Do we have a chance for some meaningful rainfall this weekend? Probably not

Good morning. For the foreseeable future, Houston’s forecast remains one of very hot weather. The only real watch item of note is rain chances this weekend, particularly on Sunday and into Monday. Unfortunately, the models have trended a bit drier so my expectations of a good, solid soaking are not high. Especially if you live west of Interstate 45.

Wednesday

With high pressure solidly in place, we can expect another day of widespread temperatures of about 100 degrees in the Houston region, with sunny skies and high humidity. This will push the heat index high enough that the National Weather Service has called for a “heat advisory” to cover the area. Winds will not provide much relief, being only light, out of the south at 5 to 10 mph. Nights will continue to be warm and muggy, dropping to only about 80 degrees.

Wednesday will be very hot in Houston once again. (Weather Bell)

Thursday and Friday

More of the same.

Saturday and Sunday

As high pressure eases to the west, it will open the window to a bit more troughiness, which is to say a disturbance pushing down into the southern United States this weekend may have some influence on our weather. However, the strength of any disturbances or boundaries pushing into the Houston metro area is suspect, and the influence of these is likely to be felt most keenly on the eastern half of our our region.

European model odds for rain accumulations of 0.1 inch or greater through Monday. You can see the sharp gradient between east and west Houston. (Weather Bell)

All of that is to say that we can expect partly to mostly sunny skies this weekend, with highs generally in the upper 90s. There will be a chance of showers and thunderstorms each day, perhaps peaking at 30 to 40 percent on Sunday. Unfortunately, accumulations look slight. Most of the modeling I’ve looked at suggests there is about a 50 percent chance that most of the area sees on the order of one or two tenths of an inch. So really, only a light and fairly inconsequential dusting of rain. There’s always the chance that things will change as we get closer to the weekend, but right now we’re trending away from meaningful relief from the heat and emerging drought.

Next week

Monday and perhaps Tuesday should be another day of temperatures in the upper 90s with modest rain chances. After that, I’m afraid, high pressure will probably begin to assert its control once again.

June and July of 2022 set records for heat in Houston. This summer feels even hotter, though.

By raw temperature values, June and July 2022 were each the hottest June and July that Houston experienced in about a century and a half of records. The average temperature last June was 86.7 degrees, and July was 88.0 degrees, both of which beat the previous monthly records by 0.5 degrees Fahrenheit. So far, the average temperature in June and July has been slightly lower than the torrid pace of 2022. However, to me, this summer feels hotter, and a look at the underlying data reveals why this is so. We can see this in both the heat index—which factors in both temperature and dewpoint—as well as nighttime temperatures.

Hours with a heat index above 105 degrees from June through mid-July. (Space City Weather)

Another way in which this summer’s heat has been extreme has come in terms of nighttime temperatures, making it feel like it is never cool outside. Here’s a look at the number of nights this summer of 80-degrees or warmer.

Comparison of 80-degree nights. (Space City Weather)

So what is going on here? The primary driver appears to be an anomalously warm Gulf of Mexico. We can see the warm water’s influence in the sharp jump in heat index (again, higher humidity) and very warm nights at Hobby Airport. This sizzling Gulf of Mexico may portend bad things for hurricanes when the tropics season really gets going in a few weeks, or wind shear may come to our aid. We cannot be sure. But the Gulf’s heat is pushing our temperatures and humidity higher this summer. There is also an underlying impact from the urban heat island effect, but there has not been much urbanization around Hobby Airport between this year and last.

The bottom line is that the planet is warming, and the heat records we’ve seen falling in recent years are a consequence of that. It is probably not correct to say this is “extreme” heat any more. This is simply hot summer weather during an El Niño event. Some of our readers do not like us referencing climate change on this site, and that’s fine. We do not do it often, but sometimes plain talk is warranted. We are an objective, reality based site, and report what we are observing. One reader wrote me yesterday, saying we should stay in our lane. Well, ma’am, weather is our lane. And yes, there is a significant gulf between weather observations and the general climate. But climate is the background influence on local weather conditions. And the planet’s overall thermostat is rising. We can either pretend this isn’t happening, or we can have an adult conversation about what we should do about it. Put simply, the recent summer heat in Texas, and Houston, is abnormal; and in the history of meteorological observations here, it is unprecedented. Also, it sucks.

Now, on to the forecast. Which is hot, humid, and generally pretty awful until the weekend.

Tuesday

High temperatures today will reach 100 degrees for much of the area, with sunny skies and fairly high humidity. Winds will be fairly light, out of the southwest at around 5 mph. Low temperatures tonight will only drop to around 80 degrees, although winds may be a bit more gusty from the south. Rain chances are, with the sinking air, very nearly zero.

Wednesday through Friday

As high pressure holds sway, this hot and sunny pattern will more or less persist. Of this, there is not much more to say.

As the high retreats west this weekend, it will open up our region to a bit of storminess. (Weather Bell)

Saturday and Sunday

By this weekend the omnipresent high pressure system will start to recede to the west, and this should allow a series of atmospheric disturbances to push southward into the Houston area. It remains too early to be able to offer a definitive forecast for what this will mean. But probably, Saturday will be mostly sunny, with highs in the upper 90s, and perhaps a 30 percent chance of rain. Sunday should see a few more clouds, with highs in the mid-90s, and an even healthier chance of rain. By no means are we expecting a washout, but you might hope for 0.25 to 0.5 inches of rain through Monday.

Next week

Some rain chances persist into Monday, but after that conditions locally look drier. Highs, probably, will climb back into the upper 90s next week as we continue rolling toward the peak of summer in early August.

Very high heat continues through this week, but then maybe some slight changes are on the way

Good morning. Very warm weather will continue this week, with high temperatures of about 100 degrees on a daily basis. However, it appears that the ridge of high pressure anchored over the southwestern United States will retreat somewhat by this weekend, allowing for some partly cloudy skies and, potentially, even some rain chances to seep into the area. Do not look for too much relief, but some chance of rain is at least better than none.

When does peak summer occur? (@climatologist49 on Twitter)

I also want to provide some big picture perspective on summer. It is now July 17. Some parts of the United States, including Alaska and the upper Midwest, have reached the peak of summer. However, for Houston the peak of summer does not come until early August—August 4 for Bush Intercontinental Airport, and August 7 for Hobby Airport. Truth be told, the period from mid-July through early September is typically the hottest of the year for us. Let us hope that things turn around this year.

Monday

If you ventured outside over the weekend, you have a pretty good idea for what to expect this week. High temperatures today will push 100 degrees for much of the area away from the immediate coast, with overnight lows only dropping to 80 degrees. Skies will be sunny, with light southwest winds of 5 to 10 mph. Rain chances are virtually zero.

Tuesday through Friday

Conditions will be virtually the same for the rest of the work week, with the only change that highs may be a degree or two below 100 degrees. Still very hot, very humid, and very sunny.

Saturday and Sunday

As high pressure backs off this weekend, we should see the development of a few clouds and, accordingly, some slightly lower afternoon temperatures. Look for highs in the mid- to upper-90s. We also may see the rotation of atmosphere disturbances into the area, and these could be the trigger for some rain showers.

The details of such systems this far out are impossible to predict, but I’d broadly predict a 20 to 30 percent chance of rain on Saturday, and perhaps a 40 to 50 percent chance of rain on Sunday. Whether these showers come to pass will also have an effect on air temperatures of course. All of this is fairly hazy at this point, but it is at least possible that the pattern will somewhat change.

Next week looks hot, but not extremely so. (Pivotal Weather)

Next week

Looking ahead to next week, it appears as though our weather will be fairly typical for late July, which is to say high temperatures in the mid- to upper-90s. We are, after all, approaching the peak of summer.

A closer look at this summer’s heat in Texas, especially at night

The forecast is unmoved by the pleas of those of us looking for change. Simply, there is no realistic opportunity for relief showing up in modeling over at least the next week and perhaps 10 to 12 days.

The forecast from the National Blend of Models may be running a degree or two too hot at times by day, but the more important thing here is that there is no meaningful break in heat showing right now. (Weather Bell)

Here are rain chances over the next 7 to 8 days based on our interpretation of the European and GFS modeling:

The only day right now that appears to have a potentially mentionable chance of rain is Sunday, mostly east of I-45 and north of I-10. And even that’s not exactly a great chance.

There is one wrinkle in the forecast, and that comes on Sunday. A disturbance tracking into the Great Lakes may help erode the northeastern periphery of the ridge of high pressure juuuuust enough to perhaps allow for a weak disturbance to set off a few showers or storms from the northwest.

What meager rain chances we do have through next week are almost entirely confined to Sunday, isolated, and east or northeast of Houston. (NOAA)

This seems most likely to occur in Louisiana, but I would say if you live in Liberty County or closer to the Beaumont area, your chances look marginally better than zero for a cooling downpour on Sunday.

But other than that, there’s no reason to make this forecast more difficult than it needs to be. Roughly 100 during the day, roughly 80 at night, copy, paste from now through late next week. Heat Advisories are likely most days with at least a slight chance of us getting put back under an Excessive Heat Warning again at some point. Is there a chance something unforeseen presents itself before next weekend to help cool us a bit? I guess so, but I don’t see where that comes from right now. So expect another week of the same.

It’s the nights that hurt

Throughout this long hot summer, currently the 6th hottest on record, we have set a total of zero record high temperatures at Bush Airport. But we’ve managed to set (or tie) 10 record warm minimum temperatures as of yesterday. How have other parts of Texas fared?

With the exception of San Angelo and Corpus Christi, every major south, central, or west Texas city has set or tied more warm nighttime records than daytime highs. (Data from NOAA)

Most places have seen more nighttime low warm temperature records than daytime record highs in Texas. I omitted cities in the Panhandle and East Texas, as they’ve generally seen a bit less heat versus the south, central, and western parts of the state. Del Rio has had a hellacious summer, with 40 percent of their nighttime warm low records since June 1st set or tied this summer alone. Dallas and Houston stand out as the only two cities with no record highs (officially). Dallas largely escaped the worst of the June heat. If we take a look at this chart in a month, I expect that we would see a continuation of this trend of nighttimes being worse relative to normal than days.

Let’s look at this another way. The magic number in Texas for a really gross overnight is about 80° or so. Here is a look at how many 80° nights have occurred in 2023 so far (plus what’s forecast through next Thursday), compared to the annual record for nighttime lows of 80 or warmer.

Both Midland and El Paso should exceed their previous annual record for nighttime lows of 80 or warmer by next week. Del Rio, Austin, San Antonio, and Houston are getting closer. Other cities have a longer way to go but almost all are in the top 5 or 10 years on record already. (Data from NOAA)

In San Angelo, Abilene, and Dallas 2011 remains the benchmark summer for nighttime lows of 80 or warmer. Given the relatively cooler June, Dallas has a very long way to go. With more heat, San Angelo or even Abilene could come closer, however. Houston’s record of 26 overnights of 80 or warmer was originally set in 1962, but we should be only 5 days away from matching that by this time next week. For El Paso and Midland, their previous records look to be toast. El Paso’s was set in 2020 and Midland’s occurred previously in 2011. Austin and San Antonio should not be terribly far away from breaking their records for most 80 degree nights. Austin’s record was set in 2019 and again in 2020, while San Antonio’s stands from 2010.

Why does this all matter? Because heat becomes an exacerbated health and infrastructure issue when we do not cool off at night. Air conditioning units have to work harder. If poor climate controlled homes don’t cool down properly, then people (especially the elderly) become more vulnerable to heat illness. You’re simply being exposed to hotter temperatures for longer stretches of time. This is why we emphasize checking on the vulnerable. Don’t forget pets too.

The reason for so many record warm lows outpacing record highs varies from place to place. Some of it is attributable to the urban heat island effect and population growth and sprawl. Locally, the warm Gulf is likely a contributor as well, helping to increase humidity and raise the “floor” that temperatures can feasibly drop to overnight. But it does not explain these extremes entirely. Warming nights (and the warming Gulf) firmly fit the science behind climate change. Yes, that’s part of the reason too. When you put it all together it is making for a pretty rough summer, even by our hearty Texas standards.