Great Storm of 1975

Infobox cyclone|name=Great Storm of 1975 - Blizzard and Tornado Outbreak
image location=NOAA_map_of_Minnesota.jpg


stormtype=Cyclone, Panhandle Hook
date formed=January 9, 1975
date dissipated=January 12, 1975
maximum amount=27 in (68.6 cm) (Riverton, Minnesota)
pressure=28.38 inches (inHg)
snow fatalities=58
tornado fatalities=12 deaths, 377 injuries
fujitascale=F4
tornadoes=45
total snow damages (USD)=$20 million
total tornado damages (USD)=$43 million
areas affected=Midwest and Southeast United States

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 impacted a large portion of the Central and Southeast United States from January 9 to January 12, 1975. The storm produced 45 tornadoes in the Southeast U.S. resulting in 12 fatalities, while later dropping over convert|2|ft|cm of snow and killing 58 people in the Midwest. This storm 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.cite journal | last = Wagner | first = A. James | title = Weather and Circulation of January 1975 | journal = Monthly Weather Review | volume = 103 | pages = 360–367 | publisher = Allen Press | url = http://ams.allenpress.com/archive/1520-0493/103/4/pdf/i1520-0493-103-4-360.pdf | accessdate = 2006-12-14 | doi = 10.1175/1520-0493(1975)103<0360:WACOJ>2.0.CO;2 | year = 1975 | doilabel = 10.1175/1520-0493(1975)1030360:WACOJ2.0.CO;2] 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 in (961 mb) just north of the Minnesota border in Canada.cite web | last = Watson | first = Bruce | title = 1975 Blizzard | publisher = PBS | date = January 7, 2000 | url = http://www.tpt.org/almanac/archive/1616clip6.ram | format = .ram | accessdate = 2007-05-21 ]

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. [cite web | author = National Geographic | title = Forces of Nature | url = http://www.nationalgeographic.com/forcesofnature/interactive/index.html?section=t | accessdate = 2006-12-14 ] 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 in the outbreak 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.&ndash;3:30 a.m., one tornado touched down in Arkansas at 6:00 a.m., Louisiana saw seven tornadoes between 5:30 a.m.&ndash;8:00 a.m. (killing one person), Mississippi had five tornadoes between 8:15 a.m.&ndash;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.cite web | author = NCDC | title = Storm Event Database | url = http://www4.ncdc.noaa.gov/cgi-win/wwcgi.dll?wwevent~storms | accessdate = 2006-12-14 ]

January 12 event

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 convert|27|in|cm|0 in Riverton, Minnesota. [cite web | author = NWS - Milwaukee | title = A Century of Wisconsin Weather in Review | url = http://www.crh.noaa.gov/mkx/wiwx.php | accessdate = 2006-12-14 ] The heaviest snow fell to the west of the low pressure center, which tracked from northeast Iowa through central Minnesota up to Lake Superior. Sustained winds of 30 &ndash; 50 mph (48 &ndash; 80 km/h) with gusts from 70 &ndash; 90 mph (113 &ndash; 145 km/h) produced snowdrifts up to convert|20|ft|m|0 in some locations. [cite web | author = NWS - Duluth | title = Memorable Northland Storms | url = http://www.crh.noaa.gov/dlh/science/event_archive/arrowhead/arrowhead_winter.php | accessdate = 2006-12-14 ] Some roads were closed for up to 11 days. [cite web | author = Minnesota Public Radio | title = A Prairie Home Companion | url = http://prairiehome.publicradio.org/programs/20001028/winter.html | accessdate = 2006-12-14 ]

Sioux Falls, South Dakota saw visibilities of below convert|1/4|mi|km|1 for 24 straight hours, and just east of Sioux Falls a 2,000-foot (610 m) broadcast tower collapsed under the storm's fury.cite web | author = NWS - Sioux Falls | title = Big Weather Events of the 20th Century at Sioux Falls, SD | url = http://www.crh.noaa.gov/fsd/?n=20thcentury | accessdate = 2006-12-14 ] In Willmar, Minnesota, 168 passengers were trapped in a stranded train for hours, unable to walk to shelter because of dangerously low wind chill values.cite book | last = Seely | middle = W. | first = Mark | title = Minnesota Weather Almanac | publisher = Minnesota Historical Society press | year = 2006 | id = ISBN 0-87351-554-4] In Omaha, Nebraska a foot (31 cm) of snow fell, Sioux Falls saw convert|7|in|cm|0, Duluth, Minnesota saw convert|8|in|cm|0, and International Falls, Minnesota saw convert|24|in|cm|0.

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 from effects of the blizzard and over 100,000 farm animals were lost. [cite web | author = NWS - Sioux Falls | title = Siouxland Weather History and Trivia January | url = http://www.crh.noaa.gov/fsd/?n=suxtrivia01 | accessdate = 2006-12-14 ] The combination of snowfall totals, wind velocities, and cold temperatures made this one of the worst blizzards the Upper Midwest has experienced.

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.

Daily high temperatures

January 10

* Chicago, Illinois: 60 °F (15.6 °C)
* Indianapolis, Indiana: 62 °F (16.7 °C)
* Louisville, Kentucky: 66 °F (18.9 °C)
* South Bend, Indiana: 61 °F (16.1 °C)

January 11

* New York City, New York: 65 °F (18.3 °C)
* Providence, Rhode Island: 61 °F (16.1 °C)
* Washington DC: 75 °F (23.9 °C)

Low pressure measurements

* Duluth, Minnesota: 28.55 in (966.8 mb)
* Minneapolis, Minnesota: 28.62 in (969.2 mb)
* Rochester, Minnesota: 28.67 in (970.9 mb)
* Milwaukee, Wisconsin: 28.86 in (977.3 mb)
* Rockford, Illinois: 28.87 in (977.6 mb)
* St. Louis, Missouri: 28.93 in (979.7 mb)

Tornadoes

* Most tornadoes on one day in January: 39
* Most tornadoes in the United States during January: 52

ee also

* List of Minnesota weather records
* List of North American tornadoes and tornado outbreaks

References

External links

* [http://www.brainerddispatch.com/history/pages/1024/1024_Blizzard_01111975.jpgBrainerd Daily Dispatch front page, January 11, 1975]