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Great Plains Quarterly Great Plains Studies, Center for

Fall 1983

Across The 49th Thunderstorms In The Northern Great Plains

Alec H. Paul University of Regina

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Paul, Alec H., "Across The 49th Thunderstorms In The Northern Great Plains" (1983). Great Plains Quarterly. 1696. https://digitalcommons.unl.edu/greatplainsquarterly/1696

This Article is brought to you for free and open access by the Great Plains Studies, Center for at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Great Plains Quarterly by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. ACROSS THE 49TH THUNDERSTORMS IN THE NORTHERN GREAT PLAINS

ALECH. PAUL

Hail, lightning, flash floods, erosion, severe the relatively sparsely populated north, most of gusty winds, and tornadoes produce multi­ the detailed research into the thunderstorms of million-dollar losses to the economy of the the plains has been done in a few limited re­ northern plains each summer. Research into gions, particularly in Oklahoma, Kansas, south­ these meteorological phenomena has been ern Illinois, and eastern Colorado. This article fragmented by the presence of political boun­ treats the thunderstorm hazard in the more daries in the Great Plains, especially the 49th northerly portion of the Great Plains, as shown parallel, which separates the United States and in Figure 1. As it is clear from my data that the Canada. Perceptions of and responses to the thunderstorm problem is common to both the thunderstorm hazard still differ north and American and Canadian sections of the northern south of the border. Tornadoes, for example, plains, I examine the sometimes different re­ have only recently appeared in the weather sponses to storm problems on either side of the forecasts for the Canadian prairies, and such 49th parallel. Finally, I show that a more uni­ responses to summer storms as weather modifi­ fied approach to the thunderstorm problem in cation experiments and hail insurance coverage the northern plains is emerging, as researchers have been made in different ways in the two on both sides of the international boundary countries. marshall their resources to produce a more Because the most spectacular manifestation effective system for monitoring and under­ of thunderstorm weather, the tornado, occurs standing the characteristics of storms and their most often in the southern and central plains, impact on the land and people of the plains. and because storms have traditionally been

considered more severe in these areas than in THE SCALE OF THUNDERSTORM HAZARD

Tornadoes and devastating hail and lightning Alec H. Paul is professor of geography at the University of Regina. He has published several storms vie with drought as the chief compo­ articles on hail and thunderstorms on the Cana­ nents of the "climatic image" of the southern dian prairies and has served as chief editor of and central Great Plains. Farther north, bliz­ Prairie Forum. zards and drought receive the most attention; 195 196 GREAT PLAINS QUARTERLY, FALL 1983

Montana and Wyoming. Changnon found that over the decade from 1960 to 1969, North Of Dakota led all other states in dollar losses to hail.3 Hail-insurance loss costs on the Cana­ ...... , dian prairies are similar to those immediately '. south of the 49th parallel. In view of the large \ \ area of cropland, it is not surprising that dollar losses are high. In Saskatchewan alone, crop­ . hail damage in the 1960s has been estimated at \ about one-seventh of the loss in the entire \ MONTANA 4 0', United States for the same period. Thus hail '- \ 0- • I remains an important hazard throughout the \ \ northern plains and into the Canadian prairies. \. WYOMING , Tornadoes are an occasional, unwelcome '-- -, 'I adjunct to severe thunderstorms. It has often been shown that tornadoes decrease in fre­ quency northward and northwestward from the FIG. 1. The study area, with existing and former hail-suppression projects. The larger "Tornado Alley" of the south-central Great circles indicate statewide programs financed by Plains.5 Gordon McKay and A. B. Lowe sug­ state funds; other symbols indicate projects of gested in 1960 that this decrease continues smaller scale. north of the 49th, with tornado frequency in western Canada at a maximum in southeastern Saskatchewan and southwestern Manitoba and thunderstorm weather has seemed less impor­ decreasing northwestward and northeastward.6 tant. Only recently has a more accurate assess­ Recent attempts at documenting tornado ment of the damage done by northern plains touchdowns on the Canadian prairies suggest thunderstorms begun to emerge. In Iowa, Steve that the frequency is higher than expected, and Eshelman and John Stanford investigated the probably not significantly lower than in the 1974 thunderstorm season and found a vast northern tier of Great Plains states.7 These and largely unsuspected amount of damage.1 states are regarded as an outlying extension of Recent work on the Canadian prairies has pro­ Tornado Alley, with a local maximum of duced similar results.2 This research suggests tornado frequency in eastern Montana and that the decline in thunderstorm severity from western North Dakota.8 The U.S. Weather Kansas and Colorado northward may be less Service has developed official watches and than is usually perceived. One reason for this warnings for tornadoes. By contrast, the word perception is that population density, an im­ tornado began to appear in weather forecasts portant factor in accumulated storm damages, for the Canadian prairies only in the late 1970s, is relatively low in the northern plains. despite the fact that the largest death toll­ Crop losses caused by hail in the northern thirty persons-for a single tornado anywhere in plains states and on the Canadian prairies are the northern plains occurred in Regina, Sas­ very high. This region is the spring wheat belt, katchewan, in 1912. Canadian popular opinion where the hail season and the growing season still tends to relegate tornadoes to the United closely coincide. Stanley Changnon's study of States. hail losses in the United States showed that Thunderstorm-produced floods have their loss costs for crop-hail insurance (the ratio of most dramatic consequences in mountainous or losses paid to the amount of risk underwritten) at least hilly terrain, where they cause devas­ in the northern plains states are high, with some tating flash floods in small drainage basins. The of the largest values being found in eastern Rapid City disaster of June 1972 and the Big ACROSS THE 49TH 197

Thompson Canyon flood of July 1976 are This brief overview of the thunderstorm cases in point.9 However, heavy thunderstorm hazard in the northern plains states and the rains produce floods with occasional fatalities Canadian prairies lacks a detailed dollar assess­ and great damage to property, crops, and farm­ ment. Preliminary work suggests, however, that land throughout the flatter sections of the total thunderstorm losses in the region of this North American interior. These are "million­ study amount to millions of dollars annually, dollar rains," in the negative sense (table 1). a sum large enough to stimulate increasing ef­ Like hail and tornadoes, they occur on both forts to reduce and adjust to thunderstorm sides of the 49th parallel. losses.12 Other thunderstorm hazards are lightning and high winds. The compiled data on their RESPONSE TO THE HAIL HAZARD effects in the northern plains are scanty at best, but local newspapers appear to be a promising The general behavior of severe hailstorms in source, according to studies done by Dan Blair the North American interior appears fairly in southern Saskatchewan.10 Thunderstorm consistent. Most storms produce long, narrow winds and lightning strikes present major prob­ tracks of hail across the countryside ("hail­ lems for power and telephone companies. Total swaths"), although large convective complexes losses due to wind and lightning require much producing hail "areas" rather than clear-cut research to compile; one of the few thorough swaths also occur. Hail is a significant hazard studies of lightning-produced power outages is in all parts of the region under study, and by Steve La Dochy, for Manitoba.ll Table 2 there are a variety of ways to cope with the illustrates some examples of lightning and problem. Insurance, for example, is available thunderstorm wind losses in the northern throughout the region, but premiums are so plains. high in some localities that many farmers

TABLE 1

EXAMPLES OF LOSSES FROM THUNDERSTORM RAINS

Estimated Losses Rainfall Location Date (Million $) (Inches)

Minneapolis-St. Paul area 30-31 August 1978 > 5 6 Rochester, Minnesota 5 July 1978 >50 6

Southeastern North Dakota 28-29 June 1975 >50 ~ 12 Deadwood, South Dakota 14 June 1976 6 Lethbridge, Alberta 22 August 1978 1 3 Regina, Saskatchewan 25June 1975 12 6 Winnipeg, Manitoba 20 May 1974 7 1

SOURCES; The information in this table was taken from Storm Data, a monthly publication of the U.S. National Oceanic and Atmospheric Administration, from insurance estimates (revised rather than initial) reported in news­ papers, and from K. A. Fluto and P. B. Lemieux, The 1974 Victoria Day Rainstorm in Winnipeg and Vicinity, Canada Department of Transport, Meteorological Branch, Tech. Mem. 824 (Toronto, 1975). 198 GREAT PLAINS QUARTERLY, FALL 1983

TABLE 2

LIGHTNING AND THUNDERSTORM WIND LOSSES IN THE STUDY REGION

Location Date Cause of loss Loss

Mankato, Minnesota 23 July 1977 Lightning Elks Club fIre: $300,000 Carbon, Montana 2 July 1978 Lightning 1 death Gettysburg, South Dakota 29 July 1979 Lightning 1 death Fulda, Saskatchewan 23 June 1980 Lightning 1 death, 1 severe injury West-central Saskatchewan 3 June 1976 Storm winds 1 death; $4 million Fort Totten, North Dakota 6 July 1977 Storm winds Trees uprooted, an electrical switching station and a center- pivot irrigation system damaged Wheatland, Wyoming 24 June 1978 Storm winds Roofs removed, municipal water tower damaged, trees uprooted

SOURCES: Storm Data and newspapers. choose not to insure their crops against hail provinces. Saskatchewan's municipal hail pro­ damage.13 Hail suppression, a form of deliber­ gram, for instance, was established in 1913 ate modifIcation of weather, has been attempted and continues to the present time.1S in some instances (fIg. 1). Premiums for hail insurance in the study Insurance. Hail insurance in the northern region are set for each township, the six-mile­ Great Plains was fIrst sold in 1889 in North square unit of the initial land survey. It is thus Dakota. The earliest hail-insurance companies possible-admittedly only in certain extreme were too localized and were gradually replaced cases-for a farmer to pay almost twice as much by or combined into bigger companies that for hail insurance, on the same amount of lia­ spread their risk over much larger geographical bility for the same crop, as his neighbor across areas. The importance of the hail hazard in the the road. Such an anomaly arises from the northern plains is indicated by the presence of insurance companies' practice of deriving pre­ hail-insurance operations run by states and mium rates in most cases from their experience provinces. North Dakota was the fIrst state to of hail losses in individual townships, rather have a hail-insurance program, in 1911; Mon­ than grouping townships into larger areal units tana and Nebraska followed in 1917 and 1918 for the purpose of setting rates. Since two respectively, and South Dakota in 1919.14 Of companies often have different loss experiences the three such state hail-insurance programs even within a single township, they may set remaining in operation today, two are in the different premium rates for hail coverage in northern plains, in Montana and North Dakota. that township. Rates are more consistent south (The other is in Colorado.) On the Canadian of the 49th, because most United States com­ prairies, the government of the North-West panies writing hail insurance belong to the Crop Territories instituted a crop-hail insurance Hail Insurance Actuarial Association, which scheme in 1902, followed after 1905 by prov­ standardizes the premiums charged in a par­ ince-sponsored schemes in the three prairie ticular township by its members.16 ACROSS THE 49TH 199

Insurance is not a completely satisfactory Alberta Hail Studies. This project has greatly response to the hail hazard. In high-premium increased our understanding of hailstorms, townships, many farmers are reluctant to pay and in the 1970s it evolved into an operational for insurance, and they look for other solutions and research-oriented hail-suppression program. to the hail problem. 17 The Saskatchewan Hail Research Project Hail suppression and hail research. Many (SHARP) ascertained that the hailstorms of people believe that hail can be suppressed by southern Saskatchewan are only slightly less cloud seeding, a form of weather modification severe than the notorious storms of the high technology that is controversial and statistical­ plains, as studied in Colorado and Alberta.19 ly unproven. The theory is that the "seeding" SHARP also surveyed the opinions of local of large numbers of tiny particles of silver farmers on the relative importance of certain iodide or another suitable substance into the weather hazards to agriculture in the region hailstorm cloud will result in larger numbers of and found that drought was perceived to be a much smaller hailstones than would occur much greater threat than hail.20 In fact, crop­ naturally. It is postulated that the hailstones insurance payments in Saskatchewan for hail will largely or even completely melt during have been larger than those for drought in most their fall to the ground and that crop-hail years. The farmers' perception reflects the damage will therefore be reduced. catastrophic effect that drought may have in a The willingness to utilize and support hail limited number of years, and it may partially suppression has been much greater in the states explain why farmers in the region displayed than on the Canadian prairies, where it has been little awareness of the existence of cloud­ tried only in central Alberta (fig. 1). Early seeding programs elsewhere that aim to sup­ attempts to evaluate these suppression projects press hail. scientifically were inadequate. Without any On the American side of the study region, a sound proof of their claimed success, the public project based at Rapid City, South Dakota, has support on which they depended faded away contributed much basic knowledge on the after a number of years. Barbara Farhar has characteristics of hailstorms.21 Studies of the described the situation in South Dakota, where hail climatology of the northern plains, how­ the state government established a statewide ever, have been restricted to general work such program of weather modification by cloud as Glenn Stout and Stanley Changnon's Clima­ seeding for both rainfall enhancement and hail tography of Hail in the Central United States. 22 suppression in 1972, and then terminated it in The one major exception is the work of E. M. 1976 in the face of public controversy.18 Frisby, especially in eastern South Dakota.23 An important outcome of the pioneer hail­ The most significant hail research and suppres­ suppression programs of the 1950s was the sion effort on the American Great Plains has institution of basic research into the character­ been further south, in eastern Colorado. It istics of the region's hailstorms. The government culminated in the U.S. National Hail Research of Alberta, for instance, received a request Experiment of 1972_76.24 from a number of central Alberta farmers Hail forecasting. Although accurate short­ plagued by severe hail in the early 1950s range forecasting of hailstorms cannot help for financial support for a hail-suppression reduce damage to crops, it can decrease other program. The provincial government responded losses to some extent. In some cases automo­ that it could not finance a program whose biles and farm machinery can be moved into benefits had not been scientifically proven. garages, carports, or sheds, planes on the In 1956, however, Alberta joined with the ground can be parked in hangars, and planes in Canadian federal government and the meteo­ flight can be diverted around the storm. Live­ rology department of McGill University to stock, people, and poultry may be moved establish a basic research project known as indoors. But these measures are not always 200 GREAT PLAINS QUARTERLY, FALL 1983 feasible, and in any case much of the property that damaging storms may arrive from any 0 0 loss in hailstorms is damage to windows, siding, point of the compass between 180 and 360 • 28 and roofs. In fact, several studies in the Great Plains have The forecasting of hailstorms involves two ascertained that farmers do not obtain non­ steps. The fIrst is to identify general meteoro­ contiguous landholdings for the purpose of logical situations that will produce hailstorms reducing hail 10ss.29 The common occurrence at unknown locations within the forecast of "fragmented" farms in the region is a result region. The second involves the actual tracking of the farmers' need to expand their scale of of severe thunderstorms by radar and the antic­ operations. They have thus purchased or rented ipation of their specifIc paths. In practice, additional land wherever it was available within step two is incorporated into public forecasts a reasonable distance of the home quarter.30 only if there are indications that a tornado may accompany the storm; furthermore, not all RESPONSE TO THE TORNADO HAZARD areas are scanned by weather radar. Since hail forecasting results in only small reductions in Although the threat of tornadoes in the ground-level damages, it has been important northern plains is similar north and south of the primarily for aviation and the hail-suppression 49th parallel, the responses of the two coun­ and hail-research projects. Hail forecasting for tries have differed markedly. Canadians have central Alberta and western South Dakota has tended to denigrate the tornado hazard on the received this specialized attention.25 In other Canadian prairies until very recently, while in parts of the study region, the practice of fore­ the northern plains states, the danger of tor­ casting hail is often hindered by lack of feed­ nadoes has been considered small but signifi­ back. The forecaster may not hear of hail in cant enough to merit scientific research. his region unless it falls at one of the widely The northern plains states. Table 3 sum­ dispersed fIrst-order weather stations. In the marizes the damage caused by some major absence of information, he does not know tornadoes in the northern plains states. Meteo­ whether his forecasts regarding the chance of rologists have estimated that tornadoes have hail have been correct or not.26 been relatively infrequent in the region, but it Breeding hail-resistant crop varieties. Some is possible that the reporting of tornadoes is work has been done in the northern plains to less complete in these states than in Tornado develop hail-resistant crops and to determine Alley. Eshelman and Stanford, for instance, how hail inflicts damage on plants.27 These conducted a detailed survey of severe local efforts have not led to significant improve­ storms in Iowa for the summer of 1974.31 ments; in general, crop resistance to other They identified three times as many verified hazards, such as drought or insects, has been tornado touchdowns (eighty-one) as were considered more important. reported in the official listing of the National Noncontiguous farmland patterns. In most Severe Storms Forecast Center (twenty-seven). storms hail damage is confIned to long, narrow Serious study of tornadoes in the northern strips, or "damaging hail-swaths." Thus it has plains states dates from the 1950s. U.S. govern­ often been suggested that a farmer might re­ ment weather offices in the region have released duce his loss to hail damage in a given year by many tornado watches and warnings, using the working two or more parcels of land several forecasting techniques developed farther south. miles apart. Another suggestion is that the hold­ Specialized climatological studies of tornadoes ings should be in locations such that the line in the area have been undertaken by scholars connecting them is perpendicular to the pre­ such as Richard Skaggs, for Minnesota.32 vailing direction of hailstorm movement. Public awareness of the tornado danger has in­ This is a fallacious argument, because maps of creased, and in some parts of the region tornado­ hailstorm tracks in the northern plains show preparedness plans have been put into place and ACROSS THE 49TH 201

TABLE 3

SOME TORNADOES IN THE NORTHERN PLAINS STATES

Location Date Deaths Injuries

Fargo, North Dakota 20 June 1957 10 100 Tracy, Minnesota 13 June 1968 9 Elgin, North Dakota 4 July 1978 5 35 Gary-Fosston, Minnesota 5 July 1978 4 38 Cheyenne, Wyoming 16 July 1979 1 40

SOURCE: Storm Data.

emergency organizations are thoroughly drilled per unit of area affected. Public awareness of on appropriate measures in severe storms.33 the hazard is strongly influenced in the United One basic difficulty for the researcher lies States by the extensive publicity they receive in the contrast in population density between in the national news media. the dairy belt of Minnesota and the wheat­ The Canadian prairies. The situation has and rangeland of the Dakotas and the high been noticeably different in Canada. The word plains. Until the 1970s the frequency of torna­ tornado almost never appeared in the weather does in the high plains of Colorado, Wyoming, forecasts for the region until the late 1970s. and Montana was thought to be very low.34 Yet tornadoes do occur on the prairies, and in In the late 1970s and early 1980s, however, 1960 an important milestone was reached when this view has been revised. Some devastating A. B. Lowe and G. A. McKay published their tornadoes have occurred in the cities, and more study, "The Tornadoes of Western Canada," tornadoes are being reported in formerly empty for the Canadian government's Meteorological areas where the population has grown because Branch, the predecessor of today's Atmospheric of increased tourism and the exploitation of Environment Service (AES).37 The study in­ mineral resources.35 Eastern Montana and volved a review of the front pages of local Wyoming, long regarded as areas of low tornado newspapers, local histories, and other sources, incidence, are being reevaluated. For example, followed by telephone calls, letters, and inter­ J. T. Schaefer et al. have identified a locale in views to verify the occurrences. Lowe and eastern Montana and western North Dakota McKay documented about one hundred deaths with a tornado frequency above the regional caused by tornadoes. average.36 Despite the publication of this dramatic A view is therefore emerging of the northern report, AES forecasters in the Canadian prairies plains states as an extension of the major began to issue tornado watches only in the mid- tornado hazard zone of the central and south­ 1970s, after a number of tornadoes occurred ern plains. All forecast offices of the region give in Manitoba and Saskatchewan. Budget cuts serious consideration to the chance of torna­ suffered by the AES led in 1979 to the consoli­ does in spring and summer. Tornadoes are dation of all forecasting for Manitoba and known to be the most dangerous storms in Saskatchewan into the Winnipeg office. Because terms of the number of deaths and injuries Lowe and McKay had concluded that tornadoes 202 GREAT PLAINS QUARTERLY, FALL 1983 on the Canadian prairies are most frequent in with the need to establish scientific credibility southern Manitoba, the Winnipeg office had for hail suppression, led to the emergence of a maintained a listing of Manitoba tornadoes more holistic approach in the 1970s, especially from 1960 on and thus possessed a more in the United States, where both state and fed­ realistic appraisal of their frequency than the eral governments became involved in weather Regina Weather Office had. The Regina office modification operations and research. Hail­ had begun to assess tornado occurrence in storms often cross state lines, and seeding a southeastern Saskatchewan, but after 1979, storm in one state may affect its behavior in the such efforts expanded in Winnipeg. Using local next.40 Major hail research projects, such as the newspapers as his source, Dan E. Blair has com­ National Hail Research Experiment in north­ piled a more exhaustive listing of Saskatchewan eastern Colorado, have thus received federal tornadoes from 1971 to 1980.38 A study by funding in recognition that Washington has a Keith Hage, for Alberta, appears to be the most responsibility where the interests of individual painstaking work on tornadoes on the Canadian states in a weather-modification wrangle may .. . 39 pralnes In recent years. conflict. Yet the vexing question of the effi­ When all this recent work for the Canadian cacy of hail suppression is still not answered. prairies is brought together, a long-overdue Hail insurance also has become more stan­ reassessment of the tornado hazard in the dardized in the United States. The Crop-Hail region will be possible. Enough tornadoes have Insurance Actuarial Association not only sets been documented from the 1960s and 1970s rates for its member companies within a given to demonstrate that a threat exists and that the township, but also has such a vast amount of Severe Weather Watch program, now imple­ accumulated experience that the excessively mented across the prairies, is justified. high premiums formerly charged in some regions are gradually being reduced. A MORE UNIFIED ApPROACH Research on severe local storms is now being carried out in the United States in parts of the Gradually a more unified approach to the northern plains where it has not been con­ problems of living with summer storms in the ducted before. The High Plains Experiment northern plains is emerging north and south of (HIP LEX) in Montana and the increased study the border. On the American side, the avail­ of tornadoes in the high plains are examples ability of tornado-forecast information for the of this activity.41 entire United States since 1953 (from what is This more unified approach to the thunder­ now the National Severe Storms Forecast Center storm problem is now spreading across the in Kansas City) has played an important role in 49th parallel to the Canadian prairies. The this development. In effect, the forecasterin the skeletal record of thunderstorm outbreaks, so northern plains states was backed up after this scant in the past (especially of storms that date by an increasingly sophisticated and spe­ straddled provincial boundaries or "ended" or cialized arm of the National Weather Service. "started" at the 49th), is being fleshed out. The more systematic reporting of tornadoes in The severe thunderstorm weather across the the U.S. northern interior, coupled with the southern prairies in the final week of June 1975 forecast effort, has spread an awareness and provides an excellent illustration (fig. 2). It preparedness that would not have arisen with­ covered a large area and was part of an out­ out the nationally supported program. break that seriously affected the northern The same point applies to the hail problem. plains states as well. This outbreak effectively The small hail-suppression projects of the 1950s buried the notion that tornado-producing and 1960s still operate in some instances. How­ thunderstorms on the Canadian prairies are ever, the important question of the so-called freak, isolated events. Heavy damage occurred downwind effects of cloud seeding, together in many locations on both sides of the border. ACROSS THE 49TH 203

~ Severe storm track seeding actlvltles of the Alberta Hail Project, L-Lightning death or major damage and the federal AES is charged with monitoring W-Thunderstorm wind damage ", F -Thunderstorm flooding all weather modification programs in the coun­ H-Local severe hail try.43 Prairie forecasters are fully aware of '" T-Tornado weather conditions developing on both sides of the border and pay special attention to the U.S. forecasts for the northern plains states, where the information on upper-air conditions is much better than the data for the prairies. Research on severe local storms in the northern plains of the North American interior is showing signs of greater coordination, both \, w within and between the United States and Canada. Americans and Canadians alike can make valuable contributions to a greater FIG, 2. Severe thunderstorm weather, 24-30 understanding of and more effective response June 1975. to the problem of storm hazards. The emerging cooperation across the 49th parallel should Studies of such conditions by AES and other continue to build on the foundation that has researchers have greatly aided prairie fore­ been laid. casters. A Severe Weather Watch program is now in effect on the prairies. Weather radar was NOTES introduced in southern Saskatchewan in 1981, a partial supplement to systems in use at Winni­ 1. Steve Eshelman and John L. Stanford, peg, Calgary, Edmonton, and Red Deer. Inter­ "Tornadoes, Funnel Clouds and Thunderstorm est in hail suppression by cloud seeding, how­ Damage in Iowa during 1974," Iowa State Jour­ ever, has not spread beyond central Alberta. nal of Research 51 (1977): 327-61. Canadians have had little knowledge of the 2. See, for example, Dan E. Blair, "The North Dakota State Weather Modification Thunderstorm Hazard in Saskatchewan" (M.S. Program, which certainly had a potential influ­ thesis, University of Regina, 1983); Steve La Dochy, "Lightning Hazard in Manitoba: A ence on severe storms tracking north or north­ Review" (Paper delivered at the annual meeting east into Saskatchewan or Manitoba. Commer­ of the Canadian Association of Geographers, cial hail-insurance companies on the prairies Ottawa, 1982); Alec H. Paul, "The Thunder­ still charge rates that may differ from company storm Hazard on the Canadian Prairies," Ceo­ to company for the same township. forum 13 (1982): 275-88. Research in Canada is advancing. Severe 3. Stanley A. Changnon, Jr., "Examples of weather outbreaks have been tracked from one Economic Losses from Hail in the United province to another and have on occasion been States," Journal of Applied Meteorology 11 linked with simultaneous severe weather south (1972): 1128-37. of the border.42 For example, thunderstorms 4. Alec H. Paul, "Hailstorms in Southern originating in south-central Saskatchewan on Saskatchewan," Journal of Applied Meteorol­ the night of 19-20 June 1974 were tracked as ogy 19, no. 3 (1980): 305-14. 5. Most recently by D. L. Kelly, J. T. far southeast as Indiana over the next two days. Schaefer, R. P. McNulty, C. A. Doswell III, Because experience tracking such far-reaching and R. F. Abbey, Jr., "An Augmented Tornado storms has shown that severe local weather may Climatology," Monthly Weather Review 106, travel great distances, the provincial research no.8 (1978): 1172-83. council of Saskatchewan has expressed concern 6. Gordon A. McKay and A. B. Lowe, "The over possible downwind effects from the cloud- Tornado in Western Canada," Bulletin of the 204 GREAT PLAINS QUARTERLY, FALL 1983

American Meteorologial Society 41, no. 1 17. Over 40 percent of farmers in the (1960): 1-8. Calgary-Red Deer area of Alberta had pur­ 7. Searches of such sources as local news­ chased no hail or general crop insurance in the papers in all three prairie provinces in recent years from 1964 to 1973; E. P. Lozowski, "An years have revealed numerous tornadoes that Alberta Weather Modification Survey," Albertan were not previously known to practicing Geographer 11 (1975): 1-11. meteorologists in the region. Very few of these 18. Barbara Farhar, "People's Attitudes and studies have been published; one exception is Concerns," in Hail Suppression Impacts and the report by T. B. Shannon, Manitoba Tor­ Issues, ed. by Stanley A. Changnon, Jr., et al. nadoes, 1960-73, Canada, Atmospheric En­ (Urbana: Illinois State Water Survey, 1977), pp. vironment Service, Meteorological Applications 123-29. Branch, Project Report no. 29 (Toronto, 1976). 19. Paul, "Hailstorms in Southern Saskatch­ 8. J. T. Schaefer, D. L. Kelly, and R. F. ewan," p. 313. Abbey, Jr., "Tornado Track Characteristics 20. Raymond E. Clyde, "A Study of Sas­ and Hazard Probabilities," in Wind Engineering, katchewan Farmers' Perceptions of Hail, ed. by J. E. Cermak (Oxford and New York: Drought, and Flood as Hazards to Agriculture" Pergamon Press, 1980): 95-109. Tornado (M.A. thesis, University of Regina, 1981). Alley is a name often used for the area that 21. See, for example, A. S. Dennis, C. A. extends from the Texas Panhandle to the Schock, A. Koscielski, and D. J. Musil, Report central Mississippi valley and has the highest on Hailstorm Models Project, Institute of At­ tornado frequencies in the United States. mospheric Sciences, South Dakota School of 9. Robert A. Maddox, Lee R. Hoxit, Mines and Technology (Rapid City, 1969); Charles F. Chappell, and Fernando Caracena, A. S. Dennis, C. A. Schock, and A. Koscielski, "Comparison of Meteorological Aspects of the "Characteristics of Hailstorms of Western South Big Thompson and Rapid City Flash Floods," Dakota," Journal of Applied· Meteorology 9 Monthly Weather Review 106 (1978): 375-89. (1970): 127-35. 10. Blair, "Thunderstorm Hazard in Sas­ 22. Glenn E. Stout and Stanley A. Chang­ katchewan." non, Jr., Climatography of Hail in the Central 11. La Dochy, "Lightning Hazard in Mani­ United States, Crop-Hail Insurance Actuarial toba." Association, Research Report no. 38 (Chicago, 12. In Saskatchewan alone, annual thunder­ 1968). storm losses average $130 million (in current 23. E. M. Frisby, "A Study of Hailstorms of dollars), at a conservative estimate; Alec H. Paul the Upper Great Plains of the North American and Dan E. Blair, "Thunderstorm Hazard in Continent," Weatherwise 17, no. 2 (1964): Southern Saskatchewan" (Paper delivered at 68-75; idem, "Relationship of Ground Hail the annual meeting of the Association of Amer­ Damage Patterns to Features of the Synoptic ican Geographers, Denver, 1983). Map in the Upper Great Plains of the United 13. See, for example, A. L. Rydant, "Ad­ States," Journal of Applied Meteorology 1 justments to Natural Hazards: Factors Affect­ (1962): 348-52; idem, "Hailstorms of the Upper ing the Adoption of Crop-Hail Insurance," Great Plains of the United States," Journal of Professional Geographer 31, no. 3 (1979): Applied Meteorology 2 (1963): 759-66. 312-20. 24. Charles A. Knight, G. Brant Foote, and 14. Leon B. Perkinson, Crop-Hail Insurance Peter W. Summers, "Physical Research and in the United States, U.S. Department of Agri­ General Conclusions from the National Hail culture, Economic Research Service Report Research Experiment," in Preprints, Sixth Con­ ERS-249 (Washington, D.C., 1965). ference on Planned and Inadvertent Weather 15. E. G. Hingley, Municipal Hail Insurance: Modification (Boston: American Meteorological A History of the Saskatchewan Municipal Hail Society, 1977), pp. 162-65; G. O. Linkletter Insurance Association, 2d ed., rev. (Regina, andJ. A. Warburton, "An Assessment ofNHRE 1967). Hail Suppression Seeding Technology Based on 16. Changnon, "Losses from Hail in the Silver Analysis," Journal of Applied Meteorol­ United States." ogy 16 (1977): 1332-48. ACROSS THE 49TH 205

25. Richmond W. Longley and C. E. Thomp­ 34. A. H. Auer, "Tornadoes in Northeast­ son, "A Study of the Causes of Hail," Journal ern Colorado, 1965," Monthly Weather Review of Applied Meteorology 4, no. 1 (1965): 69-82. 95 (1967): 32-34. 26. For example, a severe hailstorm on 17 35. Charles A. Doswell III, "Synoptic-Scale August 1974 in southern Saskatchewan went Environments Associated with High Plains totally undetected by the official weather Severe Thunderstorms," Bulletin of the Ameri­ records, even missing all the Atmospheric can Meteorological Society 61, no. 11 (1980): Environment Service cooperative weather ob­ 1388-1400. servers; Alec H. Paul, "Some Unofficial Obser­ 36. Schaefer, Kelly, and Abbey, "Tornado vations of Summer Storms in Southern Sas­ Track Characteristics," p. 105. katchewan, 1973-77," in Essays on Meteorol­ 37. A. B. Lowe and G. A. McKay, The ogy and Climatology; In Honour of Richmond Tornadoes of Western Canada (Toronto: Cana­ W. Longley, ed. by K. D. Hage and E. R. da Department of Transport, Meteorological Reinelt (Edmonton: University of Alberta, Branch,1960). 1978), pp. 191-210. 38. Blair, "Thunderstorm Hazard in Sas­ 27. D. B. Knowles, The Effect of Hail katchewan. " Injury on Wheat and Other Grain Crops in 39. Keith Hage, University of Alberta, De­ Saskatchewan, University of Saskatchewan partment of Geography, personal communica­ Research Bulletin no. 102 (Saskatoon, 1941); tion. Lowe and McKay's pioneering work on M. M. Afanasiev, The Effect of SimuL:i.ted Hail prairie tornadoes is now being expanded by Injuries on Wheat, Montana Agricultural Ex­ several researchers. periment Station Bulletin no. 613 (Bozeman, 40. Ray J. Davis, "Trends in Weather 1967). Modification Legislation," Journal of Weather 28. See, for example, Frisby, "Hailstorms of Modification 6 (1974): 17-27. the Upper Great Plains," p. 72; Paul, "Hail­ 41. Melvin J. Schroeder and Gerard E. storms in Southern Saskatchewan," pp. 309- Klazura, "Computer Processing of Digital Radar 10; L. Wojtiw, Climatic Summaries of Hailfall Data Gathered During HIPLEX," Journal of in Central Alberta (1957-73), Alberta Re­ Applied Meteorology 17 (1978): 498-507; search, Atmospheric Sciences Report 75-1 David W. Reynolds, "Observations of Damaging (Edmonton, 1975), pp. 31-47. Hailstorms from Geosynchronous Satellite 29. Rydant, "Adjustments to Natural Haz­ Digital Data," Monthly Weather Review 108, ards," p. 318; Clyde, "Saskatchewan Farmers' no. 3 (1980): 337-48; Doswell, "High Plains Perceptions." Severe Thunderstorms." 30. E. J. Smith, Jr., "Fragmented Farms in 42. Alec H. Paul, "The Heavy Hail of the United States," Annals of the Association 23-24 July 1971 on the Western Prairies of American Geographers 65 (1975): 58-70. of Canada;' Weather 28 (1973): 463-71; 31. Eshelman and Stanford, "Tornadoes in idem, "Summer Storms in Southern Saskatch­ Iowa during 1974." ewan, 1973-77"; idem, "Prairie Tornadoes: 32. Richard H. Skaggs, "Aspects of Minne­ Research Note," Atmosphere-Ocean 19 (1981): sota Tornadoes," Minnesota Geographer 22, no. 66-70; Frisby, "Hailstorms of the Upper Great 2 (1970): 9-15. Plains." 33. See, for example, H. Michael Mogi! and 43. Canada, Twenty-Eighth Parliament, Third Herbert S. Groper, "NWS's Severe Local Storm Session, 19-20 Elizabeth II, 1970-71, The Warning and Disaster Preparedness Programs," Weather Modification Information Act. This Bulletin of the American Meteorological So­ was the first Canadian legislation relating to ciety 58, no. 4 (1977): 318-29. weather modification.