Matt Lanza

Tropical Storm Edouard begins its final approach toward the Texas-Louisiana border

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In brief: Tropical Storm Edouard has about 8 to 12 hours left over water to intensify, and it will make an effort to do so. But it will run out of time later, bringing some gusty winds, surge, and heavy rain to parts of Louisiana and Texas. We discuss the situation in detail below.

The good news is that Edouard managed to make it through the night without intensifying much. In fact, maximum sustained winds this morning remain around 40 mph. The less good news is that “under the hood,” Edouard seems poised to try and make a go at intensifying a bit before it makes landfall in about 8 to 12 hours from this writing. Basically, Edouard has what it needs to try and intensify quickly up to landfall but whether its able to put all those things together is an open question and the difference between a sloppy 40 mph tropical storm making landfall and a compact 60 to 70 mph tropical storm making landfall.

Edouard is trying to wrap some stronger thunderstorms near the center, usually a sign the storm is trying to intensify. (WeatherFront)

The NHC has taken that latter scenario and applied it to Edouard’s forecast, bringing ashore a 65 mph tropical storm near Sabine Pass later today. The environment around Edouard, other than proximity to land is as optimal as you really need for intensification. I saw a post on social media yesterday from someone that said essentially, “I suspect we’re going to see a lot of ‘good thing this didn’t have 24 more hours over water’ posts tomorrow.” I forget who posted it, but it seems spot on. The biggest limiting factor to Edouard today will be that it has less than 12 more hours over water.

In terms of impacts, Edouard will make landfall sometime this afternoon, likely within 10 miles or so of Sabine Pass, TX. Recall yesterday that we said Edouard’s wind field was likely to be compact when it began intensifying, no more than 30 miles or so across. The current wind radius on Edouard is 25 miles from the center. This means that any wind impacts from Edouard will be very isolated to near where the center comes ashore. The best chance of wind gusts officially reaching tropical storm intensity will be between Cameron, LA and just west of Sabine Pass, perhaps to High Island.

HAFS-B model forecast of Edouard’s wind gusts near landfall, showing a tight, compact area of stronger tropical storm force wind gusts isolated to within 20 to 30 miles of the center. (WeatherFront)

Edouard is going to weaken quickly once inland, and by the time it reaches I-10, it will probably barely be able to hold together tropical storm force wind gusts.

Edouard’s winds should be mostly below tropical storm intensity when it gets to Liberty, Hardin, and Chambers Counties east of Houston. (WeatherFront)

Some residual gusts to tropical storm strength are possible east of Houston, across Liberty, northern Chambers, or Hardin Counties but that would be about it. It seems highly unlikely that Houston itself will see tropical storm conditions at any point.

Obviously, the rain will be another story. It continues to appear that any real flash flooding risk is east of Houston today and tonight. Locally heavy rain may occur across Liberty, Chambers, Hardin, and Jefferson Counties in Southeast Texas and in Calcasieu and Cameron Parishes in Louisiana.

Forecast rain from the REFS ensemble through midday Wednesday. Some areas will see less than shown here. (WeatherFront)

Rain totals are taken from the REFS ensemble system above, and they may be a bit aggressive east of Houston. But you get the idea: 3 to 6 inches of rain in a narrow corridor between Houston and Beaumont.

This is somewhat speculative on my part, but the remnant center of Edouard should be in the Brazos Valley tonight, near Huntsville or Madisonville. We sometimes see the centers of these things try to pop up more numerous thunderstorms than forecast during the diurnal peak in convection overnight (the propensity for tropical systems to peak their thunderstorm activity in the overnight hours). There could be a localized flooding threat somewhere up near Huntsville, Madisonville, or Centerville overnight, so just be aware of that. A flood watch is posted over a wide area of Texas today.

The good news is that a lot of places are rather dry right now, so the rain should be soaked up in a lot of cases. Obviously, you never want too much too fast. But the hope is that this will limit serious flooding.

Last point here, storm surge flooding should impact travel on Gulf Beach Highway in Louisiana through the day today, with up to 5 feet of surge possible near and east of where Edouard comes ashore.

Peak surge forecast potential from Edouard. (NOAA NHC)

Follow Space City Weather for the latest details on Edouard around the Houston area.

Tropical Depression 5 on the way to becoming Edouard and impacting Texas & Louisiana as a feisty little storm

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In brief: We take a big picture look at what will push Tropical Depression 5 likely into Tropical Storm Edouard later tonight, as well as what will impact its intensity going into tomorrow. We talk about the wind potential on the coast and the flooding potential inland.

Over at Space City Weather, Eric takes a look at how TD 5, or what should become Edouard will impact the Houston area. My purpose here is to zoom out a little and take a look at TD 5 from a larger perspective.

First, as of this evening, the storm center of Tropical Depression 5 is located south of Vermilion Bay, Louisiana. Maximum sustained winds are 35 mph, so we’re not yet at tropical storm intensity.

Tropical Depression 5 over the northwest Gulf on Monday evening just after 4 PM CT. (WeatherFront)

There has been hurricane hunter activity in the depression throughout the day, and the read is that the circulation is becoming better defined. They’ll be back out tonight, and given how things have gone today, I would not be the least bit shocked to see this upgraded to a named storm with the 10 PM CT advisory.

The track forecast for TD 5 is actually relatively straightforward and simple. It will continue west northwest to northwest and make landfall somewhere between High Island, TX and Cameron Parish, LA tomorrow afternoon or evening.

Other than a few outliers, the Google Deep Mind 1,000 member ensemble is in strong agreement on a landfall between High Island and Cameron, LA. (tcatlas.org)

TD 5 has about 24 hours over water to do whatever it will do.

So, what will it do? Normally, we’d look at a system like this and say, “Ok, weak to maybe moderate tropical storm, and that’s that.” TD 5 is slightly different. It’s small, it’s healthy “under the hood,” and it’s over very warm water in an extremely low shear environment. The key in that sentence is that it’s small. Small storms deserve love too. And in fact, sometimes these smaller storms can thrive in this part of the world, easier to wind up. And with only 24 hours over water, this storm will probably come ashore while intensifying, meaning it may punch a little above its weight class in terms of coastal impacts.

The latest NHC forecast brings TD 5 to 60 mph at landfall near Sabine Pass, TX. About 20 percent of Google 1,000 member ensemble members bring TD 5 above 60 mph at landfall, with about 5 to 10 percent doing so as a hurricane. Google’s operational WN2 model is not as excited with this, but I think this is an excellent use case for a 1,000 member ensemble. It gives you a more adequate dispersion of members in terms of intensity, and with small storms that can easily fluctuate like this one should, that’s helpful.

Let’s talk about the potential of a higher-end outcome. Let’s say TD 5 becomes a hurricane. Heck, even just a strong tropical storm. What sort of wind would we be looking at here? The answer is “a very compact, localized” wind field that would quickly drop off as it moved inland.

The wind field of stronger wind gusts from TD 5/Edouard should only be about 30 miles or so wide, and it will likely drop off significantly once inland. (WeatherFront)

In this scenario, you’d have strong tropical storm or hurricane-force gusts on the immediate coast between High Island, TX and about Johnson Bayou, LA. And the western flank of that may even be a little generous. By the time you got to Winnie, Nederland, Beaumont, Orange, Vinton, or Sulphur along I-10, you’d be talking about low-end tropical storm force wind gusts. At best. The storm would weaken rather fast once onshore, and this would likely substantially crush the wind intensity. In fact, if you run the HWRF, shown here, out 3 hours from here, you get max wind gusts in the 40s south of I-10 and 30s north of I-10.

Also, notable since the broader media will tie this into “Greater Houston,” this outcome would keep tropical storm force winds away from the entirety of the Houston Metro area, except maybe, maybe Galveston and Bolivar.

So, if you live on the coast or just inland between High Island and Johnson Bayou, I encourage you to prepare as if a strong tropical storm or Category 1 hurricane were coming.

In terms of rain, the good news is that the system looks generally progressive. The remnant center of it should be somewhere south of Dallas or east of Temple by Wednesday afternoon. But, the system is rather moisture-laden, so it will be able to dump some hefty rain near where the center tracks. In general, I would expect about 1 to 3 inches of rain east of I-45 with a band of 3 to 7 inch totals along the center track. That’s what should track through western Jefferson, eastern Chambers, Liberty, Hardin, Tyler, Polk, and San Jacinto Counties. Within that 3 to 7 inch corridor, there could be a bullseye closer to 10 inches in one or two spots.

The heaviest rain from TD 5 will likely fall east of the Houston Metro and west of Beaumont. (Pivotal Weather)

In the Houston Metro, we cover that at Space City Weather, but there is likely to be a very sharp gradient where parts of the area see nothing at all, up to an inch, then a quick escalation to 3, 4, 5 inches or more somewhere east of I-45. For Beaumont-Port Arthur, this looks like the heaviest rain will fall south and west of those cities, but it’s possible we see over 3 inches in spots. An inch or so is possible in Lake Charles, as well as around the periphery of where TD 5/Edouard “dies” in Texas, be it near Waco or Lufkin.

While this is probably not a severe flooding risk, there will be pockets of flash flooding possible later tomorrow through Wednesday morning, so just be advised of that in those areas.

We’ll update the situation again in the morning. Stay safe!

Invest 97L, yet to organize, looks to dump some heavy rain east of Houston and west of Beaumont this week

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In brief: Invest 97L has an imposing satellite image but it has yet to make serious strides toward actually organizing yet. It remains distinctly a heavy rain and flash flooding concern, particularly east of Houston heading into midweek. But folks close to the coast east of Houston should continue to monitor Invest 97L for potential development before it comes ashore tomorrow.

Invest 97L

The good news is that scary looking satellite imagery is not correlated to tropical system intensity. On satellite, Invest 97L looks quite imposing this morning, but it’s notable that almost all the storminess is to the east of the presumed center.

Invest 97L has an imposing look on satellite this morning (WeatherFront)

Aside from that, we remain around 70 percent odds of potential development as of the overnight update from NHC. In terms of things that have and have not changed otherwise overnight: The track is mostly unchanged, generally toward the Upper Texas Coast with the center arriving onshore sometime tomorrow afternoon or evening. If there is a slight change in track, it’s that more tropical models are a little farther south and west with 97L, perhaps owing to the fact that it has not developed yet.

Tropical modeling brings the center a little closer to Bolivar than High Island or Port Arthur, partially due to the fact that it has not organized yet. (Tropical Tidbits)

Weaker systems will tend to go a little farther west before turning northward, and that could be what’s at play here. Either way, it’s good news that it has not organized yet. The more time it takes organizing also reduces the amount of time it has to intensify. So in general, we’re still looking at a decent chance at a tropical depression and a moderate chance at a tropical storm by landfall. People on the Texas coast, especially east of Houston should continue to monitor Invest 97L through the day.

What we are likely to see is more rain, however. Rain totals continue to slowly increase in East Texas. We would now expect about 1 to 3 inches, with isolated pockets of 3-5 inches of rain or more east of Houston and west of Beaumont. It’s not out of the question that someone sees close to 10 inches of rain from this before all is said and done, so obviously areas of flash flooding will be a concern, perhaps not in Houston proper, but east of there.

Total rainfall from 97L will likely exceed 5 inches in spots east of Houston and west of Beaumont. (WeatherFront)

So, bottom line? A tropical storm remains a distinct possibility out of Invest 97L. A depression is a good bet. The main threat will be heavy rain and flooding between Houston and Beaumont and inland from there. But folks east of Houston, between Bolivar and Port Arthur will want to keep an eye on 97L over the next 36 hours before landfall, in case it does try to organize faster.

More later today.

Invest 97L inching closer to something more formal Sunday evening

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In brief: Invest 97L continues to hold its own in the Gulf, with some further increasing potential that it may develop into a depression or named storm before coming ashore in Texas or Louisiana on Tuesday. The heavy rainfall threat, especially north of Houston and east of I-35 seems to also be increasing some.

This post will be fairly brief, but I wanted to add some thoughts regarding Invest 97L before the morning. First off, it looks mostly the same this evening as it did earlier today, which is a bit of a small feat in and of itself, as typically these nascent systems strengthen more overnight and weaken during the day. That it has held its own indicates it’s probably in shape to organize a bit further.

Invest 97L is holding its own this evening south of Louisiana. (WeatherFront)

What has changed as a result of this and recent model guidance is two-fold. First, a bigger risk of locally heavy rain in Texas and Louisiana. Second, a higher chance that 97L will actually develop into a depression or storm. The NHC has raised odds to 70% this evening, but I would think the odds are closer to 90% for a depression and 60 to 70 percent for a named storm. Either way, they are now higher.

Modeling is in good agreement on both track and timing of the system, giving it about 36 or so more hours over water before making landfall near Port Arthur or High Island, TX sometime during the second half of the day Tuesday. Models have become a bit more scattered in terms of intensity of 97L today, with a few more pulsing up into tropical storm status.

Invest 97L has limited time over water, but it may try to make the most of what it does have to become a depression or named storm. (Polarwx.com)

At this point, if you live on the Upper Texas Coast east of Baytown through about Cameron Parish, LA, it makes sense to prepare for a tropical storm. This means the potential for heavy rain, gusty winds, some minor to moderate coastal flooding, and rough seas. The problem with these smaller systems like 97L is that they don’t give you a whole lot of warning and then all of a sudden they ramp up. Think of Hurricane Humberto in 2007 as a prime example of this. It wound up from a disturbance to a small hurricane in about 24 hours. The initial forecast from the NHC for Humberto had max winds of 45 mph. I’m not saying Invest 97L will do that; our modeling has improved quite a lot in 20 years. But I am saying that model guidance still doesn’t always capture these smaller storms properly, and it’s better to err on the side of caution in these areas, especially to the east side of where the storm may come ashore.

Updated NBM forecast rainfall over the next several days. (WeatherFront)

I am growing a little more interested and potentially concerned about the potential for flash flooding in parts of Texas from 97L, especially north of Houston and east of I-35. Rain totals have trended up a good bit since earlier today, and I think the potential exists for rain totals to increase more over the next couple days. I’d watch the triangle between Beaumont, College Station, and Lufkin closest right now, but let’s see how things play out over the next couple days.

More in the AM.