11-04-2025
On This Date: The Palm Sunday 1965 Tornado Outbreak, One Of America's Worst
One April tornado outbreak was among the nation's most impactful, but also arguably one of the most important for the future of severe weather forecasting.
On April 11, 1965, 60 years ago today, 47 tornadoes tore across parts of the Midwest, from Indiana, Michigan and Ohio to northern Illinois, northeast Iowa and Wisconsin.
That may not sound like a lot of tornadoes in the context of what we've seen lately in early April and mid-March 2025. That's because our current technology (radar, smartphones, drones, etc.) allows meteorologists to detect more weak tornadoes today than in decades past, a concept called "tornado inflation".
But what set this event apart was the number of violent tornadoes - rated F/EF4 or F/EF5. Twenty-two such violent tornadoes were documented in the Palm Sunday outbreak. Former The Weather Channel severe weather expert Greg Forbes once calculated Palm Sunday 1965 had the highest percentage of violent tornadoes of any U.S. outbreak.
And it's the most intense tornadoes that typically claim the most lives. The tornadoes killed 260 and injured another 3,442.
Two areas were struck twice by violent tornadoes. Two F4 twisters 30 minutes apart raked over a similar track through Branch, Hillsdale, Lenawee and Monroe Counties, Michigan, claiming 44 lives. Another pair of F4 tornadoes hammered Elkhart County, Indiana, leaving 67 dead in their wake. A photo of a double funnel in Dunlap, Indiana, shown below has become the one of most infamous and iconic tornado photos.
While alerts were issued, Palm Sunday 1965 triggered improvements in the communication of threats from severe weather. Previous tornado "forecasts" would be called "watches", going forward.
Outdoor sirens would become increasingly utilized to warn people outdoors. Storm spotter networks, including amateur radio enthusiasts, would grow and become more organized. NOAA weather radio's network would grow, and a separate NOAA weather wire would also allow warnings to be transmitted more efficiently.
Palm Sunday 1965 was also the first outbreak studied via aerial survey by tornado science pioneer Theodore Fujita. In his study of the outbreak, Fujita discovered smaller, helical markings in the damage, indicative of more intense circulations embedded in tornadoes he called suction vortices.
Jonathan Erdman is a senior meteorologist at and has been covering national and international weather since 1996. Extreme and bizarre weather are his favorite topics. Reach out to him on Bluesky, X (formerly Twitter) and Facebook.
