ST. LOUIS — National Weather Service (NWS) survey crews are investigating damage around the St. Louis region from a severe storm system early Tuesday morning.
Numerous counties in the 5 On Your Side coverage area were hunkered down after multiple tornado warnings were issued by the NWS. The survey crews traveled to areas where damage was reported to confirm whether suspected tornadoes touched down.
So far, NWS has officially confirmed three St. Louis area tornadoes. They include:
- A tornado with gusts up to 100 mph started near Sullivan High School and ended near the eastern edge of Meramec State Park.
- A tornado with gusts up to 80 mph southeast of Burbon near Blue Springs Creek Conservation Area.
- A tornado with gusts up to 76 mph went through a neighborhood northwest of Defiance.
NWS said its survey crews are done for the day as no other areas reported potential tornado damage.
How do meteorologists figure out whether a tornado happened or not? Radars and electronics can only tell NWS meteorologists so much. To figure out whether a tornado happened, the service has to head out into the field. Less than 24 hours after the storms, the agency sent out multiple survey teams to assess damage and figure out whether a legitimate tornado touchdown occurred.
"The pattern of damage determines if it was a tornado. NOT how much damage was caused," NWS said on its website. "We conduct surveys to find out exactly what happened. This helps us to improve our warnings for the future. This is also important for historical reference."
Tornado damage can often be confused with damage from a microburst, so meteorologists look at the type of damage rather than how much damage occurred.
Damage from a tornado often looks chaotic and leaves large trees uprooted and often crossing each other on the ground, the service said. Smaller snapped branches or trees aren't usually helpful, since those don't convey the true severity of winds.
For example, NWS originally said in a tweet on March 14 that a tornado was confirmed near Maeystown, Illinois. However, around half a dozen surveyors went to the area the next day and couldn't find any damage indicating a tornado was in the area.
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