Matt Lanza

In brief: After a week straight of 100s, we’re now on the downtrend, albeit slowly. Look for increasing rain chances heading toward next week and less hot (but not quite cool) weather. Each day will provide us at least a non-zero chance for a cooling downpour or thunderstorm.

Yesterday was Houston’s seventh consecutive 100 degree day. And while we may make light of this summer’s heat after last summer, did you know that this was only the 14th time since the 1890s that Houston has strung together a week straight of 100 degree weather? It’s true. Of the 14 instances of a week of 100s, eight have occurred since the year 2000. Only one occurred prior to 1962. The average temperature over the last week has been 90.2°, which only ranks tied for 94th hottest seven-day stretch all-time. So there you go. The good news is that the worst is over, and we can introduce the word “rain” again a little more frequently.

Today

We have some storms this morning drifting south and west out of Fort Bend County and into Matagorda County. So be on the lookout for that. Otherwise, we may get through today without a heat advisory.

We’ve got a slightly cooler air mass, slightly more humidity, and slightly higher rain chances today than we had yesterday. Some people did see rain and hear thunder on Thursday, including Sugar Land and Missouri City, as well as southeastern Brazoria County. Today, a few more of us should see raindrops besides those seeing them this morning. Expect scattered activity to pop up later, but rain chances are only around 20 percent. Where it rains later, look for temps in the 90s falling into the 70s or 80s for a time, then heating back up after it stops. Where it doesn’t rain, look for mid to upper-90s.

Weekend

The forecast for this weekend is straightforward but also tricky. In general, it will be sun, clouds, 90s, and a chance of a shower or storm with the sea breeze each afternoon. However, based on the model guidance I’m seeing this morning, I would lean toward Saturday being a quieter day overall and Sunday being more active, with a greater coverage of showers and storms. The European model and its AI model seem to support this idea, but I would have the umbrella and a plan to scoot inside on either weekend day.

Next week

We get to watch two things next week. The first will be this disturbance in the Gulf that pivots onshore on Sunday night and Monday. It will not develop into a tropical system, but it will continue rain chances into Monday, Tuesday, and Wednesday for us. The second item may be a piece of another tropical wave over Hispaniola today that moves into the Gulf next week and adds another little bump in moisture levels toward next weekend. No development is expected. That said, it may peel off to our east into Louisiana before arriving.

We are looking at some modest rainfall overall, especially south of I-10. Locally heavier rain is likely in a few spots that are TBD right now. Basically, there will be a chance of rain every day next week, with some day to day variation in coverage and specific locations of highest rain chances. This should not be a major rain setup for Houston, but it will certainly be a change from this week. Highs will be in the low or mid-90s, so not exactly cool but with periodic rains and more clouds, it will be more tolerable overall.

The tropics remain quiet. More on that at The Eyewall later this morning.

In brief: Heat and humidity will be a bit worse than usual for August this weekend, and although things ease up just a bit next week, we will remain hot and mostly dry. There may be a shift toward better rain chances next weekend.

Today through next week

Sunny, hot, humid. Highs in the mid-90s to near 100 degrees. Maybe a rain chance. And you know what? I congratulate my neighbors that have seen showers this week and may luckily see showers into the weekend too. Good for you, I say!

Why is this happening?

In all seriousness, we all know the forecast at this point, so I figured I’d take a moment to discuss the “why” today. It’s kind of fascinating. Last summer we saw a suppressed, strong ridge of high pressure over Mexico that would continuously flex over Texas. This kept us in the 100s daily and made last summer another level of terrible. This summer? Much different. Texas has been stuck generally between persistent areas of high pressure, one in the East, one in the West. To date, it’s been the hottest summer on record by a mile for Las Vegas and Phoenix. For Atlanta it’s the fourth hottest to date, and for Raleigh, NC it’s the third hottest. For Houston, it’s “only” been the 12th hottest summer and, even less impressive the 24th hottest for our frienemies in Dallas.

But so far this month, the pattern has changed allowing for the Western ridge to expand into Texas somewhat, which has in turn allowed us to crank the heat. Over the next five days, check out where the ridge of high pressure situates.

Over the next week it basically sets up shop just to our west, which will keep us firmly under the influence of heat. Unlike last summer, we aren’t directly underneath the high, so we will have some modest rain chances and it won’t be as extreme as was seen last year. But our weather will continue to be controlled by this feature. Odds of above normal temperatures and below normal precipitation will remain strong heading deep into next week. The next few days should be the worst of it for now. We may see a relaxation in this pattern later next week with the ridge retreating a little more to the west leading to slightly better rain chances toward next weekend.

Whatever the case, this coupled with a quiet tropical Atlantic over the next several days (outside of Ernesto) is not necessarily a bad thing for Houston. We’ll take it, but do take it easy with this weekend’s heat.

In brief: August will continue to August in Houston, with hot weather, hazy skies, high humidity, and at least some low-end shower chances. We will continue to see the heat persist into next week, but that will also hopefully shield us from any tropical troubles.

Today

More of the same continues today, but this time we may add a slightly better chance of a few showers or thunderstorms this afternoon. The setup is a bit complicated, but we have a couple boundaries headed our way, and this coupled with daytime heating and the inland moving sea breeze off the Gulf could help at least fire up a few thunderstorms around the area. Otherwise, it’ll be another scorcher with highs near 100, heat advisories, and air quality alerts for high ozone.

Weekend

More of the same. There will continue to at least be subtle rain chances this weekend, but consider yourself lucky if you get a downpour. Highs will be in the upper-90s, with more borderline heat advisory criteria. I guess that’s a little cooler? I don’t know. Cooler or not, it’s still going to be hot.

Next week

We’ll keep this simple today: There may be some subtle nuance day to day in terms of exact temperature or exact shower chances, but the majority of next week looks stable and hot. High pressure is in control (more below), and that means sun, highs near 100, and heat index values pushing heat advisory criteria daily.

While we cannot entirely rule rain out of the forecast next week, daily chances really look meager right now. This is as reminiscent of last summer as we’ve seen so far this year.

The reason for all this is that high pressure in the upper atmosphere, something that’s been relatively absent this summer over Texas is finally locking into place. We usually see this at times during summer leading to more concentrated “heat wave” type periods. Well, it’s coinciding with August and our worst heat this year it seems. As long as this stays in place, which it looks to do for the most part over the next 10-12 days at least, we will continue with a pretty stable forecast. If you look at the map below, just notice the “594” circle over Texas. That’s a pretty strong sign of good heat and mainly dry weather in Texas in August.

The upshot of all this is that it would likely keep us protected from any tropical nonsense, so long as it stays in place. We’ll see if that’s the case. Check The Eyewall later this morning for the latest on the next Atlantic wave, which we currently believe will stay east of the Gulf.

In brief: Rain has been manageable so far today. We expect more rain this evening, with scattered heavy downpours. Another round of potentially heavier rain is possible on Thursday morning. We’ll maintain our flood alerts as is for now.

Rain has been mostly under control since this morning thankfully. The next wave is coming ashore now at the coast, and even this one is checking in a bit more manageable than it looked this morning.

Still, rain rates around 1 inch an hour or so are likely as this pushes ashore. As it moves north and east, we’ll see most rain impacts on the southeast side of Houston, with isolated to scattered downpours north and west. Total rainfall will be an additional inch or two at the coast and less inland (except in isolated heavier downpours) through this evening. Any street flooding is expected to be more nuisance in nature.

Looking ahead, modeling is suggesting another rather beefy area of rain and storms approaches the area overnight or early on Thursday morning. This would be capable of perhaps another 1 to 4 inches of rain.

There remains enough uncertainty in the models that we use for these type of rain events that I think maintaining the Stage 2 alert for the coastal areas and Stage 1 inland is the right move. One model we track closely during these events suggests as much as 7 to 10 inches could fall in a worst case scenario between Galveston and Port Arthur and southwest Louisiana. I would especially watch the Beaumont-Port Arthur area in this setup. We don’t expect that outcome, but we can’t rule it out entirely. For the majority of metro Houston and suburbs, another inch or two, with some seeing more and some less seems reasonable.

Eric will update us on Thursday morning with the latest regarding the rainfall.