Because he was on duty at the time, he wasn’t able to go out and spot the storm for the National Weather Service, like his fellow weather spotters in the area did.
Once the ambulance service received a call for mutual aid in Comfrey, Gappa, who coordinates a group of weather spotters in Watonwan County for the NWS, got to see the historic storm firsthand as his ambulance made its way to Comfrey.
“It was just so huge,” he recalled, pausing. “It looked like no other tornado I’ve seen.”
Even though he and his group get paged by the county each time the NWS issues a warning or a watch for their area, Gappa has only seen three actual tornadoes; the largest was the 1998 tornado, followed by one that came near St. James two years ago and another one that touched down between Le Center and Mankato.
Regardless of whether the group actually gets to see a significant storm, they report information that gets relayed back to the NWS and then to news outlets, who relay it to the public.
Gathering information on weather that can move constantly and change rapidly takes a county-wide effort. Gappa coordinates a group called an Emergency Command Information Network, or ECIN, which consists of about 20 to 25 people. Every time Watonwan County is put into a watch, the spotters in Gappa’s group will check in with him on their two-way radios, which Watowan County’s emergency management department provides for them.
Weather spotters work with Skywarn, a program started by the NWS in the 1970s that works with local organizations and private citizens to get critical weather information during times of severe weather.
There are few ECINs in the area, since law enforcement agencies and fire departments have many of the weather spotters in this area.
“I think it’s a bad habit. People like to go out and look at storms. If you do that, you should know what you’re doing,” said Julie Peterson, emergency management director for Watonwan County.
People who are interested in becoming spotters have to attend one of the NWS’s training sessions, where they learn what to look for when keeping an eye on the weather and how to watch weather safely. Skywarn classes are two hours long and teach people about how to safely observe and identify weather conditions.
NWS meteorologist Todd Krause trains groups like Gappa’s across a 51-county area that stretches across the bottom of Minnesota into South Dakota, Iowa and Wisconsin.
Speaking at the St. James fire hall for the county’s annual Skywarn spotter training, Krause reviewed the basics of weather spotting.
He said many different scenarios can unfold once spotters are out in the field. Ideally, they have a two-day advance warning, but can also find themselves in situations where weather is rapidly changing and can go from being harmless to a full-blown tornado in about 10 minutes. There are also situations where the direction the weather takes is conditional, depending on how the elements of the storm move.
Spotters are supposed to look at the sheer of a cloud as well as its spin to tell what a cloud is doing.
Spotters are “the eyes” of the National Weather Service because although the doppler radar in Chanhassen can give meteorologist a general idea of what is happening and can infer that a storm is happening based on the radar picture, they can’t actually know what is happening in an area without spotters.
The process that brings information in from the field works like this: the NWS watches its radar and then decides whether to issue a watch or a warning for a particular area and then alerts law enforcement agencies, typically the county sheriff’s department, which page groups like Gappa’s over its radio frequencies.
Once paged, the spotters who are available to work check in with Gappa on their portable, two-way radios.
Spotters are supposed to report tornadoes, funnel clouds, wall clouds, hail, wind damage, wind speeds and flash flooding when they are out in the field. Safety, Krause said, is “critical.”
A tornado has a life cycle. It starts out as a towering cloud and, as updrafts and downdrafts of wind increase, the likelihood that the cloud will turn into a tornado greatly increases. Dissipation marks the end of the life of a tornado, although severe weather is still possible.
Tornadoes generally like areas where weather is warm and humid and air is rising up. They generally do not like rain, he said.
Normally, when tornadoes are 20 miles away or more, spotters typically don’t go out, but when they are in between 10 and 20 miles away, they can start to see cloud features and the rotation of the storm and get an even better view when the storm is five to 10 miles away because they can see where the rain is and they can see the storm’s base.
“When you see a rotating storm, you should be thinking severe weather,” Krause said.
Lots of spotters get concerned about the appearance of wall clouds, but Krause said they’re nothing special although they serve as markers of where the strongest updrafts and inflow of wind are taking place. Wall clouds typically point the direction that a storm will take. Krause recommends that spotters follow them from behind.
Of the many dangerous wall clouds only one in 15 will produce a tornado. The wall clouds that are closest to the ground are the most capable of becoming a tornado, especially when they last longer than 20 minutes and have a strong or increasing rotation.
Weather spotters aren’t required to take notes while they are out in the field, but Gappa keeps records of which spotters call in, of when they make their calls and what they report when they call so that when the NWS calls him for information, he can give an answer.
“It’s one-hundred percent volunteer. I can’t make ‘em jump in their car and go someplace they don’t want to go!,” he said with a laugh.
Gappa was a spotter for three years before the other members of the group asked him to coordinate it. He said spring and summer are usually the times when his ECIN is most active.
“Usually, we’re busiest in May to June and then August, but it can happen just about any time time,” he said.
Gappa said he likes being a spotter because it’s an important job since the NWS radar can only see so much and because people rely on spotters’ reports to tell them when to take cover.
“I’ve always been interested in public safety. I’m on the fire department and the ambulance service. My day job is a 911 dispatcher,” he said.
National Weather Service Meteorologist Todd Krause teaches the annual Skywarn weather spotting class at the firehall in St. James.