Eric Berger

This is a fairly long post that we’ve broken into two parts. First up in a look at what to expect for Texas, for the rest of September, when it comes to hurricane season. The TL;DR there is that things look pretty good, but we’ve still got a few weeks to go. The second part of this post was written by Matt Lanza over at our Atlantic hurricanes site, The Eyewall. It offers a broader look at activity so far in the Atlantic basin, and what that may mean for the rest of the season.

Part I: This is absolutely the heart of hurricane season in Texas

Historically, the majority of significant hurricane strikes on Texas have come in September. Most notoriously, there was the 1900 Galveston hurricane, which made landfall on September 8. More recently there was Hurricane Ike, which made landfall on September 13, 2008. This is the time of year when we see tropical waves forming off the coast of Africa, tracking across the Atlantic Ocean, and moving into the Gulf of Mexico. I never schedule vacations in late August and September for the very reason that this is “go” time for big storms.

But as quickly as hurricane season peaks, for Texas it ramps down pretty fast. As I have famously—or infamously, in some quarters—written, the odds of a hurricane strike on the state of Texas really drop precipitously after around September 24. It is too early to say whether that will be the case for this year, but the reality is that we probably have about three or four more weeks of prime time hurricane season in Texas. After that, we should be able to breathe a bit easier.

So what’s on the menu for September 2023?

As per usual, we are seeing large and powerful storms developing in the Atlantic Ocean this year. The good news is that, with the exception of Hurricane Idalia, they have steered away from the Gulf of Mexico. We’ve been heavy on fish storms this year, which is just fine. That’s also likely to be the case with the forthcoming Tropical Storm Lee, which should become a powerful hurricane this week. Read below for more details, but the bottom line is that we expect this one to recurve before nearing the Gulf of Mexico.

Looking out to mid-September, we don’t see any significant threats to the Gulf, or Texas. Not only are there few indications of storms forming or moving into the Gulf, but wind shear levels look high for the next 10 days or even two weeks. This should preclude any significant activity. However, that leaves open a window of opportunity for the last 10 days of September, during which it will be possible for storm activity. The bottom line is that we’re pretty close to the end of the 2023 Texas hurricane season, but we’re not there yet. Given the very warm seas out there, if wind shear drops down, the end of September could be rocking in the Gulf of Mexico.

So we’ll continue watching things for you, and probably post again later next week when we have a bit more insight into the end of the month.

Part II: Taking stock of the 2023 Atlantic season so far

Back in June when we launched The Eyewall, one of the things we did was dive into the components of the seasonal forecast. We explained that the 2023 hurricane season would be trickier than normal, as the developing El Niño, which typically reduces storm activity would be battling an outrageously warm Atlantic Ocean, a feature that would be good for busy storm activity. So far, that battle seems to be exactly what’s playing out. The “consensus” forecast was 16 named storms, 7 hurricanes, and 3 majors. As of Monday, we sat at 12 named storms, 3 hurricanes, and 2 majors.

Our accumulated cyclone energy for the season, or ACE, sits around 125 percent of normal for the first week of September.

If the season ended right now, we would be sitting in the upper tier of “below normal” seasons. In other words, we already have one heck of a base and seem to be on our way to an average season. Idalia, Don, and Franklin, the season’s three hurricanes, account for nearly 75 percent of the seasonal ACE to date. So three legitimate storms make up the majority of the total.

Back in June we said that we believed the Caribbean would struggle (it mostly has), the eastern Atlantic would be busy (it’s been more the central Atlantic, so that point is a little fuzzier), and that the most concerning items this season would be systems forming close to home (Idalia counts for that). So thus far, this is going mostly as expected, if not a little bit busier. Kudos to the seasonal forecasters for not just going all-in on El Niño.

Where are we going?

Well, this week we are likely to see another big jump in seasonal ACE when Lee forms.

From our morning post, you can read how we expect that to become a major hurricane, likely at least a category 4 storm. This will be a big ACE adder, and I suspect we’ll see things shoot up at least into the 70s once Lee is done, pushing us into the “average” tier of seasons if it ended right there. Behind Lee, we may get another storm in the eastern Atlantic, so there’s an opportunity for a few more ACE units.

But here’s something. If you look at the European ensemble model forecast for wind shear in days 11 to 15, which pushes us out to near September 20th now, you can see that the Gulf and western Atlantic are ripping with shear.

If that happens as forecast, anything in the Gulf will struggle, as would anything coming out of the Caribbean. However, the lower wind shear in the eastern Atlantic and central Atlantic suggests these would be the areas where storms could continue to form, continuing the legacy of the 2023 season to date. We may see less hostile conditions return to the Gulf and western Atlantic in the final days of September, but that’s obviously a long way off.

What does El Niño tell us?

Quite frankly, if we assume that El Niño is up and humming now and the influence is strengthening, then we should expect to see a lot of what we’ve already seen for the remainder of hurricane season. Here is a map of all hurricanes in Septembers and Octobers since 1950 when the Oceanic Niño Index (ONI) was 1.0 or greater for June-July-August (this year’s value is 1.1).

With a couple notable exceptions, this map shows a lot of fish storms and middling systems in the western Atlantic. The two most notable exceptions were Joaquin in 2015 which killed 34 people (33 of whom were aboard the El Faro). And also Betsy in 1965, which killed 81 and inundated New Orleans. Emily in 1987 hit Hispaniola and Bermuda. And I think that sums up the season so far: A lot of middling storms and mostly fish storms with one potent hit in Idalia.

All in all, given what we see on the maps right now and given how this season has gone, there are two primary areas that probably should watch for land impacts: Bermuda and the Greater Antilles. If we can relax shear enough late in the season and get a disturbance in the Caribbean that comes straight north, you never know what you can get out of that, and those often threaten Cuba, Jamaica, Hispaniola or the Bahamas. Bermuda remains in the target line I think for at least one or two more storms. Lastly, the eastern Gulf or off the Southeast coast may be secondary areas to watch, given the warm waters and potential for just the right things coming together at the wrong time, sort of like what we saw with Idalia and to a far less impactful extent, Harold in Texas earlier this season.

Will it be enough to drive ACE above normal for the season in the end? I’m not certain, but it will be close.

Good morning. After parts of the Houston region received a decent soaking on Labor Day, the region has one more passable chance of rainfall today before the high heat returns through the weekend. And after that? Well, after that I think we’re done with 100-degree temperatures for awhile, and perhaps even for the entirety of 2023, although I’m not ready to stipulate that yet.

Tuesday

The overall setup today, in terms of rainfall, is similar to Monday. There is plenty of moisture and a decent amount of lift to promote showers and thunderstorms. However, a capping inversion should be a little more pronounced today, and that may limit coverage. The bottom line, I think, is that areas along and east of Interstate 45 probably have about a 50 percent chance of rainfall, and areas to the west about 30 percent.

For the most part these will be quickly passing storms, so don’t expect significant accumulations. Temperatures will depend on the extent of rainfall coverage, but generally we can expect highs to reach the upper 90s with partly to mostly sunny skies. Winds will be light, out of the south. Lows tonight will drop to around 80 degrees.

Wednesday

Skies will be sunny, and most of the area will see temperatures of around 100 degrees. Rain chances aren’t going away entirely, but we’re looking at chances probably on the order of 10 to 20 percent. Winds will be light, out of the southeast.

Thursday and Friday

Who is ready for the return of the ridge? The answer, I realize, is almost no one. But high pressure will indeed build back over the are during the end of the week. This will produce highs of around 100 to the low 100s. This won’t quit be the stultifying heat we saw earlier this summer, but it’s still going to be really, really hot.

Saturday and Sunday

The heat continues, with highs of around 100 degrees each day. However as the high pressure system eases westward it will introduce some slight rain chances, perhaps 20 percent, each day. Skies, for the most part, should be sunny however.

Next week

Hey Eric, didn’t you mention the “end of the worst summer ever” in the post’s title? Well, yes I did. And it wasn’t clickbait, I promise. The reality is that after the surge of heat to end this week, our pattern should shift to a slightly more moderate one that will feel a bit more like late summer. That is to say, for most of next week, we probably will see highs top out in the mid-90s—or even lower if we see the development of some afternoon showers. Which will be possible. The bottom line is that we’re probably looking at a little bit less sunshine, a little bit less heat, and possibly a little bit more rainfall. It’s not fall, but after this week, I think we can close the door on extreme heat for the summer of 2023. Small victories, right?

Hurricane season

Check back on the site around 10 am for a post on what to expect for the remainder of the Atlantic hurricane season, with a focus on Texas.

Good morning and happy Labor Day. In honor of the holiday, this will be a fairly short post. After slight rain chances on Saturday and Sunday fizzled out, today offers our best hope of meaningful since July. The setup is pretty good, with the combination of ample moisture, daytime heating, and a fair amount of instability in the atmosphere. This is all being driven by an upper-level low pressure system to the north of our region.

As of 7:30 am CT, we are already seeing numerous showers just to the east of our region, from Bolivar Peninsula over to Lake Charles, Louisiana. Over the next few hours, these showers should build westward, closer to the Houston area. But that is not a guarantee you will see rainfall. I would say that areas to the east of Interstate 45 have about a 60 percent chance of seeing showers or thunderstorms today, with areas to the west 40 percent or perhaps even less, especially areas further inland.

Rainfall amounts will vary widely. A few lucky locations may pick up 1 inch of rain or more, but for the most part it should be measured in a few tenths of an inch. Of course many locations will not see any rain. Storms that do form, generally, will move from south to north.

Highs today will depend on the extent of rainfall and cloud cover this afternoon. Areas east of Interstate 45 may max out in the lower 90s, whereas areas further west may reach the upper 90s.

I expect that Tuesday will be similar, in terms of the setup, although I would expect slightly less storm coverage during the afternoon hours. Wednesday, too, will carry at least a 20 or 30 percent chance of showers.

The period of Thursday through Sunday quite hot again, as high pressure builds over the region. We’ll probably see highs in the upper 90s, with mostly sunny skies. Some areas may very well reach 100 degrees again. I am cautiously optimistic that this period, Thursday through Sunday, may be our last real fling of triple digit weather for 2023. No guarantees, but after that the temperature outlook does start to look a bit better.

We’ll be back tomorrow with a full forecast. Please enjoy your holiday safely, responsibly, and, if you’re lucky, with a measure of liquid gold from the skies.

According to data from the National Weather Service, the month of August finished with an extraordinary average temperature of 91.0 degrees. This is nearly 6 degrees higher than the “normal” average temperature for the month of August in Houston, 85.2 degrees.

Moreover, it exceeded the city’s warmest month on record—any month in the last 150 years, mind you. This previous record temperature. 90.4 degrees, was set during the absolutely torrid month of August 2011. Temperatures this August were, by any measure, extreme and not-normal. The brown area in the graphic below shows the normal range of temperatures.

Along with this extreme heat, we recorded just 0.01 inch of rain during the month of August at the city’s official station, at Bush Intercontinental Airport. That’s one-hundredth of an inch. This was less rain than even the 0.09 inches recorded in August 2011, but second driest on record to a “trace” of rainfall recorded in 1927. The good news is that while our heat will continue, albeit at not as crazy levels, we do have some improving rain chances in the days ahead.

Friday

It’s not going to rain today, as we’re still under the influence of a weak front. This means we’re going to see sunny skies, with highs of around 100 degrees for much of the area. But we’re still enjoying some lower humidity this morning, and that should carry into the afternoon hours. However as light northeasterly winds turn easterly, humidity levels will rise. Lows tonight should drop into the upper 70s.

Saturday

This will be a sunny, hot, and somewhat humid day with highs near 100 degrees for the area. As moisture levels rise we’ll see an increasing chance of showers and thunderstorms near the coast. I’d say areas along and south of Interstate 10 have about a one-in-three chance of seeing a passing shower on Saturday. Skies will be mostly sunny, otherwise. Lows on Saturday night may briefly drop below 80 degrees.

Sunday and Labor Day

Here’s where the rain chances peak. Rainfall odds for much of the area are probably about 50 percent on Sunday, and 70 percent on Labor Day. Again, when it’s not raining (which should be most of the time), skies are going to be mostly sunny. So these will be passing showers as an upper-level low pressure system over Louisiana perturbs our atmosphere. The further one lives away from the coast, and the further west, the lower the rain chances and accumulations. So while I think coastal areas may end up with accumulations of about 0.5 inch, most areas further inland probably will receive less. Temperatures both days should be in the mid- to upper-90s, and moderated of course by passing showers.

Next week

Tuesday and Wednesday will both have a decent chance of rain showers, perhaps 40 percent each day, but then we’re probably going back to the upper 90s for the second half of next week with a hot and mostly rain-free pattern. We’ll probably remain mostly that way through the middle of September.

We’ll have an update for you on Labor Day morning about the area’s rain chances. Have a wonderful holiday weekend.