BLUE EARTH - Early warning can save lives, Todd Krause of the National Weather Service said Thursday when he addressed a group of more than two dozen storm spotters at the Blue Earth fire station.
The meeting was a training session for people who want to monitor storms as they develop, but there were many good pointers citizens can use to keep themselves safe.
"Last year was a rather big year for tornadoes," Krause said, noting that Minnesota was No. 1 in that category. "I hope we don't get No. 1 again."
Tornadoes ripped through the Upper Midwest on June 17, 2010, spawning 74 tornadoes, with a record-setting 48 in Minnesota alone. Several cut through Faribault County.
The 74 tornadoes were the second-largest outbreak in summer of all time, Krause said. The tornadoes in Minnesota stretched from the Iowa border north to Roseau, about 30 miles from Canada.
With all the storms and damage, Krause marveled there were only three deaths.
"I'm shocked by how few fatalities there were," he said, crediting storm spotters for giving early warnings so people could find shelter. "I appreciate what you guys did."
Krause showed pictures of cloud formations and taught the group how to spot a wall cloud, which "is an attachment to the rain-free base and lower than it."
"Wall clouds are not tornadoes," he said, "Only about one out of 10 or 15 will give you a tornado.
"A wall cloud is nothing special, it just shows you where the condensation, inflow and updraft are," Krause said, but it's "the favored area for tornado formation."
Rain will lead the way and the wall cloud will follow it.
"Most chasers will stay a few miles away and let the storm pass left to right," Krause said, but keep in mind that tornadoes travel at a slight angle from the heavy rain boundary and sometimes the rain can wrap around the tornado.
The important thing about the wall cloud is whether it has rotation.
Watch the clouds for several minutes, he said. Look for a left-to-right rotation, not a steamroller top to bottom rotation, like you'd find in a shelf cloud. Shelf clouds do not spawn tornadoes, but they can deliver rain, hail and strong, gusty winds.
If you do have rotation, "you need to pay attention," Krause said.
When you have persistent rotation, is it speeding up? How strong is the wind at your back flowing toward the wall cloud? Is the wall cloud lowering?
"A wall cloud that's low to the ground is a lot more dangerous," Krause said.
Most people know what a funnel cloud looks like when it descends from the wall cloud, but what you need to watch for is a "rapidly rotating column of air and dust and debris swirling below," Krause said.
"Don't be fooled by look-alikes," Krause said. Scud clouds look like funnels, but have no rotation and nothing below.
He warned spotters about lightning. If they are outside when lightning is striking, they should seek shelter when the hair on the back of the neck stands up. Unlike with tornadoes, a vehicle is good shelter in a lightning storm because lightning will route around the metal vehicle to the ground.
To help track storms, Krause suggests people get a National Oceanic and Atmospheric Administration (NOAA) weather radio or follow weather.gov/twincities online, which has information on any weather, from tornadoes, to snowstorms, to high winds.
Krause warned that the tornado season can last for months. The earliest reported tornado was March 18, 1966, in Watonwan County. The latest reported tornado was Nov. 16, 1931, in Medina.
"Be aware of warnings and pay attention," he said. "Know where you will go ahead of time and be willing to seek shelter quickly."