Bill Burton: It's time for us to take a look at the Science Behind the Forecast as I am joined by WAVE 3 meteorologist Tawana Andrew. Good morning, Tawana.
Tawana Andrew: Good morning. Today we're talking about something that happens after a tornado passes by.
BB: Yeah, it can be very difficult, at least initially, to know exactly how bad the damage from a tornado was, and that's where this comes in. It's tornado surveys. Tell us about this.
TA: So the National Weather Service, they are amazing and they're the ones who do these crucial tornado surveys that are great for understanding the intensity, the track of tornadoes, and improving tornado forecasting. So usually within 12 to 24 hours of a tornado or damage of some sort, the National Weather Service meteorologists will go to the damage zone to complete a tornado survey or a storm survey. And depending on the weather pattern, they may have to wait for even additional storms to track through a region before they even start a storm survey. And I've even seen situations where the National Weather Service meteorologists, they'll work an incredibly long, maybe 10 to 12 hour shift issuing warnings throughout the night, and then the next day they'll be out surveying and then they'll be back to issuing warnings later on. So it's a lot of work. They are very, very dedicated. people trying to make sure that we know what's happening when it's happening and trying to figure out what happened after all the storms have moved through. So they have these really adorable, I find them adorable, damage survey kits, and they include cell phones, a tablet with the damaged survey software on it, an atlas, and a notebook. And in recent years, drones have become a big and vital part of storm surveys.
BB: That makes sense. You can see so much with them.
TA: Exactly, and that aerial view is great because it helps first to figure out what happened because the first task of a survey team is to figure out if it was actually a tornado because you can get tornado-like damage with microbursts or macro bursts or straight line winds. So first, you got to figure out if there was actually a tornado. And the direction of which the trees and other debris are thrown that can provide that information, which the drone is, or sometimes even a helicopter, can be absolutely great for. Next, they are looking at all of the impacted structures or vegetation to determine the path, the width and the length of a tornado's track. They use the Enhanced Fujita system, so the Enhanced Fujita scale, the EF scale to assign a strength rating to the damage categorizing tornadoes either from an EF0, which is the weakest, to an EF5, which is the strongest, and the tornado is rated based on the most severe damage in its path. So let's say, for example, that we have an EF2 tornado that has been rated by the National Weather Service, but along its 20 mile track, it's mostly EF0 or EF1 damage. But if there is one structure in that 20 mile path that has EF2 level damage, then it will be rated as an EF2 because that's the worst it did. So that's how they, rate those tornadoes and the tornado's wind speed, direction, duration over specific locations, all of that is very vital to understanding how a tornado actually behaves because sometimes they can skip up and down as they travel, so they go back up into the cloud and back down or I've seen tornadoes travel in kind of a loop in some scenarios. So it's important to figure out where it was and when and the damage that it caused as it moves through.
BB: And we know all of this now thanks to this edition of Science Behind the Forecast with WAVE 3 meteorologist Tawana Andrew. Thanks for the knowledge, Tawana.
TA: Of course.
This transcript was edited for clarity
