Eric Berger

In brief: In today’s post we dive into the precipitation Houston recorded this summer. Most of the region got significantly less than normal, but we’re not in a drought. Why? We also dig into the forecast which indicates continued warm-to-hot temperatures and an increase in rain chances ahead.

Autumnal equinox looms

Alright, I’ll allow that it does not really feel like summer should be ending soon, especially with a 95-degree temperature reading at Bush Intercontinental Airport on Wednesday afternoon. And in reality, I am sorry to say, I don’t think we are done with heat just yet. Nevertheless, by next Monday we will come to the Autumnal equinox, which by some reckonings marks the beginning of fall in the Northern hemisphere. Note that we already passed into meteorological fall on September 1.

As I noted yesterday, we have had a fairly dry start to September. Since there is not a whole lot else to talk about today, and because the month so far has been dry-ish, I thought we might take a look at how the region did precipitation-wise over the course of the summer. As you can see in the map below, showing “percent of normal” rainfall over the last 90 days, the vast majority of the Houston region has received 50 to 90 percent of normal rainfall during the hottest part of the year.

So why aren’t we in a drought? (Really, we are not). The answer is two-fold. We had some really nice rains in late spring that positioned our soils well for the summer months. And then, while conditions were drier than normal across Houston in July, August, and September, we did have periodic rains that brought a few inches at a time. So if you add that up, we’ve come through summer alright. Things have gotten fairly dry in parts of Houston in the last week, but I’m hopeful that we’ll see some decent rains next week to get us back on track.

Thursday

Yes, you can expect pretty much the same weather today that we’ve experienced for about the last 10 days: highs in the low-90s in central Houston, with slightly hotter temperatures further inland, and slightly cooler closer to the coast. Skies will be mostly sunny, with a slight chance of some showers and thunderstorms popping up this afternoon. Overnight lows will fall into the mid-70s.

Friday and Saturday

More of the same.

Sunday

By Sunday the pattern starts to become a little more unsettled, such that we might see rain chances of 20 to 40 percent by the afternoon. This may help to hold high temperatures down to about 90 degrees in Houston. If you have outdoor plans I don’t think these showers will prove to be too disruptive, as they should be scattered and brief.

Next week

Our pattern really should shift some next week, with better daily rain chances beginning by Monday. Overall accumulations next week will probably be on the order of 1 inch, but also there will likely be a great deal of variability in that. Modestly more clouds should keep highs on the order of 90 degrees, although rainier days may top out in the upper 80s. A weak front may back door its way into the region later next week, but that is far from certain.

In brief: Houston will see plenty of sunshine through the weekend, but we will also start to see some slightly better rain chances. By later Sunday or more likely Monday, the pattern will change more noticeably, with increased clouds and the potential for widespread showers.

A slowly changing pattern

With one or two exceptions, most of the first half of September has seen sunny days with near zero rain chances. This pattern, especially over the last 10 days or so, has seen high pressure dominate our region’s weather. This is now slowly beginning to change, and by this weekend an upper-level system will shake things up. As a result we will see modest rain chances over the next couple of days before the potential for more widespread showers by Monday, which perhaps will persist for much of next week.

Wednesday

Today will bring sunny skies into the region with our typical temperatures in the low 90s for much of the central metro area, with inland areas getting a little warmer than this and the coast remaining a little cooler. There is some support in high resolution models for the development of scattered showers, and perhaps a few isolated thunderstorms, between about 3 pm and 7 pm this afternoon and early evening, before the loss of daytime heating. Lows tonight will drop into the mid-70s for most locations.

Thursday and Friday

Both of these days should see sunny skies. I do think high temperatures may be 1 or 2 degrees cooler, but it will still be hot during the afternoon. Rain chances both days look a bit lower, perhaps on the order of 10 to 20 percent.

Saturday and Sunday

Most of the region should see highs of around 90 degrees this weekend, with mostly sunny skies. However, there will be a slight chance of some showers and thunderstorms as the atmosphere starts to become more unsettled. I think the more widespread rain chances will probably hold off until Monday, but I’m not sure of that. For now I’ll go with about a 20 percent chance of rain on Saturday, and maybe 40 percent on Sunday, but these are kind of fuzzy at this point.

Next week

By Monday-ish we should see an atmosphere more broadly supportive of showers and potentially some thunderstorms. This should set the tone for next week, with something like a 40 to 60 percent chance of rain each day. This should also limit high temperatures to about 90 degrees, or less, on a daily basis. As of yet there’s no strong signal for the next cold front, but maybe something weaker may back door its way in later next week. We’ll have to wait and see.

In brief: Today’s post discusses the state of the Atlantic tropics, which are waking up after an uncharacteristic snooze to start September. We also talk about the persistent pattern of late summer weather here in Houston.

State of the tropics

After the Atlantic tropics have slumbered for nearly three weeks (Tropical Storm Fernand gave up the ghost on August 28), we are close to seeing the formation of a new named storm in the open Atlantic. This would be Gabrielle, and it likely will become a hurricane over the next few days. This storm could well threaten Bermuda early next week, but it otherwise is unlikely to approach any landmasses.

Beyond this storm there is another system behind it, a tropical wave that is just now moving off the coast of Africa and into the eastern Atlantic Ocean. The global forecast models are divided about whether this system will develop, and for now the National Hurricane Center gives it about a 20 percent chance over the next week. This is something to watch to be sure as we are in the middle of September, but nothing to be really concerned about at this point.

The window for hurricanes to strike Texas is closing, but it is not closed yet. I want to wait another week or 10 days before making that call. The only thing I’m really concerned about now, and to be clear this is a very mild concern, is the potential for something to develop in the western Caribbean Sea or southern Gulf, and for such a system to move north toward the state. But again, this is a low probability event.

Tuesday

If you’re looking for new and exciting changes with Houston’s forecast, I’m sorry to disappoint you. Houston remains locked in the same late summer pattern of warm days, mild nights, and mostly sunny skies. It does look as though we will start to see some better rain chances by early next week, but for the most part the likelihood of seeing rain for the next few days will be on the order of 10 or 20 percent. Highs today will be in the low 90s in Houston, with far inland areas perhaps seeing mid-90s, and the coast topping out around 90. With dewpoints in the 60s the humidity will be up there, but it won’t be “summer sticky.” Winds will be light, generally from the east. Lows tonight will drop into the mid-70s.

Wednesday, Thursday, and Friday

And so it will go for the rest of the work week. Highs might be a degree or two cooler as we approach Friday, but most of the region should still reach the lower 90s, with mostly sunny skies. Nights remain in the mid-70s. Rain chances are low, but non-zero.

Saturday and Sunday

High temperatures this weekend will be about 90 degrees, so a smidgeon cooler, but I think that will be accompanied by a slight rise in humidity. There are some chances for isolated to scattered showers, perhaps on the order of 20 to 30 percent for both days, with the better chances toward the coast. But these should be fairly short lived, if they develop. Skies should still be mostly sunny, most of the time.

Next week

Our pattern next week may finally shift a little. Highs are likely to be around 90 degrees, with better rain chances on Monday (maybe as high as 50 percent?) We could see partly sunny skies for much of next week, with scattered daily showers. I’m still not seeing a strong signal for the next cold front, so late summer will probably be sticking around for awhile.

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.