Catastrophic Michigan Tornadoes,

Transcription

1 Catastrophic Michigan Tornadoes, George M. Howe and Carl F. Ojala Department of Geography and Geology Eastern Michigan University During the 35-year period from 1950 through 1984, 520 tornadoes were reported and confirmed in Michigan. Slightly less than one quarter of them killed a total of 234 people, injured 3,102, and caused hundreds of millions of dollars in property damage.' A violent tornado in Genesee County on June 8,1953, widely referred to since then as "The Flint Tornado," was responsible for 116 deaths, the greatest number of deaths by a single tornado in the entire United States that year. The worst in Michigan's history, the Flint Tornado death toll ranks fourth largest in the nation, by single tornadoes, for the 69 years from 1916 through It was exceeded only by the record-length Tri-State Tornado which devastated Missouri, Illinois, and Indiana in 1925 (689 deaths), the Tupelo (Mississippi) Tornado in 1936 (216 deaths), and the Woodward (Oklahoma) Tornado in Texas, Oklahoma, and Kansas in 1947 (169 deaths). Because of the Flint Tornado and an outbreak of killer tornadoes in April 1965, Michigan ranks third in the country, after Texas and Mississippi, for total number of tornadocaused deaths from 1953 through Nevertheless, it is the authors' contention that risk of injury or death by tornado in the state is not as high as the preceding might imply. Michigan's tornado history shows that even the densely populated southern third of the Lower Peninsula is at the margin of the United States Tornado Alley, the major tornado region extending northeastward from Texas. The annual number of tornadoes in Michigan ranged from none, in 1950 and 1952, to 39 in 1974 (Table 1). The rather dramatic difference in the number reported each year between and may be at least partly due to increased awareness of tornadoes brought about by watches and warnings issued by the National Weather Service. Despite the much larger number of tornadoes in the latter period, the number of persons killed and injured has been only a small fraction of the toll prior to Michigan's 'tornado season' runs from mid-march into September (Table 1). In 44

2 Number of Tor-nadoe s, YR J F M A M J J A S 0 N D TOT III ' C> ) -' ' Total TABLE 1 Number of tornadoes in Michigan by month and year, II) tornadoes are more likely to occur in mid- and late summer. In overall spatial distribution within the state, there is a noteworthy decrease in number of tornadoes from south to north. Approximately three-quarters of all those reported from 1950 through 1984 oc- curred south of a line from Muskegon County to Bay County, i.e., within Re- gions III and IV in Figure 1. While a majority of the southern four tiers of coun- ties experienced 10 to 16 tornadoes during the 35-year period, the greatest numbers were reported in the southwestern and southeastern corners of the addition to recording the state's most disastrous tornado, June has experienced by far the greatest monthly number of tornadoes in Michigan. The two months before June and the two months after June have all had quite similar second-ranked frequencies. However, the record of Michigan's monthly tornado frequency is not complete until spatial distributions are considered (Figure 1). Southwestern Michigan (Region IV) has experienced its greatest number in April, whereas in the southeastern part of the state (Region III) June has had most. Farther north in the state (Regions I and 45

3 PERCENT OF MICHIGAN TORNADOES BY REGION !! I,! 0 50 Mil E S REGION REGION II % ~:I :: III "1 :: REGION REGION IV "I ~~. 111 M A M J J A S MONTH...,c:tI t o S e ptemb e, O nl, EVA RIGGS Figure 1. Regional distribution of tornadoes, March to September. state (Berrien, Hillsdale, Lenawee, Monroe, Wayne, and Washtenaw) and in Genesee County, from 17 to 23 per county. In Reg ion II, the northern half of the Lower Peninsula, county totals dropped from 5-6 at mid-state to 3 in northernmost counties; however, Lake and Oscoda Counties had none. The Upper Peninsula (Region I) had less than five percent of Michigan's tornadoes, with Keweenaw and Houghton Counties reporting none and the rest of the counties only 1 to 4 in 35 years. Tornadoes vary widely in size, lengt h of their ground contact path, intensity, and therefore in the amount of damage caused. Based on a scale devised by T. Fujita,3 tornadoes have been catego- 46

4 rized as weak, strong, and violent. Weak tornadoes may cause some damage to chimneys or peel off roofs, break branches off trees, push moving cars off roads, and overturn mobile homes. Strong tornadoes can tear roofs off frame houses and some walls off well-constructed houses, overturn trains, uproot forests, and lift and throw even heavy automobiles. Violent tornadoes cause devastation and incredible damage, leveling well-constructed houses and lifting strong frame houses off their foundations and distintegrating them. More than 300 tornadoes, almost 60 percent of the tornadoes in Michigan from 1950 through 1984, were in the weak classification, 191 (37 percent) were strong, and 21 (4 percent) were violent (Table 2). The state has had a statistically significant larger proportion of strong and violent tornadoes than the nation as a whole (41 % vs. 34%). This is related to its high ranking in number of tornado deaths, because most of the tornadoes which killed people, as well as four/ fifths of those causing injury, were in these categories (Table 2). With respect to monthly distribution, one-half of the violent tornadoes in Michigan have occurred in April and the majority of the remainder in May and June. Nearly six/ tenths of all strong tornadoes in the state were experienced in the same three months. Ninety-six percent of Michigan's tornado deaths have been in Regions III and IV, the southern half of the Lower Peninsula. Fifty-one percent occurred in Genesee County alone, caused by the infamous Flint Tornado (Figure 2). Several counties in the southern Lower Peninsula have had large numbers of tornado-caused injuries, and 53 counties in the state have had at least one injury by tornadoes (Figure 2). Fifty tornadoes, less than 10 percent of the 520 reported from 1950 through 1984, caused 96 percent of all tornado deaths and 94 percent of all tornado injuries in the state during that period (Table 3). These are truly the catastrophic tornadoes in Michigan's recent history. They occurred on only 12 days, on 11 of which there were outbreaks of two or more killing and/or injuring tornadoes. All twenty-one of the violent tornadoes wrought their destruction on Michigan on those 12 days. In fact only four tornadoes on three of those days caused 76 percent of all deaths and only seven (including the four killer storms above) on five days resulted in 73 percent of all injuries during the entire period from 1950 to The paragraphs which follow provide details on these twelve catastrophic tornado days in Michigan, in rank order of their destructiveness to people in the state. Numbers in these reports may differ from those in Table 3 because the outbreaks often included tornadoes that did not kill or injure people. June 8, 1953: Eight tornadoes in AIcona, Genesee, Huron, losco, Lapeer, Livingston, Monroe, and Washtenaw Counties NUlber of Tornadoes Total Ki llers Injurers ea k Bl IS 3eB 2 24 Strong 15 3B VIolent IS 19 Totals B8 124 Bl TABLE 2 Konthly and annual nulbers of Weak, Strong, VIolent, Kill er, and Injurer Tornadoes in Kich i gan frol 1958 through 19B4. 47

5 TORNADO DEATHS AND INJURIES IN MICHIGAN ! I I!, o 50 MIL E S Deaths Inj uries EVA R IGGS Figure 2. Number of tornado deaths and injuries by county. Those counties left blank had no deaths and no injuries. This outbreak included the Flint Tornado, the worst tornado in the entire United States since 1950 in terms of number of people killed. A strong cold front, moving eastward from the northern plains, caused tornadoes throughout the central Great Lakes region. The fol- lowing report appeared in Weatherwise: 4 "The greatest disaster in terms of human life (in the outbreak of June 8, 1953) descended on the residential suburbs of the great industrial city of 48

6 ~, Date No. of Ki lling and/or- No. Ki 11 ed No. Injur-ed Injur-ing Tor-nadoes May 21, JLIn 8, Apr-..,. -', ,. '-' i'1ay 12, May 8, ,. '-' Apr- 11, Apr- 21, Jul 4, Apr- 3, Mar- 2121, ,;. 58 Apr- 2, 1977 '"..J 62 May 13, Totals 5tlJ Per-cent of tor-nadoes TABLE 3 Number killed and injured by Michigan's catastrophic tornadoes, Flint, Michigan, at 2040 EST, when a funnel whirled down Coldwater Road for a distance of eight miles. Over 200 homes on either side of the road were reduced to matchwood as 113 persons lost their lives in these minutes of tragedy. The tornado hedge-hopped across the Michigan countryside to the southern end of Lake Huron, only 10 miles north of the Port Huron-Sarnia area where an earlier tornado (21 May) had caused extensive damage on both sides of the international border. Another twister was spotted further north on the evening of 8 June in the vicinity of Saginaw Bay. But the activity soon declined, as is typical of the diurnal trend in tornado frequency, thereby sparing Ontario and New York State from visitations as the frontal system passed over." April 11, 1965: Seventeen tornadoes in Allegan, Barry, Bay, Clinton, Gratiot, Hillsdale, Kalamazoo, Kent, Lenawee, Monroe, Montcalm, Shiawassee, and Tuscola Counties Michigan's greatest tornado outbreak was part of the Palm Sunday Outbreak which included a total of 47 twisters in 49 1

7 Wisconsin, Iowa, Illinois, Indiana, Ohio, and Michigan. This outbreak was one of the largest and most destructive on record up to that time, but was eclipsed by the Super Outbreak in April 1974 (referred to below). A Weatherwise article,s summarizing this series, said : " A total of 257 persons was killed and more than 3,000 injured, Indiana bearing the brunt of these terrible catastrophes. Damage and destruction to property was estimated in excess of a half billion dollars. Of these storms, the one (reports indicate there may have been two) which struck in Branch, Hillsdale, Lenawee, and Monroe Counties, Michigan, was especially noteworthy since it was the most destructive of the year. It killed 44 and injured 612 persons, causing 148 to be hospitalized. Homes totalling 564 were destroyed, while 1026 homes and other buildings were damaged. Many cars, trucks, and boats were demolished, total damage to property being estimated in excess of $500 million." The paths of the two tornadoes in Branch, Hillsdale, Lenawee, and Monroe counties were 87 and 81 miles long, record lengths for Michigan. The following description treats them as one storm. " Path of tornado extended from East Gilead northeastward through Manitou Beach to 10 miles east of M ilan. Homes destroyed, 198 in Branch County, 177 in Hillsdale County and 189 in Lenawee County. One hundred and forty eight persons were hospitalized. There were 1026 buildings and homes damaged throughout the four counties. Roofs and walls were torn off buildings and carried aloft some distance away. Contents of dwellings and buildings were mostly destroyed due to being blown about and carried aloft in the air for considerable distances. Cars, trucks, and boats demolished, tossed and carried aloft in the air for several blocks or more.,,6 Kent and Ottawa counties were struck by another killer tornado, about which this report was published: " Path of tornado extended from Lamount through the northern suburbs of Grand Rapids to near Evans. Thirty two homes destroyed and 192 dwellings were damaged in Kent County. In Ottawa County, two homes were destroyed and 14 dwellings were damaged. Numerous farm buildings were damaged and many were destroyed. Twenty three persons of the 142 injured were hospitalized. Walls and roofs of dwellings were torn off and tossed into the air and carried aloft for several city blocks or more. Contents of homes destroyed and also carried aloft for some distance. Cars and house trailers were demolished and blown about by the terrific tornadic winds. Power and phone service disrupted throughout the area due to poles being blown down and lines severed by the high winds."6 April3, 1956: Three tornadoes in Allegan, Barry, Benzie, Grand Traverse, Kent, Leelanau, Manistee, Montcalm, Ottawa, and Van Buren Counties According to an account in the Detroit Fret:! Press/ these tornadoes "1-Sent more than 200 to hospitals for treatment of injuries. 2-Left an estimated 2000 homeless 3-Caused property damage estimated in excess of 10 million dollars 4-Left a tangle of wreckage that made probing for additional bodies doubly difficult for rescue crews." "The massive storm originated on Lake Michigan, south of Holland. It hit scattered farms, brushed up to the edge of Holland where it destroyed a plumbing warehouse and then veered to the northeast." 50

8 Five of the dead " were counted in an area around Standale, a suburb five miles west of Grand Rapids where a trailer camp was flattened." May 8, 7964: Six tornadoes in Alger, Antrim, Grand Traverse, Macomb, Monroe, and Oakland Counties One tornado moved from Alger into Antrim County while the other listed counties had one tornado each. All of the deaths and all but two of the injuries were in Macomb County. There was one injury in Monroe County and one in Oakland County. At least nine of the eleven deaths were in Chesterfield Township, situated on Anchor Bay. The injured were treated at hospitals in Mt. Clemens and at the hospital at Selfridge Air Force Base. May 72, 7956: Ten tornadoes in Clinton, Genesee, Gratiot, Livingston, Montcalm, Oakland, Saginaw, Shiawassee, and Wayne Counties This outbreak included the second catastrophic tornado to pass through part of Genesee County within three years. It killed three and injured 116 in that county, most of them in a residential section in the southeastern corner of Flint. " An estimated 40 homes and a church were flattened in Lincoln Park. And in Allen Park, a drive-in restraurant was wrecked and power lines were knocked down. " Four persons were hospitalized after three houses were demolished at South Lyon, in southwestern Oakland County." " Widely scattered sightings of funnel-shaped clouds and severe wind storms spread terror throughout Michigan." s May 73, 7980: Two tornadoes in Kalamazoo and Van Buren Counties All five of the deaths and 79 of the 94 injuries caused by these two tornadoes were in Kalamazoo. The "tornado went through center of (the) city. 2 churches, 47 homes, 2 factories, 22 buildings destroyed houses, 156 busi nesses, 4 factories, 5 public buildings damaged persons homeless." g May 27, 7953: One tornado in St. Clair County Two-thirds of St. Clair County's tornado injuries in thirty-five years were recorded in this one tornado. It was the first catastrophic tornado in Michigan in the period. March 20, 7976: Five tornadoes, one each in Calhoun, Ionia, Macomb, and Oakland Counties and one in Eaton and Ingham Counties The two tornadoes in the southeastern corner of the state were the catastrophic ones, each killing one person. The Oakland County tornado, which also injured 55, was summarized as follows: " Touched down in a creek bed just west of small residential area and proceeded northeast to a major business intersection and then through another large residential street complex. In the residential areas, it damaged 91 homes, 35 heavily. Six homes were totally destroyed. 3 business buildings destroyed and 20 damaged at the intersection. It then lifted off at the edge of Walnut Lake after destroying a garage near the water's edge. The only death occurred in a car that was thrown from the business intersection landing upside down. Most injuries were in the intersection where a dozen cars were lifted into the air and where large amounts of debris were thrown through windows of busy restaurants and gas stations."10 51

9 April 3, 1974: Five tornadoes in Hillsdale, Jackson, Lenawee, and Monroe Counties These tornadoes, in the southeastern tier of Michigan Counties, were at the northern end of the United States' worst tornado outbreak (Super Outbreak)' which stretched southward as far as northern Alabama. The 148 tornadoes in the 24-hour period from midday April 3 to midday April 4 included the Xenia, Ohio tornado, considered by some to be the strongest tornado ever experienced. Th ree of the five tornadoes in Michigan were reported in Hillsdale County, where the two deaths and thirty-eight of the fo rty-four injuries occurred. These excerpts are from the National Oceanic and Atmospheric Administration storm reports : 11 " 25 homes, 15 mobile homes destroyed. 100 others damaged. Both deaths and 27 of the injuries in mobile homes." "Houses and barn demolished near Prattville. Barn damaged and three mobile homes destroyed near Hudson. One mobile home exploded. Two occupants injured" " House damaged, outbuildings destroyed, barned twisted off foundation, and tractors swirled in air in Lenawee County." April2, 1977: Six tornadoes, one each in Clinton, Eaton, Ingham, Kalamazoo, Livingston, and Shiawassee Counties Forty-four of the sixty-two injured were in Eaton County and ten in Kalamazoo County. The Eaton County tornado " Was a huge tornado averaging al most three quarters of a mile wide. It cut an eighteen mile path thru the hart (sic) of Eaton Co. destroying 21 homes, 10 mobile homes, 24 barns, 28 outbuildings and 21 vehicles. 23 cattle and horses were also lost. The only fatality occurred when the tornado crossed 1-69 sweeping two motor homes and a pickup truck off the roadway. The pickup was thrown 50 feet and landed upside down in a pile of falling trees crushing a 5 year old boy inside."12 July 4, 1969: Four tornadoes, one each in Hillsdale, Jackson, Washtenaw, and Wayne Counties The tornado in Wayne County injured 50, largest number by a single tornado in that county in the 35-year period. There was extensive coverage in the Detroit Free Press, from which the following were taken: 13 " Violent thunderstorms laced with tornadoes washed torrential rains across Michigan and into Ohio late Friday and early Saturday. "The six-hour storm left an estimated 40 persons injured and pockets of devastation as twisters hopscotched throughout the state' s southeast corner. " There were no deaths in Mich i gan directly attri buted to the storm. But scores of persons were left homeless and property damage was certain to run at least into the hundreds of thousands of dollars. " Twisters touched down in Flat Rock, Augusta Township in Washtenaw County, Adrian, on the outskirts of Jackson and in rural areas of Milan and Hillsdale. "Most of the local storms injuries occurred in Flat Rock, in western Wayne County, where one house was leveled and four others seriously damaged. April 21, 1967: Ten tornadoes in Allegan, Barry, Cass, Clinton, Eaton, Ingham, Ionia, Kent, and Muskegon Counties Half of these Southwest Michigan tornadoes injured people, the worst of those five being one in Kent County that injured 32. The National Oceanic and Atmospheric Administration report said, 52

10 " Funnel moved east-northeastward, lifting at times, with possibly two funnels at other times based on observation of variable width of storm damage path, 300 to 600 yards. Four injured were hospitalized. Sixty-five structures completely destroyed, 60 suffered major damage, 375 suffered minor damage. Total estimated damage near 8 million."14 From the foregoing accounts and additional analyses of Michigan's recent tornado history, it has been determined that the risk of injury or death by tornado in Michigan is quite small. As shown, a very large proportion of all deaths and injuries in the 35-year period from 1950 through 1984 occurred on just twelve days. On two of those days, tornadoes moved through densely populated areas which had no advance warning. It is true that many of Michigan's tornadoes occur in the densely populated southern third of the Lower Peninsula, but when tornado death toll is considered in relation to state population, Michigan ranks eleventh. In terms of deaths per 100,000 residents, Michigan has had 2.6 compared w ith 15.1 in Mississippi, 7.8 in Oklahoma, 7.7 in Arkansas, 7.5 in Kansas, 4.0 in Indiana, 1.6 in Wisconsin, 1.4 in Ohio, and 1.3 in illinois. The average annual frequency of tornadoes within 10,000-square-mile circles is 3-4 in the southern Lower Peninsula and 1-2 in the rest of the state whereas in the core of 'Tornado Alley' it is 5_9. 15 Thus, even in the populous counties of Michigan, the long-term probability of tornadoes is, at most, moderate. Finally, there appears to be a basis for optimism regarding tornado risk in Michigan in the tremendous difference between the numbers killed and injured in the chronological first six and the second six catastrophic outbreaks (Table 3). It is concluded that this can be attributed, at least partly, to improved and more widespread warning systems as well as increased public awareness of the tornado threat. In the next ten years, the National Weather Service will have a network of advanced radars that " will make possible a warning lead time of 20 minutes or more-ample time to ensure that lives and property... will be at substantially less risk than ever before from dangerous storms."16 REFERENCES 1. A computer listing of all Michigan tornadoes from 1950 through 1984 was provided by the National Weather Service. National Severe Storms Forecast Center. Kansas City. MO. These data were reorganized and processed by the authors on microcomputers at Eastern Michigan University. 2. Slorm Dala, December NOAA. Environmental Data Service, Asheville, NC 3. Slorm Dala, December NOAA, Environmental Data Service. Asheville. NC- 'Definition of Fujita Scale', p Brooks. E. M.. "Tornado Tragedies of 1953." Wea lherwise, August Hardy. W. E.. "Tornadoes During 1965." Wealherwise, February Slorm 0818, April 1965, U.S. Dept. of Commerce. Weather Bureau, Asheville. NC 7. Delroil Free Press, April Delroil Free Pre$s, May Slorm D81a, May 1980, NOAA, Environmental Data Service, Asheville, NC 10. Slorm Da18, June 1976, Late Reports, NOAA, Environmental Data Service. Asheville. NC 11. Slorm Dala, April 1974, NOAA, Environmental Data Service, Asheville. NC 12. Slorm Dala, April 1977, NOAA, Environmental Data Service, Asheville, NC 13. Delroil Free Press, July Slorm Dala, April 1967, U.S. Dept. of Commerce, Environmental Science Services Administration. Environmental Data Services, Asheville, NC 15. Ostby, F. P., Jr. and L. F. Wilson. "Tornado!." Wealherwise, Vol. 84, No.1, February Milner, S., "NEXRAD- The Coming Revolution in Radar Storm Detection and Warning," Wealherwise, Vol. 39, No. 2, April