Helene's river flooding threat continues in Southeast

  • 2 weeks ago
AccuWeather's Flooding Expert Alex Sosnowski shares the latest updates on the flood threat left behind by Helene that continues to plague the southeastern region of the United States.
Transcript
00:00Alex, let's start with the timeline you and I put together for Friday and how things have moved on
00:05through the weekend and now into this week. You know, what we saw, of course, was the flash
00:10flooding of the streams and rivers in the higher elevations. Elevation makes a big difference.
00:15You get rapid runoff there in the southern Appalachians, and that's exactly what occurred.
00:20On a tremendous scale, though, with this, when you get one to two feet of rain,
00:23there's not an infrastructure really that can handle that kind of rain in the few hours that
00:28they had. But then as that water works downstream, whether you get rain downstream or not, you still
00:34have to deal with the surge coming downstream. So we saw the mid-state flooding going on
00:39pretty much later this week and into the start of this week. Now we're looking farther out,
00:44farther down into the lowlands, closer to sea level. That's where we're seeing the surge coming
00:49here. And some places we're going to be looking at significant flooding, but certainly not on the
00:54scale that we had back in the southern Appalachians. It's a slower moving flood situation near the
01:00coast, not a rapid flood situation like we had back up in the southern Appalachians.
01:06So we're right on track here with that flooding that has moved further downstream. You take a
01:11look here at some of the river gauges, and you can see the different colors representing that
01:16there are some in major flood stage. Yeah, and the yellow ones on there are action stage, where
01:22we're getting up not quite to minor flood stage, but we're getting close. This will not have the
01:28scope or the magnitude of the flooding that occurred, the disastrous and deadly flooding
01:32that occurred up in the southern Appalachians. This is slower moving, and because you didn't
01:37have the big rain and a good chunk of this area here hitting at the same time, you're just dealing
01:42with what happened upstream pretty much. And those red and purples, you're looking at moderate and
01:47major flood states. Not too many in the major states, fortunately.
01:51Your expertise told you that it would take a few days to see that flooding
01:55further towards the coast, and it shows that well in the Santee River.
01:58Yeah, the Santee River is just a bit above sea level there, and this is at Jamestown,
02:04and you can see that we're not going to get a crest there until this weekend coming up.
02:10So that's how long it takes some of these rivers to cycle through. You can get the flooding
02:14upstream within hours, and then downstream near the coast, it can take days if not a week or more.
02:19That's a really helpful perspective. All right, we look at kind of positives from,
02:23of course, what has been an absolutely devastating catastrophe. When you look at the 30-day rainfall,
02:27you can see all of the green that filled in, and that's going to be beneficial rain along the
02:32Mississippi. Yeah, we're already seeing a response on the Ohio and the Mississippi.
02:37That'll help with the barge operation. So if there is one positive out of this, they got
02:42rain out there, but they didn't have the scope of the flooding, of course, that we had in the
02:46southern Appalachian. So very beneficial there. You can see the drought that was in place.
02:50That'll be kind of taken away a little bit there in part of the Ohio, Tennessee, and lower
02:56Mississippi Basin. So some good news there. Water levels will be up. They'll be out of the brown
03:01and into the green. That'll help with the barge operations for a little bit, especially if this
03:05port situation goes on. We might be relying a little bit more, perhaps, on the Mississippi
03:09here for transport. And Alex, you know as well as I do here at AccuWeather, we like to give advance
03:14notice. So we are tracking the next thing in the tropics, and that could impact areas that
03:19were hard hit from Helene. Yeah, one thing, one point we want to make, we're not getting any
03:26information here that's suggesting that we're going to get big rains in the southern Appalachians
03:29out of this. There's a minor system coming on Friday, like basically a front. That can produce
03:34some downpours, and with the damaged infrastructure, you can have some flash flooding problems there.
03:39But we're not going to get like a Helene-type repeat going on in the southern Appalachians.
03:43But it is Florida. As Bernie's saying, Florida, Florida, Florida. You got to watch this thing. We
03:47could, from a freshwater standpoint, there certainly can be river flooding going on for the middle and
03:52latter part of next week. AccuWeather flooding expert Alex Anowski, thank you so much for
03:57helping break that down this morning. My pleasure.

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