Eric Berger

In brief: Houston’s sunny and warm, but not super hot weather will continue this week. As we get closer to the weekend we may see some slightly better rain chances, but I would not expect any serious accumulations. In this post I explain why this is pretty normal for September.

Taking stock of September

We are now nearly two weeks into the month of September. The heat over the weekend may have felt a little bit too much like summer, but the reality is that for Houston September often feels like an extension of August. This is the genesis of the ongoing debate Matt and I have over which month has the worst weather here. For the record, the correct answer is August. Always August.

When we look at temperatures to date for this September, we are actually running slightly below normal so far this month. How is this possible? Well, recall we had that nice, early season front a little more than a week ago, and that knocked our nights into the 60s and lowered the humidity. That has made our weather over the last couple of days—which actually is pretty typical for mid-September—feel warmer than perhaps we think it should be. The front fooled us.

The bottom line is that although the forecast for the week ahead ahead appears to be pretty warm, and pretty humid, it is not abnormally so for this time of year. In fact it’s fairly typical. Fall is on the horizon, but alas it is not here quite yet.

Monday, Tuesday, and Wednesday

If you liked the weather this weekend, you’re in luck, because that pattern will continue. We will see partly to mostly sunny days with high temperatures around 90 degrees closer to the coast, mostly low-90s for central parts of the Houston region, and mid-90s for inland areas such as Katy and The Woodlands. We will see a chance of some pop-up showers each afternoon, but the overall odds are only 10 to 20 percent. With afternoon dewpoints in the 60s it will feel humid, but not oppressively so during the peak of summer here. Nighttime lows will generally fall to the low- to mid-70s.

Thursday through the weekend

The pattern does not change a whole lot through the weekend, although we will see a slightly more disturbed upper atmosphere. What does that mean? Would see some slightly better rain chances by Thursday or so. They’re not great, but at this point it is possible that we see some 20 or 30 percent daily chances through the weekend. Any accumulations appear to be modest, so don’t expect heavy or prolonged rainfall. Highs remain in the vicinity of the lower 90s.

Does this pattern ever end?

There is some evidence to support a greater likelihood of rain by early next week, which might cool us down into the upper 80s. But this mostly sunny, mostly hot weather pattern in September is persistent, and I want to see more definitive evidence before suggesting it’s going to end.

Tropics

We are nearing the end game of the tropics and Texas for this year. However, we have not gotten there yet. Looking across the Atlantic basin, we are seeing things start to heat back up after a calm beginning of September. To be clear, we are presently tracking no threats to the Gulf or Texas. But we probably will have a hurricane in the open Atlantic over the next several days. We’ll take a deeper look at the tropics in tomorrow’s post.

In brief: Today’s forecast is our GIF to you, our beloved Houston readers. Houston’s weather will be unchanging for awhile, and it’s been five years since we’ve done a GIF-only forecast. So it’s high time we do it again.

Basically our forecast for the next 10 days:

You’ll walk outside every morning, look up, and see this.

Afternoon temperatures will basically feel like…

The humidity will be such that, if you stay outside too long your co-workers will be like …

Rain? There will be …

What will be different this weekend?

Surely a front or something is coming next week to bring some rain, or pull us out of the 90s, right?

So when does this change?

Matt will have a more in-depth forecast for you tomorrow. Probably. Maybe. I guess we’ll see.

In brief: After a pair of almost fall-like weather days, Houston’s pattern will tilt back toward summer. As high pressure asserts control our forecast looks to be locked in for pretty much the next 10 days: hot days, lots of sunshine, and virtually no chance of rain.

High pressure in September

When it comes to weather, most people understand that low pressure equates to the potential for stormy conditions, whereas high pressure creates a more stable atmosphere with sinking air. At most times of year when we see high pressure (sinking air) this leads to mostly sunny or cloudless days. This can feel fantastic in February or March, but decidedly sultry and hot in July and August.

By the middle of September we are starting to edge toward fall, with shorter days and a lower Sun angle, high pressure hits a little bit different. Instead of high temperatures of 100 degrees like in August, we are likely to see highs generally in the mid-90s. Instead of lows around 80 degrees, we are likely to see low- to mid-70s. Dewpoints should be 5 to 10 degrees lower which means the air will feel slightly less humid than peak summer.

So for those who want a little bit more summer, you’re in luck. For those pining for fall after the last couple of days, it’s going to be a loooong week, at least.

Wednesday

It is another pleasantly cool morning across the region, with the usual spots such as Conroe dipping into the upper 50s and much of Houston in the mid-60s this morning. Alas, all good things must end. Winds will turn easterly today, increasing an onshore flow, and starting to increase humidity levels. For the most part I think highs today will remain in the low- to mid-90s, with sunny skies. Lows tonight will only drop into the mid-70s, so about 10 degrees warmer for most locations. With light winds today, conditions are favorable for producing elevated levels of ozone. An Ozone Action Day is in effect.

Thursday through Sunday

Each of these days is going to be very, very similar. We can expect mostly sunny to cloudless days with highs in the low 90s near the coast and mid-90s for most of the rest of the area. Some far inland locations may push into the upper 90s. Most days will have modest southeasterly winds at about 10 mph. Nights will be in the mid-70s. Rain chances will be essentially zero. If you have outdoor plans our confidence in this forecast is very high.

Next week

Not much changes for at least the first half of next week: same skies, same temperatures, similar humidity. Rain chances are low through at least Wednesday or Thursday, by which time coastal areas may start to see some isolated showers. Really, I don’t see any real spark of change in this pattern until at least next weekend, and maybe not then.

Atlantic tropics

Today is the historical peak of the Atlantic hurricane season. Yet this year, there is precisely nothing to talk about. That is ideal!

In brief: It’s officially Fall Day in Houston, with the season’s first 65-degree temperature reading this morning. We are also excited to announce that we’ll be holding our Fall Day Celebration on October 25 in Houston. More details in today’s post, which discusses our largely unchanging weather for the next 10 days. We also talk tropics.

Fall Day celebration

The temperature at Houston’s official weather station, Bush Intercontinental Airport, fell to 65 degrees this morning (and it currently has reached 64, as of 6:20 am). That means we can officially declare today as “Fall Day” in Houston. If you’re unfamiliar with this little tradition, it’s simply the day when we get our first real taste of fall in the city after a long summer.

Speaking of this, I’m excited to announce that we are planning a special Fall Day Celebration for Saturday, October 25. This year’s event will also commemorate the 10th anniversary of Space City Weather. This year we are gathering at Midtown Park from 10 am to Noon. We will have more information soon, but rest assured we are planning a special event for you and your families. Come celebrate with us!

Tuesday

This deligtfully dry air will persist today and tonight before a more easterly flow starts to raise humidity. As a result we can expect sunny skies today, with high temperatures around 90 degrees. With dewpoints in the 50s, this afternoon will like Monday bring a somewhat dry heat into the area. This evening will be pleasant. Lows tonight will drop to around 70 degrees in Houston, with cooler conditions further inland.

Wednesday through the weekend

As high pressure builds from the west, I don’t expect much variability in our weather for the remainder of the week. Each day should bring sunny skies and high temperatures in the low 90s in Houston, with areas further inland (i.e. Katy and The Woodlands) likely pushing into the mid-90s. Dewpoints will be in the 60s, generally, so while the air will be more humid, it won’t be the super sticky humidity we see during summertime in Houston.

Lows will generally fall into the low- to mid-70s. Rain chances throughout this period will basically be zero, except for the immediate coast, which might see slightly higher chances (i.e. 10 or 20 percent) on some afternoons.

Next week

This pattern has to change at some point, right? Well, eventually. Mostly, however, I expect it to persist into at least the middle of next week. At that point rain chances may tick up slightly, but I don’t see any evidence of the next front at this time. So after today it will be late summertime weather for awhile.

Atlantic tropics

It’s very quiet there for what is typically the peak of the Atlantic hurricane season. We have zero concerns at this point. When we look out for the next 10 days, conditions look to be fairly quiet. The sub-seasonal forecast from the European model, shown above, predicts significantly less activity than normal in the Atlantic basin (40 percent of normal). By the last 10 days of the month this model is back to predicting near-normal activity in the Atlantic, and overall conditions should improve. But long-time readers of Space City Weather will know that our window for seeing a hurricane landfall in the greater Houston region is closing. I’m certainly not ready to declare the season “over” for Texas, but we are just weeks away from that happening. So we’re in the home stretch.