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The Massive Tornado Outbreak of May 2003 The Massive Tornado Outbreak Of May 2003 A thesis presented to the Faculty of the Graduate School University of Missouri—Columbia In Partial Fulfi llment For The Requirements Of The Degree Of Masters Of Science by ANDREW KUNZ Dr. Anthony Lupo, Thesis Supervisor December 2005 © 2005, Andrew Kunz. All Rights Reserved. The undersigned, appointed by the Dean of Graduate School, have examined the thesis entitled: THE MASSIVE TORNADO OUTBREAK OF 2003 Presented by Andrew Kunz A Candidate for the Degree of Masters of Science. And hereby certify that in their opinion it is worthy of acceptance. Dr. James T. Moore, Professors of Meteorology at Saint Louis University Dr. Anthony R. Lupo, Associate Professor of Soils, Environment & Atmospheric Science at the University of Missouri - Columbia Dr. Patrick S. Market, Associate Professor of Soils, Environment, & Atmospheric Science at the University of Missouri - Columbia Dr. Milon F. George, Professor of Forestry at the University of Missouri - Columbia Thesis ii Acknowledgements I wish to thank the following people, groups, and institutions for all of their help, support, and patience they’ve had with me. My parents, Paul & Sumalee Kunz for thirty years of suffering, complaining, encouraging, and being patient with me as I chase this crazy dream of mine. My advisor, Dr. Anthony Lupo, for being my advisor, agreeing to help me in an area that is not exactly his area of expertise and also for allowing me to do the brunt of the work and being patient with me when I had my moments of stubbornness. The National Weather Service and the University Corperation of Atmospheric Research (UCAR) for their gracious use of their images seen in this thesis. The members of the National Weather Association, for their extremely warm greeting and support when the Powerpoint presentation, which this thesis is an expansion of, failed to appear at their Yearly General Meeting and I had to work without a net. Thesis iii Public Abstract Andrew Kunz MS Atmospheric Science The Massive Tornado Outbreak Of May 2003 Advisor: Dr. Anthony R. Lupo 09.09.2005 Advisor’s Signature Date Graduation Term: Fall 2005 (December 2005) In May of 2003, 516 tornadoes touched down in the central portion of the United States, which is a record for the most tornadoes for any single month. There were fourteen deaths associated with those tornadoes. This thesis examines the events that led up to this massive outbreak at all spatial and temporal scales. For a while, meteorologists were aware that the possibility of severe weather existed; they could not have foreseen the massive number of severe weather events that would occur. This thesis examines many possible factors. In particular, a rare phenomena known as “double blocking” is diagnosed. The paper also takes a critical look at the timing of the event. A comparison of this outbreak to the May 2004 outbreak is made as it was fairly similar. An improved analysis of how such a large amount of severe weather could happen in such a short time period will better help the operational community to be prepared if another tornado outbreak of this kind occurs, even if it is not of quite the same scale as this one. Thesis iv Table of Contents Acknowledgements ............................................................................................................ ii Public Abstract .................................................................................................................. iii Table of Contents ..............................................................................................................iv List of Figures .....................................................................................................................v Academic Abstract ............................................................................................................ ix 1. Introduction .....................................................................................................................1 2. Data & Methodology .......................................................................................................6 a. Data.......................................................................................................................6 b. Methology .............................................................................................................6 i. Lyapunov Exponents ......................................................................................... 10 ii. Phase Diagram ..................................................................................................13 3. Large Scale Discussion ................................................................................................ 15 4. Small Scale Discussion ................................................................................................ 24 a. Synpotic-Scale Events .......................................................................................24 b. Sounding Events ............................................................................................... 32 c. Lyapunov Exponents (Fluid Trapping) ............................................................ 35 d. Forecasting Implication .................................................................................... 39 5. Conclusion .................................................................................................................... 43 References and Work Cited ............................................................................................. 45 Vita ................................................................................................................................... 49 Thesis v List of Figures 1.1 Preliminary Severe Weather Reports as it was given for the days from May 4th through May 9th. Images courtesy of the National Weather Service, © 2005. ... 2 2.1 The Blocking Strength of the fi ve blocks. Block 1 lasted from 23 April - 5 May; Block 2 lasted from 27 April - 3 May; Block 3 lasted from 5 - 13 May; and Block 4 lasted from 10 - 17 May. .................................................................................... 10 2.2 The blocking strength as measured in twelve-hour intervals. ........................... 10 3.1 500 hPa geopotential heigh diagrams, minus the the height countours on 23 April 2003 at 0000 UTC. The indicates the fi rst blocking high. Image provided by the NOAA-CIRES Climate Diagnostic Center, © 2005. .................................16 3.2 500 hPa geopotential heigh diagram on April 25, 2003 at 0000 UTC. The and indicates the blocking highs. Image provided by the NOAA-CIRES Climate Diagnostic Center, © 2005. ...................................................................................17 3.3 Top + Mean Geopotential Heights at 12 hour intervals, starting at April 20th. The colors represent the average height over North America at various boxed latitudes segments: Red: 40° Lat × 60° Long.; Blue: 30° Lat × 50° Long.; Green: 25° Lat × 40° Long.; Magenta: 15° Lat × 30° Long.; Cyan: 10° Lat × 25° Long.; Bottom + The Average Geopotential Height segmented 40° Lat × 60° Long. boxes. ...................................................................................................................... 18 3.4 Tornado reports divided up by the dates for the month of May 2003 and 2004 respectively. Please note that only the preliminary data was used. Data courtesy of the Storm Prediction Center in Norman, Oklahoma. ..................................... 19 3.5 500 hPa map for 3 May 2003 @ 0000 UTC. and indicate the two blocking areas. Image provided by the NOAA-CIRES Climate Diagnostic Center, © 2005. ............................................................................................................................... 20 3.6 This phase diagram map shows the fi rst deviation of height with respect to time versus the height of the blocks. This phase diagram is for the period of 25 April Thesis vi - 20 May 2003; blocks were measured at the 500 hPa level (meters). ............... 21 4.1 The surface, 850 hPa, 500 hPa, and 300 hPa maps respectively for 1 May at 0000 UTC. Included in this maps are the following variables. A) sea level pressure, thickness (contoured every 4 hPa) and precipitable water (mm, contoured every 12.5 mm); B) Heights (30 gpm), temperatures (K, 5 K), and wind vectors at 850 hPa; C) Heights (60 gpm), vertical velocities (μbar s-1) and wind vectors at 500 hPa; D) Heights (120 gpm) and winds (ms-1) at 300 hPa. ................................... 25 4.2 The surface, 850 hPa, 500 hPa, and 300 hPa maps respectively for 4 May at 0000 UTC. Included in this maps are the following variables. A) sea level pressure, thickness (contoured every 4 hPa) and precipitable water (mm, contoured every 12.5 mm); B) Heights (30 gpm), temperatures (K, 5 K), and wind vectors at 850 hPa; C) Heights (60 gpm), vertical velocities (μbar s-1) and wind vectors at 500 hPa; D) Heights (120 gpm) and winds (ms-1) at 300 hPa. ................................... 26 4.3 The surface, 850 hPa, 500 hPa, and 300 hPa maps respectively for May 5th at 00:00 UTC. Included in this maps are the following variables. A) sea level pressure, thickness (contoured every 4 hPa) and precipitable water (mm, contoured every 12.5 mm); B) Heights (30 gpm), temperatures (K, 5 K), and wind vectors at 850 hPa; C) Heights (60 gpm), vertical velocities (μbar s-1) and wind vectors at 500 hPa; D) Heights (120 gpm) and winds (ms-1) at 300 hPa. ...........27 4.4 A Skew-T diagram from
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