Good morning. In the big picture, Houston’s overall forecast remains largely the same. After some lovely, drier air we’re back into high humidity and high heat through the weekend. By Monday, we’ll be watching the Gulf of Mexico with bated breath, to see whether a tropical system brings much needed rainfall to the Upper Texas coast. I think that’s still about a 50-50 proposition.

Before jumping into the forecast I want to answer a question I’ve received many times in recent weeks about this summer, which has seen record temperatures in the Gulf of Mexico, alarmingly low levels of sea ice, and extreme heat around much of the world. NASA recently concluded that July 2023 is the planet’s hottest month in the reliable global temperature record, which dates back to 1880. The question I’m getting is, could this be caused by the large amount of water vapor injected into the upper atmosphere by the eruption of the Hunga Tonga volcano in December 2021, in the Southern Pacific Ocean?

Typically, big volcanic eruptions send large amounts of sulfur dioxide into the stratosphere, which reflects sunlight and cools the climate. By contrast, the Hunga Tonga eruption also produced large amounts of water vapor, a potent greenhouse gas. So is this the culprit for extremely warm temperatures this year?

As always with climate, the answer is complex, and nuanced. However, the Berkeley Earth non-governmental organization recently published an analysis that I think captures several of the factors that led to this summer’s heating. Principally, there is human-caused global warming; but there are a number of other factors that have contributed this year, including a switch to El Niño, the Solar cycle, the Hunga Tonga eruption, and a reduction in marine fuel pollution that has led to clearer air. All of these factors, layered on top of global warming, have really goosed temperatures this year.

As the report notes, the effect of the Hunga Tonga eruption is probably relatively small, but it likely has added some warmth to the planet after injecting about 150 million tonnes of water vapor into the stratosphere. It will take a few years for this plume to dissipate. Please note that I realize that the mere mention of climate change gets some readers really upset. I’m sorry, but on a weather website it is occasionally necessary to mention that the planet is warming, and discuss potential causes. If you feel compelled to get nasty in the comments below, your IP address will be banned. Most readers have been polite in previous discussions, agreeing to disagree, and I appreciate that.

Now, on to the forecast.

Thursday

The dry air, sadly, is gone. And so we welcome back high temperatures in the low 100s, humid air, sunny skies, and light southerly winds. Nighttime lows are around 80 degrees. We all know the drill.

Friday

More of the same.

Saturday and Sunday

The weekend looks sunny and hot, with high temperatures again of around 100 degrees, or perhaps a tick or two higher. There’s a slight chance of some rain on Sunday afternoon, but I wouldn’t hold your breath.

Next week

So what’s going to happen next week with that tropical wave? Unfortunately the global models remain divided about its outcome. The Global Forecast System, or GFS model, keeps the low to the south of the greater Houston area, along with much of its rainfall. The European model, however, brings the low much closer to our region, and delivers a healthy dose of rainfall during the middle of next week. I think both scenarios are plausible, so I don’t have confidence in making a forecast just yet. If we do get some cloudy, rainy days, it will knock high temperatures back into the 90s. Please clap.

I don’t want anyone to get the wrong idea. In the big picture, the remainder of August looks very hot. There is just no way to sugarcoat that. However, there are some subtleties in the forecast to keep things interesting, including modestly low humidity today, and a tropical wave in the Gulf of Mexico next week. We’ll discuss all of that below.

Wednesday

A weak front has pushed very nearly all the way to the coast this morning. As we’ve been discussing, this is not an October cool front, so at most we’re seeing some dry air. But as Augusts go, it’s rather nice outside this morning. Much of the area is seeing temperatures in the 70s, with dewpoints in the 50s. This kind of weather isn’t coming back any time soon, so I’d recommend stepping outside to avail yourself of it.

This modestly drier air, alas, will also heat up rather quickly. So even though we’re experiencing a front, most of the area will still reach the upper 90s to lower 100s today. Still, I invite you to walk around and say, “At least it’s a dry heat,” to your friends because we simply don’t get to do that too often in Houston. As for the lower humidity, it will largely be gone by this evening for the southern half of the metro area, and overnight for everyone. So get outside this morning.

Thursday and Friday

I’m afraid we’re going right back to high humidity, daytime highs in the low 100s, sunny skies, and rain chances of about 5 percent or less. So basically, like the weather of August to date.

Saturday and Sunday

The weekend should bring more of the same, with hot weather and mostly sunny skies. If I squint, there might be some 10 to 20 percent rain chances on the horizon for Sunday.

Next week

Well, it’s complicated. We’re still anticipating a tropical wave to develop in the central Gulf of Mexico early next week, and then move westward. Since writing about this, several readers have expressed concern about this wave developing into a hurricane, but there are a lot of reasons why that is unlikely to happen, among them a fairly high forward speed. The National Hurricane Center suggests there is about a 20 percent chance the system becomes a tropical depression over the next seven days, and that feels about right to me. So while we’ll keep track of winds and waves, that should not really concern us much.

No, this is one of those August systems that is going to bring some beneficial rain to somewhere. The real question is whether that somewhere is Southern Texas and Northern Mexico, the Central Texas coast, or the Upper Texas coast and Louisiana. Now you may be thinking Eric, what do I have to do to make you bring that wave to the Houston area? First of all, I can’t be bribed—except maybe by ice cream. But secondly, the answer lies in the evolution of a potent high pressure system over the Midwestern United States.

The map below shows a rather intense high developing over Iowa, Missouri, Nebraska and Kansas next week. If the high is too strong, it will force the Gulf system south of Houston and Louisiana. If the high is further south than that, then again, it will force the wave south of the Greater Houston area. So we need that high to be a bit weaker, and a bit further north, to really enjoy the benefits of some widespread rainfall on Monday, Tuesday, and Wednesday of next week.

Things could really go either way at this point. From an emotional standpoint, I’m pessimistic that we’re going to get the rain relief we desperately need. It’s been a long, hot, brutal summer, so why should things change now? From a data-based standpoint, there’s a reasonable chance of rain for our region next week. Hopefully the forecast clarifies itself in the next day or two.

There’s a lot going on with today’s forecast, so let’s get into it. We’re going to focus on four different features: Ongoing, record-setting heat across the area; a weak front moving into Houston today and its effects; the return of extreme heat and humidity this weekend; and finally a bit of a reprieve and increased rain chances next week due to a tropical wave.

Heat streak

After recording a high temperature of 103 degrees on Monday, Houston’s Hobby Airport extended its string of 100-degree days to 11 in a row. The previous record for the airport location, which has kept records for nearly a century dating back to 1930, was nine consecutive days, set back in 1962. Due to its proximity to the coast, Hobby Airport tends to have fewer 100-degree days than the city’s other major climate location, Houston’s Intercontinental Airport. There is a slight chance of breaking the streak on Wednesday, but if not it likely will extend into the weekend.

Weak front

An honest-to-goodness cool front will push into the Houston metro area today. Since it is mid-August, there is not much cooling behind the front, but it will bring some drier air. The front will move in to the region this afternoon, and get hung up around Interstate 10 this evening. During this time there will be stark contrast in dewpoints. If you’re in The Woodlands, for example, the air temperature this evening will be quite warm, but the dewpoints should be low and it will feel rather dry outside. For coastal areas, it will be more of the same—hot and humid. The front should make another push overnight, reaching nearly all the way down to the coast by Wednesday morning. Getting outside around sunrise on Wednesday may be your best chance to enjoy a different feeling in the air before the front retreats north on Wednesday night.

Tuesday

As noted above, the front will bring drier air to the northern half of the metro area today, but air temperatures will still be in low 100s area wide. One concern with the front is that the drier air will lead to fire conditions for the northern parts of the metro area, with relative humidity dropping. This, combined with the dry grass and other fuel on the ground, will burn quickly. A Fire Weather Watch is in effect for this northern tier of counties through 9 pm. With the drier air, overnight lows will drop into the upper 70s for much of the area tonight.

Wednesday

Most of the region will see drier air on Wednesday. Highs will still reach 100 degrees, but at least it will be a drier heat. Rain chances will be near zero, with sunny skies. Humidity levels will start to rapidly recover on Wednesday night, as the front makes its exit.

Thursday and Friday

Unfortunately, we’re going right back into the heat-and-humidity pressure cooker to end the week. Look for highs in the low 100s, with sunny skies and rain chances below 10 percent.

Saturday and Sunday

It looks like another hot and sunny weekend for the region, with highs of 100 degrees to the low 100s. Rain chances may tick up slightly on Sunday.

Next week

The forecast for next week will see our attention diverted to the Gulf of Mexico, where a tropical wave is expected to develop this weekend and progress westward toward Texas. The following plot, from the European model’s ensemble forecast, shows about a one-in-three chance of a tropical depression in the Gulf of Mexico by next Monday or Tuesday. I think that probably overstates the case, but the point is that some tropical moisture will be moving toward Texas early next week. Whether that impacts the southern part of the state, or the upper Texas coast (that’s Houston and Beaumont), remains very much an open question.

What it does mean is that our rain chances will go up next week. The result could be everything from a smattering of showers to a solid 2 to 4 inches of rainfall, we just can’t say for sure. Depending on how widespread showers are, of course, temperatures may also fall some. So have some hope, but also prepare for disappointment. This one could go either way, but it is the best chance we’ve had for relief for a long time.

Good morning. It’s been a long, blistering hot, and largely rain-free summer in Houston, but we’re probably through the worst of it. Several readers have emailed in to ask for a comparison to 2011, and to put this summer’s heat into perspective, and we’re going to do that. But the proper thing is to probably wait until the end of August for an apples-to-apples comparison. A lot of that year’s heat was really baked in during August.

So, on to the forecast. This week is still going to be hot, but there’s a slightly twist. There will be a modest reprieve mid-week with some drier air that you won’t want to miss. And looking ahead to next week, things may really start to change a bit and bring us out of this scorching pattern.

Monday

Well, sorry, but today is not going to yield much change. We are again looking at high temperatures of around 100 degrees, plus or minus, with sweltering humidity. Winds will be slight, generally from the southwest, at 5 to 10 mph. Rain chances are about 10 percent, so not impossible, but if you get a pop-up shower you should definitely go out and play the lottery. Lows tonight drop to around 80 degrees as winds pick up some.

Tuesday

A honest-to-goodness cool front is going to arrive on Tuesday, but you really need to set your expectations accordingly. One, it’s mid-August, so there is no much (any) oomph in terms of cooler air. In fact, highs on Tuesday are going to be just as warm as Monday, in the low 100s with sunny skies. However, there will be drier air, with dewpoints dropping into the mid-50s on Tuesday night. The real question is just how far the dry air gets. I don’t think it will drop all the way to the coast, as the front itself will likely get hung up between the coast and Interstate 10. The forecast map below approximates the extent of the dry air.

In terms of wanting to “feel” a change in the weather, your best bet is probably around sunrise on Wednesday morning. Stepping outside won’t exactly feel refreshing, but at this point it’s going to beat the heck out of what has come so far this summer. Lows on Tuesday night will drop into the upper 70s for the most part.

Wednesday

As noted above, this day should start with drier air for most of the region, and this will linger into the daytime. Expect highs of around 100 degrees, but at least you can act smugly like an Arizonian, and tell your friends, “At least it’s a dry heat.” Which it will be. Sort of.

Thursday and Friday

Alas the dry air will be fleeting, and we’re going to see the return of more humid days with highs in the low 100s.

Saturday and Sunday

The weekend looks hot and sunny as well. At this point rain chances are probably in the 10 to 20 percent range.

Next week

I almost hate to write this, because I don’t want to jinx things. Overall, the pattern shows some relaxation in high pressure next week, and the opening of the door to an atmospheric flow more favorable to rainfall. Right now these rains look most likely in the Monday through Wednesday time period, but because we’re just more than one week out from this, it’s difficult to put much definition on it. So I have some hope right now, but I don’t have details. But goodness knows we need some rainfall so I’ll be keeping tabs on this.