The Great Storm of 1975 (also known as the Super Bowl Blizzard, Minnesota's Storm of the Century, or the Tornado Outbreak of January, 1975) was an intense winter storm system that impacted a large portion of the Central and Southeast United States from January 9–12, 1975. A classic Panhandle hook, the mid-latitude cyclone produced an outbreak of 45 tornadoes in the Southeast U.S. resulting in 12 fatalities, while later dropping over 2 feet (61 cm) of snow and killing 58 people in the Midwest. This storm, which caused blizzard conditions, remains one of the worst blizzards to ever strike parts of the Midwest, as well as one of the largest January tornado outbreaks on record in the United States.
Meteorological synopsis
The storm originated over the Pacific Ocean and crashed into the Northwest Pacific coast with damaging gale-force winds on January 8, 1975.[1] By January 9 it had cleared the Rocky Mountains and began to redevelop and strengthen. At the same time, Arctic air was being drawn southward from Canada into the Great Plains, and large amounts of warm tropical air from the Gulf of Mexico were being pulled northward into much of the eastern U.S. The storm was a classic Panhandle Hook which moved from Colorado into Oklahoma before turning northward towards the Upper Midwest. It produced record low barometric pressure readings in the Midwest, with the pressure falling to an estimated 28.38 inHg (961 mb) just north of the Minnesota border in Canada.[2]
Tornado outbreak
Tornado summary event
An unusual feature of this outbreak was that daytime heating, typically a key ingredient in the formation of tornadoes, had very little impact on their development.[3][nb 1] Rather, as the storm system pulled out into the central plains, strong thunderstorms and tornadoes quickly began to form despite the late hours. The first two tornadoes touched down after 10:00 p.m. CST on January 9 in Oklahoma and Louisiana. From there the progression of the twisters shifted eastward through the overnight and early morning hours, setting the stage for what would turn out to be a record-setting day on January 10. Texas saw five tornadoes between 1:30 a.m.–3:30 a.m., one tornado touched down in Arkansas at 6:00 a.m., Louisiana saw seven tornadoes between 5:30 a.m.–8:00 a.m. (killing one person), Mississippi had five tornadoes between 8:15 a.m.–10:00 a.m. (killing nine), and Illinois and Indiana each experienced three lunch-hour tornadoes. The tornadic line of storms then shifted into Alabama (killing one) and Florida during the afternoon and evening hours.[5]
Mississippi and Alabama were the two states hardest hit by this outbreak. Alabama had the most twisters of any state with 13, but Mississippi saw the largest and deadliest tornado. An F4 tornado that tore through Pike, Lincoln, Lawrence, and Simpson Counties at 8:14 a.m. killed nine people and injured over 200, and severely damaged 38 blocks in the town of McComb. The 39 tornadoes on January 10 marked the most active tornadic day in January in U.S. history at that time.[6] The 52 tornadoes during January 1975 also set a U.S. record for the most tornadoes during that month. Both of these records were broken in January 1999.[7]
After a calm day on January 11, four more tornadoes touched down in Florida and Georgia on January 12, killing one person in Florida. By the time the outbreak ended it had produced 45 tornadoes, killed 12 people, injured 377 and caused $42 million in damages.[5]
Prior to 1990, there is a likely undercount of tornadoes, particularly E/F0–1, with reports of weaker tornadoes becoming more common as population increased. A sharp increase in the annual average E/F0–1 count by approximately 200 tornadoes was noted upon the implementation of NEXRADDoppler weather radar in 1990–1991.[8][nb 2] 1974 marked the first year where significant tornado (E/F2+) counts became homogenous with contemporary values, attributed to the consistent implementation of Fujita scale assessments.[12][nb 3] Numerous discrepancies on the details of tornadoes in this outbreak exist between sources. The total count of tornadoes and ratings differs from various agencies accordingly. The list below documents information from the most contemporary official sources alongside assessments from tornado historian Thomas P. Grazulis.
This tornado formed near the McAlester Army Ammunition Plant, then a naval ammunition depot, destroying five mobile homes. Assorted farmhouses and barns were damaged as well.[19]
This strong tornado developed near Bear Lake, unroofing a home and partly unroofing another. A few other homes and four outbuildings were destroyed nearby. Farther along, in the Alsatia–Transylvania area, the tornado badly damaged seven homes and destroyed a pair of trailers. Many outbuildings and barns were wrecked. A parsonage, church, and vegetation were extensively damaged. A final home was severely damaged near the end of the path. Six people were officially injured, but the actual total may have been three.[20][21]
A number of outbuildings were destroyed or damaged. A garage was moved 150 ft (50 yd), and a 2-mile-long (3.2 km) stretch of trees was felled. A pair of unanchored trailers were flipped and wrecked, and three homes were badly damaged.[23]
1 death – A trailer was destroyed near the touchdown point, resulting in the fatality. In Crowley, six trailers and seven homes were damaged. Eight people were injured.[20][21]
9 deaths – This long-tracked tornado, possibly a family, first destroyed a marina and seven structures, while uprooting or snapping at least 10,000 trees. Major damage affected 38 blocks in McComb and extended into Summit. In the McComb–Summit area, 88 homes, 80 apartment units, 60 businesses, two schools, two National Guard armories, and 200 automobiles were badly damaged or destroyed. The tornado injured five students, out of 325 who had taken shelter in a school. Just past McComb, 36 more homes were wrecked. Many homes, trailers, outbuildings, and barns were destroyed in rural areas as well. In the community of Camper, a trailer was destroyed, with its remains wrapped around a utility pole. 210 people were injured.[20][24]
20 large trees were uprooted. Piping and barns were destroyed, and six homes mildly damaged. One home sustained moderate damage, and a fallen tree damaged an automobile.[25]
A few empty chicken coops were wrecked and a number of barns partly so. Four homes incurred modest damage, and trees were felled as well. A mobile home was wrecked and a pair of others flipped.[25]
Half a dozen hangars lost roofing and siding, and a few airplanes inside were damaged. Outbuildings and a porch were damaged on a farmstead, and debris from one of the hangars was found in a tree on the property. A garage was leveled, crushing an automobile underneath, and a trailer was destroyed. Three homes sustained damage to parts of their roofs as well, one of which lost a whole section of roofing.[27]
1 death – In Pell City, the tornado destroyed 49 homes and damaged 259 others, and 15 trailers and 27 businesses were damaged or destroyed. The tornado also destroyed five homes in Ragland, where 48 others were damaged.[20]
1 death – This was probably a family of skipping and shorter-lived tornadoes. In Florida, 25 homes and trailers were torn apart. In Georgia, many trees were snapped and uprooted, and buildings were destroyed at an industrial park. 100 homes and 50 trailers were damaged in Georgia as well. A total of 18 people were injured.[20]
A brief tornado overturned trailers and tore roofs from several homes, and businesses in the area were destroyed.[20]
Blizzard
As the storm system began to move northeastward out of Oklahoma, the cool air pulled down behind the system interacted with the moisture being pulled northward to produce snow over a large part of the Midwest. The snow began falling on Friday, January 10 and continued for the next two days. Snowfall of a foot (30.5 cm) or more was common from Nebraska to Minnesota, with 27 inches (69 cm) in Riverton, Minnesota.[28] The heaviest snow fell to the west of the low pressure center, which tracked from northeast Iowa through central Minnesota up to Lake Superior.[2] Sustained winds of 30–50 mph (48–80 km/h) with gusts from 70–90 mph (110–140 km/h) produced snowdrifts up to 20 feet (6 m) in some locations.[29]
Record low pressures were recorded in communities in Nebraska, Minnesota, Illinois, and Wisconsin, with a low of 28.55 in (0.725 m)b) in Duluth, Minnesota. Approximately 58 people died from effects of the blizzard and over 100,000 farm animals were lost.[32] The combination of snowfall totals, wind velocities, and cold temperatures made this one of the most severe blizzards the Upper Midwest has experienced.[30]
Record events
This storm system had, in part, a large effect on the weather in the entire eastern half of the country. A number of different weather records (at the time) were set during the four days of this storm, especially in daily high temperatures, wind gusts, low barometric pressure readings, and number of tornadoes.[1]
^An outbreak is generally defined as a group of at least six tornadoes (the number sometimes varies slightly according to local climatology) with no more than a six-hour gap between individual tornadoes. An outbreak sequence, prior to (after) the start of modern records in 1950, is defined as a period of no more than two (one) consecutive days without at least one significant (F2 or stronger) tornado.[4]
^Historically, the number of tornadoes globally and in the United States was and is likely underrepresented: research by Grazulis on annual tornado activity suggests that, as of 2001, only 53% of yearly U.S. tornadoes were officially recorded. Documentation of tornadoes outside the United States was historically less exhaustive, owing to the lack of monitors in many nations and, in some cases, to internal political controls on public information.[9] Most countries only recorded tornadoes that produced severe damage or loss of life.[10] Significant low biases in U.S. tornado counts likely occurred through the early 1990s, when advanced NEXRAD was first installed and the National Weather Service began comprehensively verifying tornado occurrences.[11]
^The Fujita scale was devised under the aegis of scientist T. Theodore Fujita in the early 1970s. Prior to the advent of the scale in 1971, tornadoes in the United States were officially unrated.[13][14] Tornado ratings were retroactively applied to events prior to the formal adoption of the F-scale by the National Weather Service.[15] While the Fujita scale has been superseded by the Enhanced Fujita scale in the U.S. since February 1, 2007,[16] Canada used the old scale until April 1, 2013;[17] nations elsewhere, like the United Kingdom, apply other classifications such as the TORRO scale.[18]
^Edwards, Roger (March 5, 2015). "Enhanced F Scale for Tornado Damage". The Online Tornado FAQ (by Roger Edwards, SPC). Storm Prediction Center. Retrieved February 25, 2016.
— (July 1993). Significant Tornadoes 1680–1991: A Chronology and Analysis of Events. St. Johnsbury, Vermont: The Tornado Project of Environmental Films. ISBN1-879362-03-1.