Extreme Weather Extreme Weather Forty Years of the Tornado and Storm Research Organisation (TORRO) EDITED BY ROBERT K. DOE This edition first published 2016 © 2016 by John Wiley & Sons, Ltd. Registered Office John Wiley & Sons, Ltd, The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, UK Editorial Offices 9600 Garsington Road, Oxford, OX4 2DQ, UK The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, UK 111 River Street, Hoboken, NJ 07030‐5774, USA For details of our global editorial offices, for customer services and for information about how to apply for permission to reuse the copyright material in this book please see our website at www.wiley.com/wiley‐blackwell. The right of the author to be identified as the author of this work has been asserted in accordance with the UK Copyright, Designs and Patents Act 1988. All rights reserved. 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Cover image: 17 April 2008, Dawlish, Devon, U.K. © Matt Clark Set in 9/11pt Times by SPi Global, Pondicherry, India 1 2016 Contents Notes on Contributors xi 3.5 Towards a Climatology of Tornadoes by Synoptic Type 43 Foreword xiii 3.6 Monthly and Annual Frequencies Preface xv of Tornadoes by Synoptic Type 43 3.7 Spatial Distribution of Tornadoes About the Companion Website xvii by Synoptic Type 44 3.8 Morphology of Tornadic Storms 46 1 Researching Extreme Weather in the United 3.9 Association of Supercells Kingdom and Ireland: The History of the Tornado with Giant Hail 47 and Storm Research Organisation, 1974–2014 1 3.10 Case Studies of Supercell and Non‐supercell G. Terence Meaden Tornadoes 48 1.1 Introduction: The Early Years 1 3.10.1 Case 1: The Cold Front of 1.2 International T‐Scale: Theoretical Basis 2 29 November 2011 48 1.2.1 Hailstorm Research 3 3.10.2 Case 2: The English Midlands 1.2.2 Temperature Extremes for the British Isles 3 Supercells of 28 June 2012 51 1.3 Tornado Research Organisation 4 3.10.3 Case 3: The West Cornwall 1.4 The Inaugural Issue of The Journal of Meteorology 4 Supercell of 16 December 2012 52 1.5 Storm‐Damage Site and Track Investigations 6 3.11 Concluding Remarks 55 1.6 Birmingham Tornado of 28 July 2005 8 References 58 1.7 TORRO Conferences 8 1.8 The Future 11 Acknowledgements 13 4 Tornadoes in the United Kingdom Additional information 13 and Ireland: Frequency and References 13 Spatial Distribution 61 Peter Kirk, Tim Prosser, and David Smart Part I TornaDOES 15 4.1 Introduction 61 4.2 The TORRO Database 62 2 Historical tornadoes in the British Isles 17 4.3 Tornado Frequency for the United Kingdom Paul R. Brown and G. Terence Meaden and Ireland: 1981–2010 63 4.3.1 Annual Number of Tornadoes 2.1 Introduction 17 and Tornado Days 63 2.2 Etymology of the Word Tornado 17 4.3.2 Season and Month of Occurrence 64 2.3 Terminology 18 4.3.3 Hour of Occurrence 65 2.4 Accuracy and Completeness of the Records 19 4.3.4 Intensities 65 2.5 Analysis of Historical Tornadoes 20 4.3.5 Track Lengths 65 2.6 Examples of Historical Tornado Reports 21 4.3.6 Maximum Track Widths 65 2.7 Concluding Remarks 30 4.3.7 Directions of Travel 66 References 30 4.4 Spatial Distribution of Tornadoes in the United Kingdom and Ireland 66 3 Supercell and Non‐supercell Tornadoes 4.4.1 Simple Mapping of the Database 66 in the United Kingdom and Ireland 31 4.5 Issues with Mapping 66 Matt Clark and David Smart 4.6 Kernel Density Mapping of Tornado 3.1 Introduction 31 Distribution 70 3.2 Basic Structure and Life Cycle of a Storm Cell 32 4.7 The ‘London Metropolitan’ Anomaly 70 3.3 Storm Mode: An Overview of Single‐Cell, 4.8 The Isle of Wight and South Multicell and Supercell Convection 32 Coast Anomaly 72 3.4 Tornadoes in Supercell and 4.9 Concluding Remarks 73 Non‐supercell Storms 36 Acknowledgements 74 3.4.1 Synoptic Situations Associated Additional Information 74 with Tornadoes in the United Kingdom 40 References 75 v vi Contents 5 Tornado Extremes in the United Kingdom: 8 Thunderstorm Observing in the United Kingdom: The Earliest, Longest, Widest, Severest A Personal Diary of Days with Thunder 1953–2013 135 and Deadliest 77 Bob Prichard Mike Rowe 8.1 Introduction 135 5.1 Introduction 77 8.2 Early Observations 135 5.2 Earliest Tornado 77 8.2.1 Thunderstorm Observing 136 5.3 Other Whirlwinds (First UK Record Only) 79 8.3 Thunderstorms of the 1960s 137 5.4 Longest Tornado Track 80 8.3.1 The ‘Days with Thunder Heard’ Statistic 140 5.5 Widest Tornado Track 82 8.3.2 Back to the 1960s 140 5.6 Severest Tornado 83 8.4 Thunderstorms of the 1970s 141 5.7 Largest Outbreaks 88 8.5 Thunderstorms of the 1980s 143 5.8 Highest Death Toll 89 8.6 The Forecasting of Thunderstorms 145 5.9 Concluding Remarks 89 8.7 Back to the 1980s 146 Acknowledgements 89 8.8 Thunderstorms of the 1990s 147 References 89 8.9 The Most Recent Thunderstorms: 2000–2013 150 8.10 Concluding Remarks 154 References 154 6 Site Investigations of Tornado Events 91 John Tyrrell 9 Severe Hailstorms in the United Kingdom 6.1 Introduction 91 and Ireland: A Climatological Survey with Recent 6.2 Getting Started: How Site Investigations and Historical Case Studies 155 Come About 92 Jonathan D.C. Webb and Derek M. Elsom 6.3 Site Investigation Methods 92 6.4 Site Investigation Outcomes: The Growing 9.1 Introduction 155 Understanding of UK Tornadoes 94 9.1.1 Establishment of a Tornado and Storm 6.5 Site Investigation Experience 101 Research Organisation Research 6.6 Concluding Remarks 102 Database of Hail Events 155 Acknowledgements 103 9.2 Assessing the Intensity of Hail Falls 155 References 103 9.2.1 Hailstorm Intensity Scale 155 9.2.2 Kinetic Energy 156 9.2.3 Hailstone Size and Damage 156 Part II THUNDerstorMS AND 9.2.4 Other Factors Affecting Damage 156 LIGHTNING 105 9.3 Annual Frequency of Hail 157 9.3.1 All Significant, Damaging Hailstorms 157 9.3.2 Frequency of Extreme, Destructive 7 Epic Thunderstorms in Britain and Ireland 107 Hailstorms 158 Jonathan D.C. Webb 9.3.3 Comparisons with Continental Europe 159 7.1 Introduction 107 9.4 Seasonal Occurrence of Hail 159 7.2 Selected Epic Thunderstorm Events 109 9.4.1 General Seasonal Incidence of Hail 7.2.1 2–3 August 1879 109 and Damaging Hailstorms 159 7.2.2 5–10 June 1910 110 9.4.2 Storms of H5 Intensity or More 159 7.2.3 7–10 July 1923 114 9.4.3 Comparison with the Incidence 7.2.4 17–18 July 1926 114 of Thunderstorms 159 7.2.5 28–29 August 1930 114 9.5 Geographical Distribution 160 7.2.6 18–22 June 1936 116 9.5.1 Storms of H2 Intensity or More 160 7.2.7 The West Country Thunderstorm 9.5.2 Geographical Distribution of Storms of 4 August 1938 119 of H5 Intensity or More 161 7.2.8 5 September 1958 123 9.5.3 Point Frequencies 161 7.2.9 22–24 June 1960 125 9.5.4 European Comparisons 161 7.2.10 8–9 August 1975 125 9.6 Hailstorm Characteristics 161 7.2.11 13–14 June 1977 126 9.6.1 Hail Swathes 161 7.2.12 25–26 July 1985 127 9.6.2 Radar and Hail Swathe Identification 163 7.2.13 24 May 1989 128 9.6.3 Results of Hail Swathe Analyses 163 7.2.14 8–9 August 1992 131 9.7 Synoptic Weather Types and Hailstorms 164 7.2.15 24 June 1994 132 9.7.1 Specific Synoptic Background to 7.3 Concluding Remarks 132 Hailstorms 164 Acknowledgements 132 9.8 Hour‐of‐Day Distribution 167 References 132 9.9 Summary of TORRO’s Overall Findings 168 Contents vii 9.10 Twenty of the Most Severe Hailstorms 169 10.11 Fewer Deaths from Lightning Over Time 203 9.10.1 1687: The Alvanley Storm 169 10.12 Lightning Strikes to Animals 204 9.10.2 1697: Remarkable Late Spring 10.13 Lightning Impacts on Aircraft and Storms 169 Motor Vehicles 205 9.10.3 1763: The Great Kent Storm of 10.14 Increasing Awareness of the Lightning Risk 206 19 August 169 Acknowledgements 206 9.10.4 1808: The Great Somerset References 206 Hailstorm of 15 July 169 9.10.5 1818: