1965 Palm Sunday tornado outbreak
The first (and more famous) Palm Sunday Tornado Outbreak occurred on April 11, 1965 and is the second-biggest tornado outbreak on record, after the Super Outbreak of April 3, 1974. Fifty-one tornadoes were involved in the outbreak, which killed 256 people. It occurred on Palm Sunday, an important day in the Christian religion, and many people were attending services at church, one possible reason why some warnings were not received. There had been a short winter that year, and as the day progressed, the temperature rose to 83° F in some areas of the Midwest.
A second Palm Sunday tornado outbreak occurred on March 27, 1994 in Alabama, killing 24: see Palm Sunday Tornado Outbreak II.
The moving storm
At around 1 P.M. on April 3, 1974, the first tornado of the day occurred in Clinton County, Iowa. It was an F4 on the Fujita scale of severity. Later in the day, the tornadoes started to become more intense. By the time the storm system got to Indiana, there were several series of tornadoes, some of them lethal. The first touched down at around 5:30 P.M. in Koontz Lake, Indiana. This massive F4 killed 10 people and injured 180. The second to hit was in Wakarusa, Indiana, where it devastated the Midway Trailer Park. The next touched down near Goshen, Indiana and moved northeast. The community of Rainbow Lake was completely destroyed, with only the foundations of homes still remaining.
The only F5 tornado of the outbreak formed near Wyatt, Indiana, and moved east-northeast toward the town of Dunlap, Indiana (this is the tornado pictured above right). This was the infamous "double tornado" that hit the Sunnyside subdivision. Most of the 36 people killed in the double tornado had no warning because the high winds had knocked out the telephone and power grids. For the first time in the U.S. Weather Bureau's history, all nine counties in the northern Indiana office's jurisdiction were under a tornado warning. This is called a "blanket tornado warning."
With the telephone lines down, emergency services in Elkhart County, Indiana could not warn the people in Michigan that the tornadoes were headed their way. In Michigan, tornadoes hit as far north as Allendale, in Ottawa County, Michigan, just east of Grand Rapids. Out of the southernmost counties of Michigan, all but three (Berrien, Cass, and St. Joseph counties) were hit.
A mile-wide tornado hit in Milan, Michigan, near Detroit. It destroyed the building of Wolverine Plastics (the top employer in Milan), completely removing the roof.
Twenty-five people were killed by an 800-yard tornado hitting near Kokomo, Indiana. Marion, Indiana, and Alto, Indiana were severely impacted as well. More tornadoes moved into Ohio from Indiana, wreaking devastation as they came. A double tornado was sighted near Toledo, Ohio.
The aftermath
The U.S. Weather Bureau later investigated why so many people died in this event. Radar stations were few and far between in 1965, so tornadoes were identified by the characteristic shape of "hook echoes", but the danger in this storm was identified in plenty of time. The real answer was simple: the warning system failed. The Bureau disseminated the warnings quickly, but the public never received them. Additionally, the public did not know the difference between a Forecast and an Alert. Thus the current Tornado watch and Tornado warning program was implemented because of the terrible death toll from the Palm Sunday outbreak.
Technology has grown tremendously since 1965; warnings can now be spread via cable and satellite television, PCs and the Internet, solid-state electronics, cell phones, and NOAA Weatheradio.
Suction vortices
Dr. Ted Fujita discovered suction vortices during the Palm Sunday tornado outbreak. It had been believed that the reason why tornadoes could hit one house and left another across the street completely unscathed was because the whole tornado would "jump" from one house to another. However, the actual reason is because most of the destruction is caused by suction vortices: small, intense mini-tornadoes within the main tornado.