January 1809: Synoptic Meteorology of Floods and Storms Over Britain
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OCCASIONAL PAPERS ON METEOROLOGICAL HISTORY No.16 JANUARY 1809: SYNOPTIC METEOROLOGY OF FLOODS AND STORMS OVER BRITAIN DAVID E PEDGLEY Published by The Royal Meteorological Society’s History of Meteorology and Physical Oceanography Special Interest Group JULY 2015 ISBN: 978-0-948090-40-0 ROYAL METEOROLOGICAL SOCIETY 104 OXFORD ROAD – READING – RG1 7LL – UNITED KINGDOM Telephone: +44 (0)118 956 8500 Fax: +44 (0)118 956 8571 E-mail: [email protected] Web: http://www.rmets.org Registered charity number 208222 © Royal Meteorological Society 2015 i JANUARY 1809: SYNOPTIC METEOROLOGY OF FLOODS AND STORMS OVER BRITAIN David E Pedgley Aquatint by Robert Havell the younger of Wallingford Bridge in 1810 illustrating an early stage of reconstruction. Royal Meteorological Society July 2015 ii CONTENTS LIST OF FIGURES ............................................................................................................... ii LIST OF TABLES ................................................................................................................. iii LIST OF SYNOPTIC CHARTS ................................................................................................ iii INTRODUCTION ................................................................................................................ 1 THE FLOODS: WIDESPREAD DISASTER .............................................................................. 3 THE WEATHER: SNOW, FREEZING RAIN AND GALES ......................................................... 15 Over land .................................................................................................................... 16 At sea ......................................................................................................................... 16 THE SYNOPTIC CHARTS ..................................................................................................... 22 Synoptic patterns ....................................................................................................... 23 14-15 January 1809: the first snowy spell ................................................................... 24 16-18 January 1809: a dry interval with severe frost in Scotland ................................ 26 19-20 January 1809: ice storm, widespread freezing rain ........................................... 27 21 January 1809: continued severe frost in Scotland .................................................. 30 22 January 1809: another snowy spell (and the army’s retreat from Corunna) ........... 30 23 January 1809: quiet, but frosty .............................................................................. 32 24-25 January 1809: wreck of the East Indiamen ‘Admiral Gardner’ and ‘Britannia’ .... 32 26-28 January 1809: spread of the thaw ..................................................................... 35 29 January 1809: a severe gale ................................................................................... 36 30 January 1809: hurricane force winds ..................................................................... 38 31 January 1809: a pleasant day at last ....................................................................... 44 CONCLUSIONS .................................................................................................................. 45 ACKNOWLEDGEMENTS .................................................................................................... 46 REFERENCES ..................................................................................................................... 46 LIST OF FIGURES Fig.1 Aquatint by Robert Havell the younger of Wallingford Bridge in 1810 illustrating an early stage of reconstruction. ............................................................................. 4 Fig.2 Places in the Thames valley where flooding was recorded in January 1809. ............. 5 Fig.3 Places across Britain where flooding was recorded in January 1809. For additional places in the Thames valley, see Fig.2. ..................................................................... 8 Fig.4 Places with daily records of the weather in January 1809. ....................................... 17 Fig.5 Example pages from Royal Navy ships’ log-books used in this study (courtesy of The National Archives): 5(a) HMS Weazle, south-west of the Lizard 22 January 1809 (TNA: ADM51/2972) .. 19 5(b) HMS Euryalus, in the southern North Sea 25 and 26 January 1809 (TNA: ADM51/1862) .. 20 Fig.6 Places where Royal Navy ships were moored or at anchor during January 1809. ..... 24 Fig.7 Records of freezing rain and hail (ice pellets) during the afternoon and evening of 19 January 1809. ................................................................................................. 29 iii LIST OF TABLES Table A Observations at Mongewell (2 km south of Wallingford, Oxfordshire), at 8 am, 2 pm and 8 pm, 14-31 January 1809 .................................................. 47 Table B Places with quantitative measurements .......................................................... 49 Table C Weather records of eight ships in the western entrance to the English Channel, 14-15 January 1809 .............................................................. 50 Table D Weather records of six ships in The Downs, off the east coast of Kent, 14-15 January 1809 ......................................................................................... 51 Table E Weather records of ten ships around the east coast of Kent, 19-20 January 1809 ......................................................................................... 52 Table F Weather records of ten ships clustered around 49ºN 5ºW, 21-22 January 1809 ......................................................................................... 53 Table G Weather records of ten ships from Corunna passing through 49ºN 5ºW, 21-22 January 1809 ......................................................................................... 54 Table H Weather records of ships near the wrecking on the Goodwin Sands, 24-25 January 1809 ......................................................................................... 55 Table I Weather records of ships in the English Channel, 29 January 1809 ................. 56 Table J Weather records of ships in the English Channel, 30 January 1809 ................. 58 LIST OF SYNOPTIC CHARTS All morning charts 14 January 1809 ............................................................................................................... 60 15 January 1809 ............................................................................................................... 61 16 January 1809 ............................................................................................................... 62 17 January 1809 ............................................................................................................... 63 18 January 1809 ............................................................................................................... 64 19 January 1809 ............................................................................................................... 65 20 January 1809 ............................................................................................................... 66 21 January 1809 ............................................................................................................... 67 22 January 1809 ............................................................................................................... 68 23 January 1809 ............................................................................................................... 69 24 January 1809 ............................................................................................................... 70 25 January 1809 ............................................................................................................... 71 26 January 1809 ............................................................................................................... 72 27 January 1809 ............................................................................................................... 73 28 January 1809 ............................................................................................................... 74 29 January 1809 ............................................................................................................... 75 30 January 1809 ............................................................................................................... 76 31 January 1809 ............................................................................................................... 77 iv January 1809: Synoptic Meteorology of Floods and Storms over Britain by David E Pedgley 2015 ISBN: 978-0-948090-40-0 1 January 1809: synoptic meteorology of floods and storms over Britain David E Pedgley Introduction Towards the end of January 1809 severe and damaging floods affected large areas of Britain. This paper examines the extent, intensity and consequences of the floods, illustrated by numerous newspaper reports (with their well-recognised drawbacks) which attributed them to a rapid thaw of lying snow. It then looks at the weather systems leading up to the floods, based on daily weather observations made at a network of land stations, supplemented by abundant Royal Navy ships’ log-books. After starting as a simple enquiry into the weather leading to the collapse of a particular bridge, at