• Abstract and Figures
• Public Full-text

U.S. DEPARTMENT OF COMMERCE FREDERICK H. MuELLER, Secretary WEATHER BUREAU F. W. REICHELDERFER, Chief TECHNICAL PAPER NO. 20 Tornado Occurrences in the United States LAURA V. WOLFORD Office of Climatology WASHINGTON, D.C. Revised 1960 For sale by the Superinten-dent of Documents, U.S. Government Printing Office, Washington 25, D.C. • Pcice 45 cents CONTENTS Page Preface .. 1 Sources and Reliability of Data 1 Tornadoes of Early Years. 2 Tornado Characteristics 2 Pressure. 3 Rates of Travel and Internal Wind Speeds. 4 Direction of Movement 4 Length and Width of Paths 5 Tornado Statistics. 6 Distribution of Tor-nado Occurrences 6 Loss of LifeQ 6 Property Damage 6 Frequency and Time of Occurrence. 7 Tornado Forecasting 7 Tornado OdditiesQ 8 Tornado Occurrences in Major Cities and Selected Communities. 10 Observer's Impressions of Tornadoes 11 Tornado Groups or Families. 12 Waterspouts 12 Tornadoes in Other Countries. 13 References. 14 Tables Table lQ-~Some Outstanding Tornadoes, 1876-1958 16 Table 2.--Number of Tornadoes, Days, Deaths, and Damage for States and United States by Years, 1916-58 20 Table 3.--Number of Tornadoes, Days, Deaths, and Damage for United States by Months,for Years 1916-58 30 Table 4.--Total Number of Tornadoes and Tornado Days by States, and United States Totals and Means» 1916-58Q 34 Table 5.--Total Number of Tornadoes Beginning During the Specified Hours, 1916-58 35 Table Sa--Tornadoes Associated with Passage of Tropical Storms, 1916-58 36 CONTENTS.--Continued Page Table 7.--Tornado Occurrencesm Major Cities and Selected Communities 38 Table 8.--Selected Families of Tornadoes, 1916-58 • • 0 Q 40 Table 9.--List of More Damaging Tornadoes in Each State, 1916-58. 41 Table 10.--Number of Waterspouts and Days for States and United States, 1948-58 • • • • • • • • • • • • • • 48 Table 11.--Number of Funnels Aloft and Days by Months and Years in United States, 1953-58. • • • • • • • • • • • • • • 48 Table 12.--Number of Funnels Aloft for States and United States by Months, 1953-58 • • • • • • • • • • • • • • • 49 Figures Figure I.--Automatic Records of Pressure, Temperature, Rainfall, Wind Direction, and Wind Speed at St. Louis, Mo., May 27, 1896 3 Figure 2.--Barogram Trace at Dyersburg, Tenn., March 21-22, 1952 4 Figure 3.--Tornado Rose for the United States 5 Figure 4.--Mean Monthly Number of Tornadoes in the Alabama-Florida- Georgia-Louisiana-Mississippi Area, 1916-58 ·• • • • • • • 50 Figure 5o--Mean Monthly Number of Tornadoes in the Arkansas-Kansas-Mis- souri-Oklahoma Area, 1916-58. o • • • • o o •• o o 50 Figure 6o--Mean Monthly Number of Tornadoes in the Iowa-Minnesota- Nebraska-North Dakota-South Dakota Area, 1916-58 •• o o 50 Figure 7.--Mean Monthly Number of Tornadoes in the United States, 1916-58 50 Figure So--Mean Monthly Number of Tornado Days in the United States, 1916-58 ••••• 0 •• 0 • • • • • • • • • • • • • • 50 Figure 9.--Mean Monthly Number of Tornadoes per Tornado Day in the United States~ 1916-58 • • • • • • • • • • • • • • • • • • 50 Figure lOo--Total Number of Tornadoes and Tornado Days Recorded on Each Date of the Year in the United States, 1916-58. • • • • 51 Figure lL--Percentage of Tornadoes Beginning During the Specified Hours in the Alabama-Florida-Georgia-Louisiana-Mississippi Area~ 1916-58 55 Figure 12o--Percentage of Tornadoes Beginning During the Specified Hours in the Arkansas-Kansas-Missouri-Oklahoma Area, 1916-58. • • • 55 Figurela--Percentage of Tornadoes Beginning During the Specified Hours m the Iowa-Minnesota-Nebraska-North Dakota-South Dakota Area, 1916-58 e e e 0 o 0 e 0 0 e e o o e 0 0 G 8 Q 0 0 0 56 Figure 14.--Percentage of Tornadoes Beginning During the Specified Hours in the Entire United States, 1916-58 • 56 Figure !~--Tornadoes by 2 Degree Squares, 1916-53 57 Figure 16.--Tornadoes by 1 Degree Squares, 1953-58 58 CONTENTS.--Continued Page Charts Chart 1.--Tracks of January Tornadoes, 1916-58. 59 Chart 2" --Tracks of February Tornadoes, 1916-58 . 60 Chart 3 "--Tracks of March Tornadoes, 1916-58., 0 . 61 Chart 4.,--Tracks of April Tornadoes, 1916-58. 0 62 Chart 5.--Tracks of May Tornadoes, 1916-58. 63 Chart 6.--Tracks of June Tornadoes~ 1916-58 . 64 Chart 7. --Tracks of July Tornadoes~ 1916-58 . 65 Chart B.--Tracks of August Tornadoes, 1916-58 . 66 Chart 9 .--Tracks of September Tornadoes, 1916-58. 0 Q 67 Chart 10.--Tracks of October Tornadoes, 1916-58. 68 Chart 11.--Tracks of November Tornadoes, 1916-58 . 69 Chart 12. --Tracks of December Tornadoes, 1916-58 0 . Q . Q 70 Chart 13.--Tracks of All Tornadoes, 1953-58. • • • 71 Tornado Occurrences in the United States Laura V. Wolford Office of Climatology U. s. Weather Bureau, Washington, D. C. PREFACE This revision of the first edition of and property damage, because of population Technical Paper No. 20 extends the data growths, increased alertness to and general to include the years 1951 through 1958 and interest in these storms~ advances in ob­ contains additional textual material, tabula­ servational techniques~ and changes in tions, and charts. monetary value of property. The primary purpose of this publication Grateful acknowledgment is made to State is to bring up to date the available records Climatologists and other U. S. Weather of all tornadoes in the United States in Bureau personnel at field stations; to the order to provide more useful information tens of thousands of cooperative observers to the public and to business, commerce, and other public spirited persons over the and industry in general regarding the usual country who, through their interest and frequency of tornado occurrences in the cooperative efforts for several generations, different sections of the country. have provided the basic data; to Dr. Helmut The systematic recording and reporting E. Landsberg for general guidance and re­ of tornadoes by the Weather Bureau began in view; to Messers Lilburn H. Seamon, Robert 1916. The detailed statistics presented W. Schloemer, and Milton L. Blanc for herein relative to areal distribution, hours valuable comments; to Miss Marjorie A. Clark of occurrence, loss of life, property dam­ of the Weather Bureau Library for assistance age, and frequency of occurrence are based in research; to the Drafting Section of the on the 43-year period beginning with 1916 Weather Bureau for drafting the figures and and extending through 1958. Funnel clouds charts; and to Mrs. Lola M. Starbuck and Mr. aloft and waterspouts are presented in William T. Pullen for assistance in the separate tabulations and are not included preparation of copy for publication. Plan­ in the tornado summarizations. ning and preparation of this publication It is impractical to make an accurate were under the direct supervision of Mr. comparison of recent tornado data with re­ John L. Baldwin, Chief of Domestic Area ports of previous years~ particularly in Section, Office of Climatology. regard to number of tornadoes, tornado days, SOURCES AND RELIABILITY OF DATA The tornado statistics presented herein storms such as tornadoes before classifying are based upon regular monthly and annual them. The storms recorded here as tornadoes reports of tornadoes prepared by Weather were so classified only if the character­ Bureau State Climatologists or Meteorolo­ istic funnel cloud was plainly seen, or gists in Charge responsible for reporting subsequent examination of the destruction such storms in specific areas (usually a clearly indicated the characteristic whirl­ single State, but in some cases consisting ing motion of the winds, the bursting ef­ of two or more Sta 1es). During the 43-year fects on buildings, or the sucking up of period (1916-1958) covered by this summary, objects into the air as the storm passed. all State Climatologists and Meteorologists It is realized, of course, that the judg­ in Charge were operating under instructions ment of field classifiers of such storms to depend upon only the most reliable and is not infallible, especially in border­ unbiased sources of these data. The prin­ line cases. It is also true that some c ipa 1 sources have been loca 1 Weather Bureau tornadoes occur in areas either uninhabit­ offices, the American National Red Cross ed or where there is no vegetation to in­ Cooperative Weather Observers, State In~ dicate the occurrence, so that some have surance Companies, and Federal, State, gone unrecorded. It is evident, however, County, and Municipal offices. Weather that the increase in the number reported Bureau officials responsible for reporting during ~ecent years, particularly since these data are instructed also to investi­ 1951, is due to increased public awareness gate and fully verify reports of all unusual of tornadoes, establishment of extensive 1 'reporting and warning networks, improved issue of the Climatological Data National methods of tracking tornadoes, better com­ Summary from 1950 through 1958. These munication facilities, and increases in publications constitute the principal population. sources of data for this summary. (Be­ A table of monthly severe storm reports, ginning in 1959 tornado reports are in­ including tornadoes, was published in the cluded in the separate publication, Storm Monthly Weather Review from June 1921 Data, each month.) through December 1949. Since 1949, these In the compilations of these statistics, reports have been published in the Clima­ questionable cases were referred back to tological Data National Summar~. Annual Weather Bureau officials for further in­ summaries of tornado occurrences were pub­ vestigation. If some of the known charac­ lished in the Report of the Chief of the teristics of tornadoes were not found in Weather Bureau from 1916 through 1934, in the original records and notes made at the the United States Meteorological Yearbook time of occurrence, the storm in question from 1935 through 1949, and in the annual was not included in this summary. TORNADOES OF EARLY YEARS Records of tornadoes in this country prior nadoes which occurred in the United States to about 1875 are necessarily meager, for during the period 1682-1874.

Load more

  77

Copy Link