In brief: Houston will see another warm and humid day, but there will be a twist this afternoon as a broken line of showers and thunderstorms pushes through the area from northwest to southeast. Drier air will follow overnight, leading to sunny days with lower humidity. It’s a weak front, but in September, who’s complaining?

Wednesday

Most of the area will be warm and humid again today, with high temperatures in the low-90s. Skies will be mostly sunny this morning, but then we should see some clouds building up this afternoon with increasing levels of moisture in the atmosphere. By later this afternoon we should see a broken line of showers, perhaps with a few embedded thunderstorms, moving from northwest to southeast across the area. This line should reach from Sugar Land to downtown Houston to Kingwood by around 4 to 6 pm, and push down to the coast by around 7 to 9 pm.

As it nears the coast, this boundary should gradually run into more moisture, and this could help fill in the gaps. There is a slight threat of some briefly damaging winds in any of the stronger thunderstorms that develop. Unfortunately, I don’t think the frontal passage is going to bring widespread, drenching rains, which the area needs after a fairly dry September. Some locations may pick up 0.5 inch of rain, but most of the region, and especially areas inland of Interstate 10, are likely to see little to no rain. Lows tonight will drop to around 70 degrees.

Thursday and Friday

Drier air starts to filter in overnight, and we’ll see a couple of slightly cooler days. High temperatures on Thursday and Friday will reach the upper-80s, with lots of sunshine. Thursday may be a bit gusty in terms of northerly winds, but these will settle down somewhat by Thursday night. Lows, for the most part, will reach the upper 60s in the Houston area and drop down a little further outside of the city and away from the coast. Mornings and evenings will feel lovely.

Saturday and Sunday

Sunny weather continues, with daytime highs in the low 90s and nighttime lows around 70 degrees. The humidity will recover some, but not get back to really sticky dewpoints. So again, mornings and evenings will be fairly pleasant outside.

Next week

Expect more sunshine and highs in the low-90s. There is some support for a front arriving by Thursday or Friday of next week, but it is far from universal in the weather model ensembles. What does seem clear is that, after today, rain chances are very low for awhile for our area. That’s one reason why I’m hoping for today’s showers to overperform expectations.

Tropics

Now entering the Gulf of Mexico, Tropical Storm Helene is approaching hurricane strength with 70-mph sustained winds. It is expected to become a powerful Category 3 hurricane before striking the northwest Florida coast on Thursday evening. This storm will have widespread, myriad effects. We’ll have continuing coverage today on The Eyewall.

In brief: In today’s post we share our annual message about the Texas hurricane season likely being over for the rest of the year. This means we are fairly confident that a hurricane is not going to strike Texas for the remainder of 2024. Additionally, we look ahead to a short but sweet front that arrives on Wednesday. Dry air? Is such a thing even possible in Houston?

Tropics season is winding down

I’ll let you in on a little secret. Every September, around this time of year, I’ll write a post that essentially says the Texas hurricane season is over. And every time, my wife hates it. Why? Because there’s a non-zero chance that I am wrong and that, despite the odds, a hurricane will actually strike the Texas coast during the remainder of the season. It would be pretty embarrassing.

But I believe in reporting and writing what I honestly think is true. And I’m here to tell you, both Matt and I think the likelihood of a hurricane striking Texas after today this year is pretty darn low. Historically, the odds are about 1-in-50. Looking at the available data for this year, there are a couple of things to consider. Yes, the Gulf of Mexico is historically warm, and such sea surface temperatures tend to support the idea that we could see tropical systems blow up into hurricanes.

However, there are solid reasons to believe that we’re done for this year beyond the historical odds. First of all, after soon-to-form Tropical Storm Helene, the Gulf of Mexico looks fairly quiet over the next week, if not longer. That gets us into October. Then there is the overall pattern change to consider. We’ve already had one cool front earlier this month. Another is on the way Wednesday. Quite possibly, we’ll get a third front some time next week. When you start to see this kind of fall-like pattern of regular fronts, it becomes very difficult for a hurricane to blaze a trail westward across the Gulf of Mexico into Texas. Not impossible, mind you, but very unlikely.

None of this means that we won’t see tropical weather in October, or possibly even November. We could see tropical lows bringing heavy rainfall for many weeks to come. But the odds of another hurricane bearing down on our region are pretty darn low at this point. If you want to breathe a little easier, that’s fine with us.

We’ll continue to monitor the tropics, of course, and if there’s anything threatening we’ll definitely call attention to it. The Atlantic hurricane season is very much not over for the rest of the basin, particularly Florida and the Caribbean Islands. Their season lasts into November.

Tuesday

Monday’s high temperature was 95 degrees at Bush Intercontinental Airport, but I think we’re finally done with the mid-90s. Next week could see a few pretty warm days, but the worst of this late summer fling we’ve been experiencing this month should finally be at an end. Highs today will be closer to 90 degrees as we see more clouds, and some elevated rain chances. Expect to see a couple of impulses moving through the area from northwest to southeast, each bringing some scattered showers. Rain chances will be about 40 percent today, and continuing into tonight. Overnight lows will drop into the mid-70s for most locations.

Wednesday

The front will sag into the Houston area throughout the day on Wednesday, likely not reaching areas south of the city until Wednesday night. Therefore, most of the region is likely to reach about 90 degrees, with a mix of sunshine and clouds. As the front gets closer to the coast it will tap into more moisture, so I expect to see a decent amount of showers south of Interstate 10 on Wednesday evening as the front pushes down to the coast. Lows on Wednesday night will drop to about 70 degrees in Houston, with cooler temperatures in outlying areas.

Thursday and Friday

These will be a pair of warm days, with highs generally in the upper 80s, and sunny skies. With dewpoints in the 50s, the air will feel noticeably drier. Lows on Thursday and Friday nights will drop into the 60s away from the coast. This is a weak front, so its effects will be modest and won’t last all that long—nevertheless mornings and evenings will be pleasant so plan to spend a little time outside enjoying the fleetingly drier air.

Saturday and Sunday

Highs will get back to about 90 degrees on Saturday, and into the lower 90s by Sunday, under mostly sunny skies. Humidity will rebound some, but with dewpoints in the 60s it’s not going to be the full-on humidity that Houston is known for in the summer. Rain chances are near zero.

Next week

We’ll be in the low 90s to start next week with plenty of sunshine. Humidity levels should remain marginally lower than ‘normal’ for summer, so that will be nice, and should allow overnight lows to continue dropping to around 70 degrees. There’s some hint of a cool front in about the Wednesday or Thursday time frame, but it’s no sure thing it pushes all the way down to the coast. We shall see.

In brief: After an extremely warm spell over the last 10 days, some relief arrives this week in the form of a decent front (for September). Helpfully, we’ll also see some rain chances on the rise, although we’re not going to see inches of precipitation. The weekend looks sunny and warm.

Beginning to transition to fall

Houston’s streak of days with temperatures above 95 degrees continued through the weekend as our region’s anomalously warm pattern continued. We may get day number 10 today. However, some relief really is on the way the a cool front arriving on Wednesday, with some decent rain chances, and then cooler weather for the rest of the week. It’s still September, so don’t expect miracles. But daytime highs in the 80s and drier air will make for a nice pattern change for a few days. Another front is possible during the first week of October—so while it won’t feel cool and crisp like fall, we’re definitely entering a pattern during which we’re beginning to transition to fall.

Monday and Tuesday

For the next two days we’re going to be stuck in the cool front waiting room. Highs for most locations should top out in the lower-90s, but some inland locations could reach the mid-90s again. Skies will be mostly sunny. What will change is that increasing atmospheric moisture levels will lead to some decent rain chances. Overall odds will be best for coastal locations, perhaps as high as 50 percent on Tuesday. The likelihood of rain will be lesser for areas further inland.

Wednesday

Some time on Wednesday we should see a line of showers, possibly broken, heralding the arrival of a front. Highs on Wednesday will likely still reach about 90 degrees, with sunny skies following the front’s arrival. Lows on Wednesday night will drop to around 70 degrees in Houston.

Thursday and Friday

These will be a pair of days with high temperatures likely in the mid- to upper-80s for most locations, with sunny skies. Winds from the north will knock dewpoints into the 50s, which will mean the air feels much drier and the mornings and evenings will be quite pleasant. Low temperatures will fall into the mid- to upper-60s for most locations. This is the way of these September fronts—they tease us with fall, they never last long, but after a long summer even a modest change feels great.

Saturday and Sunday

The weekend should be warm and mostly sunny, with rising humidity. I cannot rule out some rain chances, but I’d put them at 10 percent or less, so probably not impactful. Highs will be around 90 degrees on Saturday, and perhaps a tick warmer on Sunday.

Next week

We are likely going back into the low-90s, with sunny skies, for the first half of next week. However, there is a decent amount of support for another front by next Wednesday or Thursday. Please just pencil this one in, however, as it’s still not a sure thing.

Tropics

A tropical system is likely to move into the Gulf of Mexico on Wednesday, and it may strike Florida by as early as Thursday evening. It poses no threat to Texas. However, I am increasingly concerned about this becoming a powerful hurricane in the very warm eastern Gulf of Mexico. We’ll have continuing coverage of its development and impacts on The Eyewall.

As for what’s next for Texas and the tropics, be sure and check Space City Weather tomorrow for an update on that.

In brief: Although a tropical system that will develop in the Gulf of Mexico this week poses no threat to Texas, we’ve been receiving a lot of questions about it on Space City Weather. So we’re sharing this update from The Eyewall in order to tell Texas readers they have nothing to worry about. It’s likely a different story for Florida, however.

The state of the tropical system

We’ve been talking about the potential for a tropical storm to form in the northwest Caribbean Sea for days, and for the time being there’s still not much to look at on satellite. We’re still seeing disorganized showers and thunderstorms in the western Caribbean Sea, in the vicinity of Nicaragua. However, what has changed is that the models we trust the most are now pointing to a more or less similar outcome over the coming week. That is, we expect a tropical system to develop, and then move into the southeastern Gulf of Mexico by around Wednesday. And after that? Well, that’s what the rest of this post will discuss.

Track of the storm

All of our major model guidance now suggests that a tropical system will start to become better organized by Tuesday or Wednesday, with a center of low pressure forming near Cancun, Mexico, or the western tip of the island of Cuba. There is still some discrepancy in the timing and intensity, but we can have pretty high confidence in this outcome.

The timing of this does matter, as a more rapidly developing storm would likely ultimately track further to the east, which is to say toward the west coast of Florida; and a slower developing system has a better chance of going more due north, ultimately making landfall somewhere between the Louisiana delta and Florida panhandle.

If we look at the 06z run of the European ensemble model above, we can get a sense of the most likely locations where the center of this storm could go. Note that this forecast indicates a potential landfall on Friday, but depending on the forward speed of this system, we cannot rule out a tropical storm or hurricane reaching the coast as early as Thursday.

The other global model ensembles are not dissimilar to the European model shown above. Our best high resolution, operational models are starting to coalesce around a landfall somewhere between Destin, Florida, and Cedar Key, Florida. However given that a center of circulation has not formed, overall confidence in where precisely this storm will go about five days from now is necessarily low.

The most important message I want to leave readers with today is that residents of the Gulf coast from southeastern Louisiana all the way to Fort Myers, Florida, should be keeping tabs on this system over the next couple of days.

As a space guy, I’m also watching closely for impacts to NASA’s Crew-9 launch from Cape Canaveral, Florida, presently scheduled for Thursday afternoon.

What about its intensity?

Forecasting the intensity of a tropical system, of course, often more dicey than a track forecast. Because the storm has not been designated an “area of investigation,” or Invest, we do not have access to a suite of tropical-based models that are used to forecast intensity. So far the global models have been all over the place, ranging from tropical storms to a fairly powerful hurricane. However, these models typically do a poor job with intensity.

From a big picture standpoint, what concerns us here at The Eyewall is that there are no obvious things to slow this storm down. If it does start to develop a low pressure center by around Tuesday or Wednesday, then it would have two full days over the Eastern Gulf of Mexico to intensify, and if conditions are right that offers plenty of time to blow up into a powerful hurricane.

The sea surface temperatures in the vicinity of where this system should track are incredibly warm. This is partly because it is late September, and partly because of the background signal of climate change that has pushed oceanic temperatures, generally, to record highs. In addition, when we look at conditions beneath the surface, oceanic heat content is very high. This means that, as a storm churns north across the Gulf of Mexico, it will not necessarily be bringing cooler water to the surface. Deep oceanic heat is often a precursor to rapid intensification.

Wind shear has been fairly high over the eastern Gulf of Mexico over the last several days, but this shear level is now trending lower. And if this pattern continues as expected, the environment for storm formation and strengthening should be neutral in terms of wind shear, if not even favorable. So we cannot really count on shear for assistance.

Perhaps dry air, particularly on the western flank of the storm, may play a role in inhibiting some development. However, when we stack up the extremely warm surface temperatures in the eastern Gulf of Mexico, and the shear environment, I have to believe that a hurricane is likely to form before landfall late this week. This is another reason for residents of the northern Gulf of Mexico and Florida to keep a close tab on things.

Some final thoughts

It’s still too early to say too much about impacts from this system. However, storm surge, wind damage, and inland flooding from rainfall are all on the table. Where these occur, of course, remains highly dependent upon the track.

Given the current trends, it is unlikely that we see a named storm develop before Tuesday or Wednesday. Waiting for a named storm, therefore, will not leave much time for preparation. Again, this is why we’re advising residents to keep a close eye on things over the next couple of days.