April 1996 Tornado Outbreak Sequence

The April 1996 Tornado Outbreak Sequence was a series of tornado outbreaks that occurred over a three-day period between April 19 to April 21, 1996 across a large area of eastern North America. It was the most notable outbreak of the year; the 19th was the most prolific tornado outbreak in Illinois history.

Thirty-three tornadoes hit Illinois. It broke the old record of 25 set on August 10, 1974. This outbreak can also be compared to the May 2004 tornado outbreak sequence as it was a very huge, deep and vigorous system. The same system produced tornadoes in Ontario on the 20th; and destructive tornadoes also occurred in Arkansas and Texas on the 21st.

Meteorological sypnopsis

The outbreak occurred when the warm front of a deep storm system moved north and east out of Missouri. April 19 started off cool and skies were overcast ahead of the warm front. Meteorologists were trying to figure out if the warm front would move into Illinois that afternoon. As the day wore on, temperatures warmed, dew points rose, and thunderstorms started to explode in Iowa during the mid-afternoon hours. Although there were some doubts on specifics, the potential significance of the outbreak was rather foreseeable, with storm chasers traveling from the Great Plains and the Storm Prediction Center issuing a high risk early on.

The outbreak across the south-central U.S. on the 21st was produced by a different weather system.

April 19

Illinois

Thirty-three tornadoes hit Illinois and spread west and south into Missouri, and Iowa and east and north into Wisconsin, Michigan, and Indiana on Friday, April 19. The town of Decatur was hit by an F2 tornado (parts of Decatur were heavily damaged by a tornado on the previous night, April 18). That tornado later, after hitting eastern sections of Urbana, was over one mile in width, and hit Ogden as an upper end F3 tornado at 7:00 p.m., damaging or destroying nearly all 150 homes in the town, and killing one person. Surveyors said that the tornado also had multiple vortices, smaller destructive tornadoes within the parent cyclone.

Indiana

In Indiana, 21 unconfirmed tornadoes were produced as the cold front moved into the area during the evening hours. Temperatures had warmed well into the 70's and lower 80's (20 to 26°C) before the storms hit. Five people were injured in Morgan County.

April 20

Canada's most prolific tornado outbreak struck Ontario.

A vigorous branch of the jet stream from the Pacific Ocean combined with rich low-level moisture kept the storm system rolling, spinning off more tornadoes in the Southeast. One tornado hit Carroll County, Mississippi killing teenager Dexter Forman when a tree fell on his mobile home. Another tornado did massive damage to Berea, Kentucky but no one was killed.

April 21

On the 21st, while a final tornado was produced by the first system in southern Quebec, more tornadoes raked through Oklahoma and Arkansas, killing a father and son and two kids in St. Paul and Fort Smith, respectively.

117 tornadoes broke out in the Great Lakes, Midwest and Southeast region over the three-day period. The entire outbreak killed six people.

Tornado table

Confirmed tornadoes

April 19 event

ee also

*List of North American tornadoes and tornado outbreaks

References

External links

* [http://www.usatoday.com/weather/wtidx496.htm A wild weekend across the USA] (USA Today)
* [http://www.usatoday.com/weather/wt496ovr.htm Overview of the April 19 - 22, 1996 outbreak] (USA Today)
* [http://www.cnn.com/US/9604/20/storm.roundup/ Violent storms lash South, Midwest] (CNN)
* [http://www.crh.noaa.gov/dvn/WeatherEvents/galva_tornado/galva.php Galva, IL Tornado] (NWS Quad Cities, IA/IL)
* [http://ww2010.atmos.uiuc.edu/(Gh)/arch/cases/960419/home.rxml The Central Illinois Severe Weather Outbreak of April 19, 1996] (University of Illinois at Urbana-Champaign)
* [http://redrock.ncsa.uiuc.edu/~jewett/Apr19/ April 19, 1996 - Illinois Tornado Outbreak] (University of Illinois at Urbana-Champaign)
* [http://www.nws.noaa.gov/om/assessments/pdfs/ftsmith.pdf NWS Service Assessment {Ft. Smith and Van Buren, AR)]
* [http://redrock.ncsa.uiuc.edu/AOS/publications/SLS98/apr19.html Numerical Study of Severe Convection on April 19, 1996] (Proceedings, 19th Conference on Severe Local Storms, American Meteorological Society)
* [http://redrock.ncsa.uiuc.edu/AOS/publications/SLS00/jewett/ Initiation and Evolution of Severe Convection in the 19 April 1996 Illinois Tornado Outbreak] (Proceedings, 20th Conference on Severe Local Storms, American Meteorological Society)
* [http://www.nssl.noaa.gov/wrd/swat/mitchell/kilx041996.html The 19 April 1996 Central Illinois Severe/Tornado Event: A WSR-88D Perspective] (National Severe Storms Laboratory)
* [http://www.fema.gov/news/event.fema?published=1&id=684 Federal Disaster Declaration] (FEMA)
* [http://sphs.angeltowns.net/spcproductarchive/highrisk/past/041996otlkC.html 1900 UTC (2:00 p.m. CDT) Day 1 Outlook Text from April 19, 1996 (incomplete)]
* [http://sphs.angeltowns.net/spcproductarchive/highrisk/past/041996otlkB.html 1500 UTC (10:00 a.m. CDT) Day 1 Outlook Text (incomplete)]