Great Storm of 1975

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Great Storm of 1975 - Blizzard
January 11, 1975
January 11, 1975
Storm type: Cyclonic blizzard, Panhandle Hook
Formed: January 9, 1975
Dissipated: January 12, 1975
Maximum
amount1:		 27 in (68.6 cm) (Riverton, Minnesota)
Lowest
pressure:		 961 mbar (hPa)
Damages: 20 Million
Fatalities: 58
Areas affected: Midwest United States

1Maximum snowfall or ice accretion
Great Storm of 1975 - Tornado Outbreak
January 10, 1975
January 10, 1975
Date of tornado outbreak: January 9 – January 12, 1975
Duration1: ~ 72 hours
Maximum rated tornado2: F4 tornado
Tornadoes caused: 45
Damages: 43 Million
Fatalities: 12 deaths, 377 injuries
Areas affected: Southeast United States

1Time from first tornado to last tornado
2Most severe tornado damage; see Fujita Scale


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 storm system that pounded a large portion of the Central United States from January 9 to January 12, 1975. The storm produced 45 tornadoes in the Southeast U.S. resulting in 12 fatalities, while at the same time dropping up to 2 feet (68.6 cm) of snow and killing 58 in the Midwest.

Contents

[edit] Storm Overview

The storm originated over the the Pacific Ocean and crashed into the Northwest Pacific coast with damaging gale force winds on January 8, 1975.[1] By January 9, the storm 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 Northern Plains. The storm's central pressure bottomed out at 28.38 in (961 mb) just north of the Minnesota border in Canada.[2]

[edit] The Tornado Outbreak

Damage from an F3 tornado in St. Clair County, Alabama
Damage from an F3 tornado in St. Clair County, Alabama

As the storm system pulled out into the Central Plains strong storms and tornadoes almost immediately began to form. From January 9 to January 12 there were 45 tornadoes that touched down from Oklahoma to Florida, 41 of which touched down from 10 PM on January 9 to 10:00 PM on January 10.[3] What makes this tornadic event unusual is that daytime heating, typically a key ingridient in tornadic development, had very little impact on this situation.[4] The first two tornadoes in this outbreak occurred in Oklahoma and Louisiana after 10PM on January 9, and from there the progression of the twisters shifted in almost a steady eastward line through the overnight and then into the early morning hours. Texas saw 5 tornadoes between 1:30 AM – 3:30 AM, Arkansas had one twister at 6:00 in the morning, Louisiana saw 7 more tornadoes between 5:30 AM – 8:00 AM (killing one person), Mississippi had 5 tornadoes between 8:15 AM – 10:00 AM (killing 9), and Illinois & Indiana experienced 3 lunch hour tornadoes. The tornadic line of storms then shifted into Alabama (1 fatality) and Florida during the afternoon and evening hours.[3]

Mississippi and Alabama were the two states hardest hit by this outbreak. Alabama saw 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 AM killed 9 people and injured over 200. About half of the tornadoes on this day touched down between 5 AM - 12 PM local time. The 39 tornadoes that touched down on January 10 was the most active tornadic day in January in U.S. history at that time.[5] This outbreak was responsible for the majority of the 52 tornadoes that touched down in January of 1975. That figure also set a record at the time. Both of these records were broken in January of 1999.[6]

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 was done it had produced 45 tornadoes. There were 12 fatalities, 377 more injured and $42 Million in damages.[3]

[edit] Tornado Table

Confirmed
Total		 Confirmed
F0		 Confirmed
F1		 Confirmed
F2		 Confirmed
F3		 Confirmed
F4		 Confirmed
F5
44 1 27 13 1 1 0
Outbreak death toll
State Total County County
total
Alabama 1 St. Clair 1
Florida 1 Bay 1
Louisiana 1 Acadia 1
Mississippi 9 Lincoln 5
Pike 4
Totals 12
All deaths were tornado-related

[edit] The Blizzard

As the storm system began to move northeastward out of Oklahoma, the cool air behind 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 a high amount of 27 in (68.6 cm) in Riverton, Minnesota.[7] 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 kph) with gusts from 70 – 90 mph (113 – 145 kph) produced drifts of 15 – 20 feet (4.6 – 6.1 m) in some locations.[8] Some roads were closed for up to 11 days.[9]

Sioux Falls, South Dakota saw visibilities of below 1/4 mile (.4 km) for 24 straight hours, and just east of Sioux falls a 2000 foot (610 m) broadcast tower collapsed under the storms fury.[10] In Omaha, Nebraska a foot (31 cm) of snow fell, Sioux Falls saw 7 in (17.8 cm), Duluth, Minnesota saw 8 in (20.3 cm), International Falls, Minnesota saw 23.5 in (59.7 cm).

Record low pressures were recorded in communities in Nebraska, Minnesota, Illinois and Wisconsin, with a low of 28.55 in (966.8 mb) in Duluth, Minnesota. In all, approximately 58 people died in the storm and over 100,000 farm animals were lost.[11]

[edit] Record Events

This storm system had, in part, a large affect on the weather in the entire eastern half of the country. A number of different weather records were set during the four days of this storm, especially in daily high temperatures, wind gusts and low barometric pressure readings.[1]

[edit] Record High Temps

[edit] Record Wind Gusts

[edit] Record Low Pressure Readings

[edit] References

  1. ^ a b Wagner, A. James. "Weather and Circulation of January 1975". Monthly Weather Review 103: 360 - 367. Retrieved on 2006-12-14. 
  2. ^ a b Bruce Watson. 1975 Blizzard [video, .ram]. http://www.tpt.org/almanac/archive/archive.2000-1q.html: PBS.
  3. ^ a b c Storm Event Database. NCDC. Retrieved on 2006-12-14.
  4. ^ Forces of Nature. National Geographic. Retrieved on 2006-12-14.
  5. ^ Tornado Outbreak, January 21, 1999. NOAA (2003-11-19). Retrieved on 2006-12-14.
  6. ^ JANUARY TORNADO NUMBER BREAKS NATIONAL RECORDS. NOAA (1999-02-09). Retrieved on 2006-12-14.
  7. ^ A Century of Wisconsin Weather in Review. NWS - Milwaukee. Retrieved on 2006-12-14.
  8. ^ Memorable Northland Storms. NWS - Duluth. Retrieved on 2006-12-14.
  9. ^ A Prairie Home Companion. Minnesota Public Radio. Retrieved on 2006-12-14.
  10. ^ Big Weather Events of the 20th Century at Sioux Falls, SD. NWS - Sioux Falls. Retrieved on 2006-12-14.
  11. ^ Siouxland Weather History and Trivia January. NWS - Sioux Falls. Retrieved on 2006-12-14.
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