Mississippi State University Scholars Junction Theses and Dissertations Theses and Dissertations 1-1-2004 Dixie alley: Fact or Fallacy : An In Depth Analysis of Tornado Distribution in Alabama Kristin Nichole Hurley Follow this and additional works at: https://scholarsjunction.msstate.edu/td Recommended Citation Hurley, Kristin Nichole, "Dixie alley: Fact or Fallacy : An In Depth Analysis of Tornado Distribution in Alabama" (2004). Theses and Dissertations. 1549. https://scholarsjunction.msstate.edu/td/1549 This Graduate Thesis - Open Access is brought to you for free and open access by the Theses and Dissertations at Scholars Junction. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of Scholars Junction. For more information, please contact [email protected]. DIXIE ALLEY:FACT OR FALLACY AN IN DEPTH ANALYSIS OF TORNADO DISTRIBUTION IN ALABAMA By Kristin Nichole Hurley A Thesis Submitted to the Faculty of Mississippi State University in Partial Fulfillment of the Requirements for the Degree of Master of Science in Geoscience in the Department of Geosciences Mississippi State, Mississippi May 2004 Copyright by Kristin Nichole Hurley 2004 DIXIE ALLEY: FACT OR FALLACY AN IN DEPTH ANALYSIS OF TORNADO DISTRIBUTION IN ALABAMA By Kristin Nichole Hurley ______________________________ ______________________________ Michael E. Brown Charles L. Wax Assistant Professor of Geosciences Professor of Geosciences (Director of Thesis) (Committee Member) ______________________________ ______________________________ John C. Rodgers, III John E. Mylroie Assistant Professor of Geosciences Graduate Coordinator of the Department (Committee Member) of Geosciences ______________________________ ______________________________ Mark S. Binkley Philip B. Oldham Professor and Head of the Department of Dean and Professor of the College of Geosciences Arts and Sciences Name: Kristin Nichole Hurley Date of Degree: May 8, 2004 Institution: Mississippi State University Major Field: Geoscience Major Professor: Dr. Michael E. Brown Title of Study: DIXIE ALLEY: FACT OR FALLACY AN IN DEPTH ANALYSIS OF TORNADO DISTRIBUTION IN ALABAMA Pages in Study: 82 Candidate for Degree of Master of Science Alabama, also known as the Dixie state, is no stranger to severe weather. Severe weather can occur during much of the year. Experienced local forecasters have long suspected that North and Central Alabama has its own tornado alley. Many of these forecasters have noticed storm tracks as well as tornado tracks to be similar to past historic events. Many questions have risen about the exact influential factors that cause convective initiation and tornadic development. For example the effects of terrain, water, and population on tornado climatology will be discussed in this study. The sometimes unreliable climatology of tornadoes will be addressed as well as the history of storm reporting. Tornado clusters were found and further explained regarding relationships with terrain, water, and population. Through this research, it is concluded that there are two distinct tornado regions that exist in North and Central Alabama. ACKNOWLEDGEMENTS I would like to thank my advisor, Dr. Michael E. Brown, for making this thesis and the defense possible. I appreciate all of the hard work and dedication he has contributed to this research. Much appreciation is due for my committee members, Dr. Charles L. Wax and Dr. John C Rodgers, III. I would also like to thank several of my co-workers at the National Weather Service Office in Birmingham, Alabama for giving me words of encouragement daily and keeping me straight on task. The Meteorologist in Charge, Kenneth Graham, also deserves many thanks because if it were not for him, I would not have the opportunities in the National Weather Service as I do today. I would also like to express my gratitude to my parents for their love and support. ii TABLE OF CONTENTS Page ACKNOWLEDGEMENTS........................................................................................... ii LIST OF TABLES......................................................................................................... iv LIST OF FIGURES ....................................................................................................... v CHAPTER I. INTRODUCTION ............................................................................................. 1 Introduction............................................................................................... 1 Objectives ................................................................................................. 3 Hypothesis................................................................................................. 5 II. REVIEW OF LITERATURE ............................................................................ 6 III. DATA AND METHODS .................................................................................. 19 IV. RESULTS AND DISCUSSIONS...................................................................... 22 Spatial Distributions.................................................................................. 22 Temporal Distribution............................................................................... 31 Tornado Threat.......................................................................................... 40 Directional Threat Contours ..................................................................... 61 Inferences and Interpretations................................................................... 64 Future Investigations................................................................................. 76 V. CONCLUSIONS................................................................................................ 79 LITERATURE CITED .................................................................................................. 81 iii LIST OF TABLES TABLE Page 1 Fujita Tornado Intensity Scale........................................................................ 4 2 Raw Data of Counties, County Seats, Latitudes, Longitudes, Population, and Elevation ..........................................................................44 3 ACF Numbers for All Tornadoes for County Seats........................................46 4 Top 15 ACF Numbers for County Seats.........................................................48 5 Bottom 15 ACF Numbers for County Seats ...................................................48 6 County Seats Top 15 in Population illustrated with All ACF Numbers......................................................................................................49 7 County Seats Bottom 15 in Population illustrated with All ACF Numbers......................................................................................................49 8 County Seats Top 15 in Elevation with All ACF Numbers............................50 9 County Seats Bottom 15 in Elevation with All ACF Numbers ......................50 10 ACF Numbers for Significant Tornadoes for County Seats ...........................51 11 Top 15 Significant ACF Numbers for County Seats ......................................53 12 Bottom 15 Significant ACF Numbers for County Seats.................................53 13 County Seats Top 15 in Population illustrated with Significant ACF Numbers .............................................................................................54 14 County Seats Bottom 15 in Population illustrated with Significant ACF Numbers .............................................................................................54 15 County Seats Top 15 in Elevation with Significant ACF Numbers ...............55 16 County Seats Bottom 15 in Elevation with Significant ACF Numbers..........55 iv LIST OF FIGURES FIGURE Page 1 Topography map of Alabama ....................................................................... 2 2 F2 and Greater to All Tornadoes between 1950-1992.................................. 7 3 Annual number of violent, strong, and weak tornadoes in the United States............................................................................................................ 9 4 Tornado path plots for the eastern half of the United States between 1880-1982 ....................................................................................................17 5 Same as Figure 4 only zoomed in for Alabama.............................................18 6 Plot of F0 Tornadoes between 1950-1999.....................................................23 7 Plot of F1 Tornadoes between 1950-1999.....................................................24 8 Plot of F2 Tornadoes between 1950-1999.....................................................25 9 Plot of F3 Tornadoes between 1950-1999.....................................................26 10 Plot of F4 Tornadoes between 1950-1999.....................................................27 11 Plot of F5 Tornadoes between 1950-1999.....................................................28 12 Plot of Significant Tornadoes (F2-F5) between 1950-1999 ..........................29 13 Plot of All Tornadoes (F2-F5) between 1950-1999.......................................30 14 Distribution of All Tornadoes according to Time of Day..............................32 15 Monthly Distribution of All Tornadoes .........................................................33 16 Yearly Distribution of All Tornadoes............................................................34 17 Distribution of Tornado