FIRST ALERT: Tropical Storm Bertha forms (7/20/26)

[00:00:58]Hey, good evening South Mississippi.

[00:01:00]Chief Meteorologist Eric Johnson here.

[00:01:01]We're going to do a quick update on what is now Tropical Storm Bertha. If you've been following along earlier this evening at the 7:00 intermediate advisory put out by the National Hurricane Center, uh we found that well, Tropical Depression Two has strengthened into Tropical Storm Bertha. A minimal tropical storm winds of about 40 mph and it is barely drifting to the west-northwest at about 3 mph.

[00:01:28]Uh it is not moving very much. A little bit closer look here.

[00:01:32]And uh you can see uh it is a lopsided system. Notice how most of the thunderstorm activity is on the south side of the center of circulation and on the north side, we just have some weak spiraling rain bands and I think that's going to be the structure of Bertha as we go into the next 24 to 48 hours. If I remove the radar and kind of zoom back out, you can see the cloud cover and what we're seeing is new thunderstorms are beginning to kind of a blossom on the south side of uh tropical storm Bertha. And if I change the color here, you might see a little bit better. So, this shows you the temperature cloud top temperature and the red colors indicate colder cloud tops. So, with that, we're starting to see new thunderstorms beginning to develop here. Usually, when we see more thunderstorms developing on the south side of the center, that tends to kind of keep the center kind of wanting to grow towards that thunderstorm development. So, that could keep it a little bit further south on that track there. So, that's a trend uh we are going to monitor pretty closely there.

[00:02:43]So, we're starting to see a little bit of thunderstorm activity on the south side, but uh for the most part, it's still a lopsided system. It's moving over some pretty warm water.

[00:02:52]The water temperatures are in the mid to upper 80s, so uh water temperatures are not the problem. So, why is this not strengthening? Well, remember, the water in the Gulf could be, you know, 90 100°, but if all the ingredients aren't coming together for tropical development, then it's going to be hard for systems to really organize. The reason Bertha is struggling tonight is because of wind shear and dry air. And when we take a look uh at the water vapor, you can clearly see where Bertha is, the center here, and those deep thunderstorms that we were just looking at on the south side, the reason Notice how the steering currents here, the northerly winds, the northeasterly winds, are blowing all the thunderstorm tops off of the center of circulation. In order to get a tropical system to really organize, you need all these thunderstorms to develop over the center. As long as we have this wind shear in place, it's going to keep Bertha very disorganized. And when you take a look at the bigger picture, we have high pressure that is building over the central part of the country. You can tell that by the clockwise flow. Notice how everything is moving clockwise. The steering currents are clockwise. That's high pressure. This is going to gradually expand further east and the clockwise flow will gradually start to curve, Bertha, towards the west. But as it does so, it's going to impart even more wind shear on top of the storm. So, as that high builds, you can see this in the animation here as we go into Tuesday and Wednesday, as the high pressure builds across the southeast here, the steering currents, you know, steering it west along the Gulf Coast, but all of the wind shear is really going to kind of keep this very weak. And here's an idea of what it could look like as we go into the Tuesday time frame. I will say futurecast is probably a little bit faster than say the National Hurricane Center uh forecast track. Um but I am just going to show you this animation here of futurecast, just kind of giving you an idea of how lopsided this system could be.

[00:05:00]Uh we're looking at, you know, usually we think of tropical systems, the right side of the storm is typically the wet side and the worst side of the storm.

[00:05:09]Well, in this particular case, it looks like the south side of the storm is going to be the part of the storm that you don't want to be on. And we're going to be on the north side. Notice how on the northern half of the storm there's not much rain or shower or thunderstorm activity. And so, as we advance into Tuesday night into Wednesday morning, so here we are by 6:00 a.m.

[00:05:28]Wednesday, and again, futurecast is a little bit quicker than the National Hurricane Center forecast track, but it has what looks like the circulation over Plaquemines Parish in Louisiana. Now, keep in mind the forecast track, it certainly could be a little bit further north, it could be a little bit further south. Uh it certainly could track a little bit closer to the coast, but regardless, we're still thinking that the northern side of this storm is going to be uh the part of the storm that you don't necessarily want to be on, or you do want to be on, rather.

[00:06:03]Let me show you that forecast track.

[00:06:05]So, here we are. And this is what I mean when I say the forecast track is a little bit slower compared to future cast uh in the sense that future cast kind of has it coming in faster.

[00:06:19]Well, and we will get an update from the Hurricane Center at about 10:00, but uh you can see we have the center of the storm according to the Hurricane Center forecast track here uh around off the coast of South Mississippi around Wednesday afternoon. Now, keep in mind, the forecast cone shows you where the center of the storm is going in is going to track. It doesn't tell you anything about the impacts of the storm.

[00:06:46]It just tells you where the center of circulation may track. So, that center could go as far south as the south side of this cone.

[00:06:52]It could also go as far north as uh the northern edge. And I will say, the further north or inland the tropical storm can go, the more impacts we could see in South Mississippi. So, a more northerly track like this would mean more in the way of impacts for South Mississippi.

[00:07:11]Let me show you another animation just the rainfall. So, with this track and with the lopsided with the northern side being the dry side and the south side being the the wet side, this is what the rainfall is probably going to look like with this storm where most of the rain ends up falling out over the water. We could see some passing uh rain bands across South Mississippi on Wednesday going into Thursday, but it looks like the majority of the heavy rain is south of the center out over the water. And you know what?

[00:07:42]That's fine with me. We really don't need any more heavy tropical rains like what we saw with Tropical Storm Arthur.

[00:07:48]This is a little different from Arthur.

[00:07:49]If you remember, Arthur made landfall over in a Texas, but it was moving inland. The The moisture and everything was surging north, and so we were able to pull all that moisture in off of the Gulf. This particular storm is moving parallel to the coast, so it's moving at a completely different trajectory as what Tropical Storm Arthur was moving. So, with this trajectory along or parallel to the coast, we keep the heavy rain out over the water.

[00:08:18]So, that is some good news. With that said, I do think we're going to see some wind with this. I do think we're going to turn breezy. We're going to have an area of low pressure that's going to be tracking really close to us. So, that low pressure is just going to generate some wind along the coast. And because of that wind, there will be sometimes whenever we could look at some higher than normal tides. We're looking at the potential for some storm surge of 2 to 4 ft along the low-lying areas across Hancock, Harrison, and Jackson counties.

[00:08:45]Uh we're looking at high tide on Wednesday being in the morning, and Thursday also being in the morning.

[00:08:52]So, timing will be really important as far as the direction of the wind goes. So, if we have an onshore wind on Wednesday morning, then we could be dealing with flooding Wednesday morning. If we have an offshore wind, we may not be dealing with the flooding Wednesday morning, but by Thursday morning as the center of circulation tracks further west, we could see more flooding. And this is what I mean uh when I'm saying, you know, the direction of the wind is going to play a big role uh on whether or not we see that flooding on Wednesday morning. So, here we fast forward to about Tuesday, Wednesday night.

[00:09:29]That is Wednesday early morning, midnight.

[00:09:34]Notice future cast showing what looks like the center of Bertha.

[00:09:39]Pretty much uh east of Plaquemines or yeah, due east of Plaquemines Parish.

[00:09:43]And so remember, with low pressure you have counterclockwise wind. So on the north side of that low pressure center we're going to have winds predominantly from from east to west. Uh and as we go into the early morning hours, here we are by about 7:00 a.m. on Let's just go back to 6:00.

[00:10:05]So here we are by about 6:00 Wednesday morning. You know, if we start to see this onshore wind start to develop Wednesday morning, we could be dealing with some coastal flooding. Some minor coastal flooding along Hancock, Harrison, Jackson counties.

[00:10:21]Uh those typical low-lying areas that flood when you have an onshore wind or onshore flow. So don't get caught off guard by that. If you live in those low-lying areas where you typically have to go park your car on higher ground because you live in those flood-prone areas where rivers and bayous back up.

[00:10:39]That's the kind of flooding we could see as we go into Wednesday. So uh make some plans, make preparations now if you live in those low-lying areas that typically flood. You know, you don't want your car flooding overnight because the water rises because of the wind pushing the water in. So just keep that in mind. Uh we have lots of areas like that along the coast.

[00:11:00]>> [clears throat] >> Let's fast forward to about midday Wednesday. And again, keep in mind Futurecast is a little bit faster than the official National Hurricane Center forecast track, but just giving you an idea of what the wind could look like.

[00:11:14]Once the center moves to our west, then we start to see more of a southeasterly wind. So that's more of an onshore flow.

[00:11:22]That's whenever our tides could start to be higher. So it could be Wednesday evening into Thursday morning that we see those higher than normal tides and minor coastal flooding because of the winds. And then as we go into Thursday as the area of low pressure gradually pushes away, we start to see the winds go down, but I wouldn't be surprised to see our tides running a little bit higher than normal even into the day on Thursday.

[00:11:48]So, overall, it's not looking like a lot of heavy rain for us if we stay on the north side of the circulation, but we could see some windy conditions on Wednesday going into Thursday that could lead to some minor coastal flooding in some spots.

[00:12:01]Um but of course that's something we want to keep an eye on. Really quickly, just showing you the forecast for tomorrow. Tomorrow's looking like a pretty good day. It's going to be hot.

[00:12:09]Temperatures are going to warm up pretty fast into uh the well, 80s by mid-morning and then by lunchtime, we're looking at uh some low to mid-90s. Wouldn't be surprised to see a few spots get into the upper 90s tomorrow afternoon. Can't rule out a few of those passing rain bands trying to spiral on in tomorrow after afternoon as well. And some of those could produce some gusty winds not to mention some lightning. So, looking at the 7-day forecast as we work our way into uh the rest of the week, just staying weather aware Tuesday, Wednesday, and into Thursday uh as that area of low pressure tracks by. Overall, it doesn't look like a super impactful event, but we're never going to turn our back on a tropical system that's in the Gulf, especially one that is uh this close to the coast.

[00:12:52]And so we'll continue to provide you updates at 10:00. We're going to have uh the updates on our 10:00 newscast as we will have the latest advisory coming in from the National Hurricane Center. Of course, you can download the WLOX First Alert Weather app for the latest information as well.