Strong winds/heavy rainfall - 7/8 July 2004

The second half of June and early July 2004 were generally unsettled, with a deep depression passing over England on 23 June. Another depression, coming up from Spain/France, caused high wind speeds and heavy rainfall on 7/8 July. This was followed by heavy showers/thunderstorms over parts of England on 8 July.

Six-hourly animated synoptic charts

assx7_8july04

This unseasonably bad weather resulted in problems for power supplies, on roads and on the railways. There were also flooding problems near Wittering on 8 July, which recorded over 100 mm in just 18 hours, which is double their July 1961-90 average.

Winds

Highest hourly mean wind speeds - 7 and 8 July 2004

Reviewed December 2009.

7 and 8 July 2004 - Highest hourly mean wind speeds
Low-level stations
(below 200 metres)
Station elevation Mean hourly
wind speed (knots)
Hour ending Comments
Berry Head,
Devon
58 m 44 7 July, 
19:00
Previous highest July value was 41 knots on 25 July 2003. Digital data records back to 1994.
Donna Nook,
Lincolnshire
8 m 37 8 July,
07:00
Previous highest July value was 35 knots on 10 July 2000. Digital data records back to 1995.
Mumbles Head,
near Swansea
32 m 36 7 July,
22:00
Highest July value is 39 knots on 11 July 2001. Digital data records back to 2000.
Holbeach,
Lincolnshire
3 m 34 8 July,
02:00
Previous highest July value was 27 knots on 1 July 1992. Digital data records back to 1992.
Langdon Bay,
Kent
117 m 32 7 July, 
13:00
Highest July value is 35 knots on 4 July 1990. Digital data records back to 1985.
Culdrose,
Cornwall
78 m 32 7 July, 
21:00
Highest July value is 38 knots on 23 July 1990. Digital data records back to 1977.

Map of highest hourly mean wind speeds - 7 and 8 July 2004

mean7_8jul04

Highest gust speeds - 7 and 8 July 2004

Reviewed December 2009.

The highest known gust speed anywhere in the UK during July is 81 knots (93 m.p.h.) at The Lizard on 29 July 1956.

7 and 8 July 2004 - Highest gust speeds
Low-level stations
(below 200 metres)
Station elevation Gust speed
(knots)
Hour
ending
Comments
Berry Head,
Devon
58 m 62 7 July, 21:00 Previous highest July value was 54 knots on 25 July 2003. Digital data records back to 1994.
Brixham,
Devon
8 m 60 7 July, 21:00 Previous highest July value was 49 knots on 25 July 2003. Digital data records back to 1997.
Culdrose,
Cornwall
78 m 59 7 July, 22:00 Previous highest July value was 51 knots on 7 July 1991. Digital data records back to 1977.
Mumbles Head,
near Swansea
32 m 55 7 July, 22:00 Previous highest July value was 52 knots on 11 July 2001. Digital data records back to 2000.
Camborne,
Cornwall
87 m 50 7 July, 23:00 Previous highest July value was 47 knots on 7 July 1991. Digital data records back to 1979.
Donna Nook,
Lincolnshire
8 m 50 7 July, 06:00 Previous highest July value was 45 knots on 10 July 2000. Digital data records back to 1995.

Map of highest gust speeds - 7 and 8 July 2004

gust7_8jul04

Rainfall

Rainfall information - 7 July 2004

Reviewed December 2009.

7 July 2004 - Rainfall
Rainfall station Rainfall total (mm) End date/time Approx. return period (years) Comments
Guernsey Airport
(CI)
62.5 8 July,
09:00 - 24 hours
- -
Wittering,
Cambridgeshire
56.6 8 July,
09:00 - 24 hours
16 Seventh-wettest day on record (09-09 GMT), and 2nd wettest day for July. Wettest day was 10  July 1968 with 79.0 mm. Digital records back to 1957.
Jersey Airport
(CI)
51.9 8 July,
09:00 - 24 hours
- -
Andrewsfield,
Essex
43.8 8 July
09:00 - 24 hours
Not significant -
Wattisham,
Suffolk
36.0 8 July,
09:00 - 24 hours
Not significant -
Wittering,
Cambridgeshire
52.6 8 July,
09:00 - 12 hours
22 Fifth-highest standard 12-hour value recorded in any month (fourth-highest in following 12-hour period), and third-wettest for July. Wettest standard 12-hour period recorded in any month is 65 mm on 9 August 2004. Digital 12-hour records back to 1957.
Wittering,
Cambridgeshire
55.2 8 July,
04:00 - 8 hours
24 -

Twelve-hour standard period is defined as 09-21 GMT or 21-09 GMT.

Please note: The return periods have been calculated using the Flood Estimation Handbook method. This gives the likelihood of recurrence at any time of year, rather than for the month in question only. Return periods less than 10 years have been noted as insignificant in the above table.

Rainfall information - 8 July 2004

Reviewed December 2009.

8 July 2004 - Rainfall
Rainfall station Rainfall total (mm) End date/time duration Approx. return period (years) Comments
Wittering,
Cambridgeshire
52.9 8 July,
21:00 - 12 hours
23 Fourth-highest standard 12-hour value recorded in any month, and second wettest for July. Wettest standard 12-hour period recorded in any month was 64.1 mm on 10 July 1968. Digital 12-hour records back to 1957.
Wittering,
Cambridgeshire
51.0 8 July,
15:00 - 2 hours
80 Highest 2-hour total since hourly digital records began in 1980.
Wittering,
Cambridgeshire
31.0 8 July,
15:00 - 1 hour
35 Wettest hourly value since hourly digital records began in 1980. Previous highest hourly total was 27.5 mm on 7 August 2002.
Wittering,
Cambridgeshire
20.0 8 July,
14:00 - 1 hour
Not significant -

Twelve-hour standard period is defined as 09-21 GMT or 21-09 GMT.

Please note: The return periods have been calculated using the Flood Estimation Handbook method. This gives the likelihood of recurrence at any time of year, rather than for the month in question only. Return periods less than 10 years have been noted as insignificant in the above table.

Extra information on Wittering

Wittering recorded 107.4 mm in 19 hours on 7/8 July 2004, which has an approximate return period of 150 years. This amount of rain has not been previously recorded over such a short time frame at Wittering for any month.

Over the first eight days of July, Wittering recorded 121.5 mm, which is 246% of their 1961-1990 July average rainfall.

A short account, from the Senior Met. Officer at Wittering, gives further insight into the event: "The thunderstorm on Thursday afternoon was very localised indeed. I suspect only a few square miles were affected, the area centred on RAF Wittering. The A1 road is adjacent to our entrance and was closed for a while.

"The whole base was flooded with several buildings affected. Ground stroke lightning was also a feature with several 'hits' on the base resulting in damage to electronic equipment.

"The thunderstorm was not advected from elsewhere but appeared to develop over Wittering in a short space of time and then hardly move. Some hail was observed but nothing too intense. The rain was just like standing under a waterfall."

This unseasonably bad weather resulted in problems for power supplies, on roads and on the railways. There were also flooding problems near Wittering on 8 July, which recorded over 100 mm in just 18 hours, which is double their July 1961-90 average.

Winds

Highest hourly mean wind speeds - 7 and 8 July 2004

Reviewed December 2009.

7 and 8 July 2004 - Highest hourly mean wind speeds
Low-level stations
(below 200 metres)
Station elevation Mean hourly
wind speed (knots)
Hour ending Comments
Berry Head,
Devon
58 m 44 7 July, 
19:00
Previous highest July value was 41 knots on 25 July 2003. Digital data records back to 1994.
Donna Nook,
Lincolnshire
8 m 37 8 July,
07:00
Previous highest July value was 35 knots on 10 July 2000. Digital data records back to 1995.
Mumbles Head,
near Swansea
32 m 36 7 July,
22:00
Highest July value is 39 knots on 11 July 2001. Digital data records back to 2000.
Holbeach,
Lincolnshire
3 m 34 8 July,
02:00
Previous highest July value was 27 knots on 1 July 1992. Digital data records back to 1992.
Langdon Bay,
Kent
117 m 32 7 July, 
13:00
Highest July value is 35 knots on 4 July 1990. Digital data records back to 1985.
Culdrose,
Cornwall
78 m 32 7 July, 
21:00
Highest July value is 38 knots on 23 July 1990. Digital data records back to 1977.

Map of highest hourly mean wind speeds - 7 and 8 July 2004

mean7_8jul04

Highest gust speeds - 7 and 8 July 2004

Reviewed December 2009.

The highest known gust speed anywhere in the UK during July is 81 knots (93 m.p.h.) at The Lizard on 29 July 1956.

7 and 8 July 2004 - Highest gust speeds
Low-level stations
(below 200 metres)
Station elevation Gust speed
(knots)
Hour
ending
Comments
Berry Head,
Devon
58 m 62 7 July, 21:00 Previous highest July value was 54 knots on 25 July 2003. Digital data records back to 1994.
Brixham,
Devon
8 m 60 7 July, 21:00 Previous highest July value was 49 knots on 25 July 2003. Digital data records back to 1997.
Culdrose,
Cornwall
78 m 59 7 July, 22:00 Previous highest July value was 51 knots on 7 July 1991. Digital data records back to 1977.
Mumbles Head,
near Swansea
32 m 55 7 July, 22:00 Previous highest July value was 52 knots on 11 July 2001. Digital data records back to 2000.
Camborne,
Cornwall
87 m 50 7 July, 23:00 Previous highest July value was 47 knots on 7 July 1991. Digital data records back to 1979.
Donna Nook,
Lincolnshire
8 m 50 7 July, 06:00 Previous highest July value was 45 knots on 10 July 2000. Digital data records back to 1995.

Map of highest gust speeds - 7 and 8 July 2004

Rainfall

Rainfall information - 7 July 2004

Reviewed December 2009.

7 July 2004 - Rainfall
Rainfall station Rainfall total (mm) End date/time Approx. return period (years) Comments
Guernsey Airport
(CI)
62.5 8 July,
09:00 - 24 hours
- -
Wittering,
Cambridgeshire
56.6 8 July,
09:00 - 24 hours
16 Seventh-wettest day on record (09-09 GMT), and 2nd wettest day for July. Wettest day was 10  July 1968 with 79.0 mm. Digital records back to 1957.
Jersey Airport
(CI)
51.9 8 July,
09:00 - 24 hours
- -
Andrewsfield,
Essex
43.8 8 July
09:00 - 24 hours
Not significant -
Wattisham,
Suffolk
36.0 8 July,
09:00 - 24 hours
Not significant -
Wittering,
Cambridgeshire
52.6 8 July,
09:00 - 12 hours
22 Fifth-highest standard 12-hour value recorded in any month (fourth-highest in following 12-hour period), and third-wettest for July. Wettest standard 12-hour period recorded in any month is 65 mm on 9 August 2004. Digital 12-hour records back to 1957.
Wittering,
Cambridgeshire
55.2 8 July,
04:00 - 8 hours
24 -

Twelve-hour standard period is defined as 09-21 GMT or 21-09 GMT.

Please note: The return periods have been calculated using the Flood Estimation Handbook method. This gives the likelihood of recurrence at any time of year, rather than for the month in question only. Return periods less than 10 years have been noted as insignificant in the above table.

Rainfall information - 8 July 2004

Reviewed December 2009.

8 July 2004 - Rainfall
Rainfall station Rainfall total (mm) End date/time duration Approx. return period (years) Comments
Wittering,
Cambridgeshire
52.9 8 July,
21:00 - 12 hours
23 Fourth-highest standard 12-hour value recorded in any month, and second wettest for July. Wettest standard 12-hour period recorded in any month was 64.1 mm on 10 July 1968. Digital 12-hour records back to 1957.
Wittering,
Cambridgeshire
51.0 8 July,
15:00 - 2 hours
80 Highest 2-hour total since hourly digital records began in 1980.
Wittering,
Cambridgeshire
31.0 8 July,
15:00 - 1 hour
35 Wettest hourly value since hourly digital records began in 1980. Previous highest hourly total was 27.5 mm on 7 August 2002.
Wittering,
Cambridgeshire
20.0 8 July,
14:00 - 1 hour
Not significant -

Twelve-hour standard period is defined as 09-21 GMT or 21-09 GMT.

Please note: The return periods have been calculated using the Flood Estimation Handbook method. This gives the likelihood of recurrence at any time of year, rather than for the month in question only. Return periods less than 10 years have been noted as insignificant in the above table.

Extra information on Wittering

Wittering recorded 107.4 mm in 19 hours on 7/8 July 2004, which has an approximate return period of 150 years. This amount of rain has not been previously recorded over such a short time frame at Wittering for any month.

Over the first eight days of July, Wittering recorded 121.5 mm, which is 246% of their 1961-1990 July average rainfall.

A short account, from the Senior Met. Officer at Wittering, gives further insight into the event: "The thunderstorm on Thursday afternoon was very localised indeed. I suspect only a few square miles were affected, the area centred on RAF Wittering. The A1 road is adjacent to our entrance and was closed for a while.

"The whole base was flooded with several buildings affected. Ground stroke lightning was also a feature with several 'hits' on the base resulting in damage to electronic equipment.

"The thunderstorm was not advected from elsewhere but appeared to develop over Wittering in a short space of time and then hardly move. Some hail was observed but nothing too intense. The rain was just like standing under a waterfall."

Last updated: 10 May 2013