National Weather Service staff spent a second hectic day trying to determine the size and location of the slew of tornadoes that hit south Louisiana on Tuesday.
Five National Weather Service teams surveyed the extent of damage Wednesday to determine the strength of each tornado and track how long they stayed on the ground. Tornado strength is set by the Enhanced Fujita Scale, which uses a number of factors including the extent and types of damage.
The scale runs from EF-0 — the weakest tornadoes with three-second wind gusts estimated at between 65 and 85 miles per hour — to EF-5, the strongest with three-second wind gusts of more than 200 mph.
“You have to go out and look at it. There’s no other way to do it,” Ken Graham, meteorologist in charge at the National Weather Service Baton Rouge/New Orleans office, said of the survey work. The work reviews damage, the construction of structures as well as interviewing people who responded or were eyewitnesses.
As of Wednesday evening, the National Weather Service was reviewing a possible seven tornado tracks in southeast Louisiana and the number of tornadoes — one storm could have caused multiple tracks.
Here is a quick look at most of the circulations. Just about everyone one of these tracks had a tornado reported. pic.twitter.com/zzjAda2Rsa— NWS New Orleans (@NWSNewOrleans) February 24, 2016
The one that destroyed the trailer park in Convent was determined to be an EF-2, which correlates to an estimated three-second wind gust of between 111 and 135 mph.
“That’s what we consider a strong tornado,” said Michael Koziara, NWS meteorologist.
Other EF-2 tornadoes were found to have hit in Livingston Parish north of I-12, LaPlace and Paincourtville in Assumption Parish. The tornadoes that hit in Kenner south of the Louis Armstrong New Orleans International Airport and Madisonville were rated as EF-0.
Additional surveys might be done Thursday in the damaged areas of Prairieville and White Castle, Graham said.
The National Weather Service’s Lake Charles office also confirmed that damage to an area in southwest Louisiana between Baldwin and Franklin was caused by a tornado. The EF-1 tornado appears to have touched down in a sugarcane field around 2:30 p.m. Tuesday and traveled for 2.6 miles, damaging two businesses, 28 homes and snapping 20 telephone poles, meteorologist Tim Humphrey said. There were no injuries.
To have a cluster of tornados touch down in southeast Louisiana is a rare occurrence, Graham said, and in 22 years in the National Weather Service with 13 of them in Slidell, they’ve never had to deploy five tornado survey teams before.
“This was a big event for us,” he said. Graham added that this is “normally what you see is south Mississippi and Alabama. That’s the normal areas that get hose types of systems.”
Graham added that air pushing in from the Gulf of Mexico usually keeps conditions over Louisiana stable, but that wasn’t the case this time. Everything came together to provide the instability in the air to spawn tornadoes.
On Tuesday, the storms occurred during the day, and people had been warned in advance, prompting some government offices and schools closures.
“What if this had happened at night?” Graham said.
Follow Amy Wold on Twitter, @awold10.