.3 knots and a wind direction of 230-240
degrees. It should be noted that I remained on the ground during this time i.e. I did not elevate
myself by climbing onto walls or buildings and that I would therefore be at a lower level than if a
standard 10 meter high anemometer was used at the same location. In that respect, I
acknowledge the accuracy limitations of a hand-held anemometer for comparison purposes to
that of a standard wind gauge, with an expectation that my readings would read lower than that of
a standard wind gauge, if situated in the same location.
Wind Measurement Comparisons:
Not withstanding the above, I obtained comparative wind readings from the XXXXXX for
XXXXXXX, XXXXXX and XXXXXX. The data is more limited than the original 1998 reports, but
nonetheless indicates a clear pattern of the period -:
The actual wind speeds from XXXXXXXl 96m AMSL-:
1300 GMT 220 deg. 12 knots average sustained – max gust 27 knots.
1400 GMT 230 deg. 9 knots average sustained – max gust < 25 knots.
1500 GMT 240 deg. 9 knots average sustained – max gust < 25 knots.
The actual wind speeds from XXXXXX 96m AMSL-:
1250 GMT 230 deg 13 knots average sustained.
1320 GMT 240 deg. 9 knots average sustained.
1350 GMT 230 deg. 12 knots average sustained.
1420 GMT 230 deg. 14 knots average sustained.
1450 GMT 240 deg 12 knots sustained – max gust 22 knots.
BRITISH WEATHER SERVICES – METEOROLOGICAL REPORT:
Page 4 of 5.
XXXXXXXXXXXX v XXXXXXX
The actual wind speeds from XXXXXXX 107m AMSL-:
1300 GMT 210 deg. 10 knots average sustained – max gust < 25 knots.
1400 GMT 240 deg. 12 knots average sustained – max gust < 25 knots.
1500 GMT 240 deg. 8 knots average sustained – max gust < 25 knots.
Conclusion:
1 a). Measuring wind speed at XXXXX as it now stands and almost certainly as it was then,
does not provide an accurate reflection of the prevailing wind conditions and indeed
would almost certainly result in wind speed assessments notably lower than the actual
prevailing wind conditions.
b). The flags on XXXXXXXX, for example, provide nothing more than general information
to any observer. Given the way in which the wind often reacts with flags positioned on the
top of XXXXXX, the information gained by observing them should not be treated as being
precise and I could make no clear judgment as to precise wind speeds by having regard to
the XXXX during my visit.
c). Although I am unable to comment on the validity of taking measurements from any
truly exposed position on the XXXXX, my own experience of measuring from a limited
vantage point on the roof of the XXXXXXXXXX suggests to me that this position would not
provide an accurate reflection of the prevailing wind conditions in a southwesterly.
d). That the vantage point of nearby XXXXXXXXXXX given an open aspect to the
southwest and a height not dissimilar to that of the XXXXXXXXXX, is a much more
appropriate vantage point than anywhere in the stadium. When comparisons are made
with my own readings taken at XXXXXXXXXX and that of the regional weather stations,
there are strong similarities - both indicating notably higher values than the sites tested by
myself within the ground. However I do accept that because the XXXXXXXXXX has been
replaced by a larger stand, I was unable to measure like for like within the stadium.
e). Given the forecasts produced by the XXXXXXX for the day of the incident and the
relatively low safety thresholds that might curtail the jumps, it would in my view have been
necessary to take all appropriate steps to obtain the best possible measurement of the
wind, at regular intervals, from the most appropriate vantage points – both within and
outside the XXXXXXXXXXX.
2a). Having regard for the above and referring to the wind speeds on the day of the
incident, it would in my view have been reasonable to conclude that nearby XXXXXXXXXX
was likely to have experienced something close to or slightly above what was recorded at
the regional weather stations around the time of the incident, with local topographic
variability and the additional ground to roof height of the stand being the main differences.
BRITISH WEATHER SERVICES – METEOROLOGICAL REPORT:
Page 5 of 5.
XXXXXXXXXXX v XXXXXXX
b). It is also likely that given the comments of XXXXXXXX, the wind inside the stadium
several meters above the pitch conveyed a picture of what could be called ‘impacting
winds’ at times – at least as far as the XXXXX was concerned. However, I would suggest
that wind speeds at XXXXX – particularly off the XXXXX, would have been lower than all
points surrounding.
c). Given the local topography and relationship between XXXXXXXX, XXXX & XXXXX and
the southwesterly winds flowing off XXXXX, down and then up again against the stands, I
would have expected a degree of instability and turbulence, which would have varied but
manifested itself at times in terms of sudden gusts at the top of the windward facing
XXXXXX – and then into and across the ground at a similar level.
Such turbulence in
and around the high structures of XXXXXXXXXX would not be an unusual occurrence on a
day with noteworthy winds.
d). I am in no doubt whatsoever that given the strength and relative gustiness of the
southwesterly winds measured in particular at XXXXX & XXXXXX combined with the local
topography and the barrier/height of the windward facing XXXXXXX, that sustained winds
of greater than 10 knots and occasional gusts in excess of 20 knots would have been a
near certain feature around and above the XXXXXXXXXXXX at the time of the incident.
Although there was likely have been a high degree of variability and unpredictability in the
wind strength (much as I experienced on my own visit), the gusts/turbulence would have
been sufficient at times, (but not necessarily obvious from XXXXXXX) to be of concern not
only to XXXXX in terms of XXX XXX behaviour during the match, as the XXXXXXXX
identified, but more importantly to the XXXXXXX dropping in above the XXXXXX.
This report is a true record of my professional opinion. I understand that it is my duty to assist on
the matters within my expertise and I have complied with that duty to the best of my ability.
I further understand that this duty overrides any obligations to those by whom I have been
instructed and/or paid.
Regards
‘Jim’ N R Dale
Senior Meteorological Observer
BRITISH WEATHER SERVICES