Palm Sunday Tornado Outbreak: April 11, 1965
This tornado outbreak was the second largest in recorded history. The largest occurred in early April 1974. There is a theme here; the super tornado outbreaks occur early in the spring when the temperature contrast is the largest and hence the winds at all levels of the atmosphere the strongest.
The pattern leading up to this severe weather event featured record cold and snow during the second half of March. In fact, March 1965 with a mean temperature of 16.9 was the coldest at the National Weather Service (NWS) site near Negaunee until the 15.6 degree mean set in the brutal winter of 2014. Spring finally made a push to the north during the second week of April 1965 and set the stage for disaster.
Southeastern Lower Michigan was hit hard. Several F-4 tornadoes raked the region. Scores were killed and damage was well into the multi-millions of dollars. In all, 47 tornadoes were confirmed from Michigan to Alabama with 271 people killed.
Farther north, Upper Michigan was the place to be on April 11, 1965. It was an unpleasant, raw day. However, we were on the cold side of the system that besieged the southern part of the state. In Marquette, the Weather Bureau (now the NWS) reported 0.23 inches of rain with a high of 42 and a low of 33 degrees.
After a bitter start to April, a dramatic turnaround is in the works. The cold trough that has developed near us over and over again since the beginning of April will be replaced by a warm upper-level ridge. The literal opposite weather conditions are expected with this pattern change. There will be some lake-effect snow tonight and one last disturbance with some snow over parts of Upper Michigan Tuesday night and then the warm up begins. Temperatures should warm each day from Wednesday through the end of the week. By the weekend, much of Upper Michigan should be in the 60s.