Small change in radar leads to big changes in Pine Belt forecasting

Small change in radar leads to big changes in Pine Belt forecasting

HATTIESBURG, Miss. (WDAM) - Severe weather is a common occurrence here in South Mississippi, and the first thing we look at when storms strike is radar.

You can see it on TV, on the Internet and even on your phone. But for years, the radar coverage was subpar. And while the average person never saw the issue, to meteorologists, it was a thorn in our side.

So, what was the problem with the radar? Well, it was scanning too high into the storm and not scanning the part of the storm we needed to see, closer to the ground.

“Over time, there has definitely been a lot of discussion about having better radar coverage," said Eric Carpenter, a meteorologist with the National Weather Service. "And one of the easiest ways to do that, other than actually building radars or more radars, is to take the current radars and lower the radar beam down just slightly.”

And while this is as easy as pushing a button, we are talking about the federal government, of course. Which means red tape, bureaucracy and a 71-page environmental and health study.

After months and months of waiting, the Weather Service in Jackson was finally allowed to lower the radar beam.

The National Weather Service Doppler Radar in Brandon is located inside a white ball on top of a tower. Inside is a giant dish.

They dropped that dish by 0.2 degrees. And while that sounds like a very small change, it’s made a drastic difference for the Pine Belt.

“So, in severe thunderstorm with tornadoes, there’s a lot of critical processes that go on in the lowest few thousand feet," Carpenter said. "Just missing a few hundred feet of the storm at the lowest levels can make a big difference in what you’re seeing as far as the rotation.”

And being able to see a few thousand feet lower can mean the difference of minutes when it comes to issuing warnings.

So how can a change that small impact us in Hattiesburg? It’s because of trigonometry. You know, that very boring math back in high school.

So, what happens? Well, the further away you get from the radar, the higher the beam is in the air. By the time the beam got to Hattiesburg and Laurel, it was 7,000 feet in the air.

With the new scheme, the beam is only 4,000 feet in the air. A much better improvement.

“So, with that that extra information, we have more confidence with our warnings," Carpenter said. “We can put in more details. We’re confident that a particular tornado is going to be worse. To have that kind of information that gives us that extra confidence allows us to put that kind of information into the warnings, and people will take action work quickly. They are more apt to take action when they have that kind of information in the warnings and it keeps them safer as a result.”

And lead time is the name of the game. Because when severe weather strikes, an extra minute or two can literally mean the difference between life and death.

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