Worst tornado outbreak in Twin Cities 55 years ago

For Minnesotans of a certain age, May 6, 1965 is still a vivid memory. That is certainly true for this future meteorologist.

I’ve written several stories about that day here in Updraft.

Still, new angles come to light each year. Here are some specifics that are still striking to me 55 years and dozens of tornado outbreaks later.

• Seven tornadoes touched down in about three hours

• Four tornadoes were on the ground at the same time

• Four tornadoes were rated F4 (Fujita Scale) (winds 207 mph+)

• One tornado was F3 (winds 158 mph+)

• One tornado was F2 (winds 113 mph+)

• Thirteen killed, 500 injured, 51-million in damage

• First use of civil defense sirens for severe weather

• Some areas in Fridley were hit twice by two separate tornadoes.

Primitive radar saved lives

Take a look at the radar weather app on your phone. Now take a look at what meteorologists at the Twin Cities NWS had to work with on May 6, 1965. Could you easily find the tornadoes?

It’s amazing the Twin Cities NWS issued such accurate tornado warnings that evening.

Tornado climatology

Tornado frequency in Minnesota peaks in the days surrounding June 19. But the most violent (EF-4 and EF-5) tornadoes are more frequent earlier in the season. This makes sense since the contrast of air masses fueling the storms is often greater in early spring.

The 1965 tornado outbreak occurred earlier in the season like many of Minnesota’s most violent outbreaks.

Could it happen again?

Local experts who study tornado frequency say we’re overdue for another outbreak of multiple tornadic supercells in the Twin Cities. If an outbreak close to 1965 happens now, the damage will be much more severe.

Here’s what the 1965 tornado tracks look like laid over 2000 census data. Thousands more homes and Twin Citians would be in harm’s way.

There’s a map I hope to never see repeated again.