Matt Lanza

Momentum is building for the heat to relax (a little) in Texas, but it’s still at least 10 days out

I want to start my Friday post on a positive note. For weeks it feels like, Eric or myself have been writing these posts saying “we honestly don’t know when this excessive heat is going to meaningfully end.” We all know it will still be hot; it’s August after all, but it would be nice to tone it down just a little and maybe bring some rain back into the picture.

Temperatures over the next 5 days are certainly going to be a good deal above average, even for August across all of Texas. (Weather Bell)

Eric has alluded to some potential change at the end of posts the last day or two, and I think we’re starting to build some legitimate momentum for this to occur. As we move beyond days 7 to 10, we begin to see a bit of a shift in the pattern showing up in modeling. High pressure in the Southwest & Texas shifts just a little more to the west. Heat is established now in the northwestern corner of the country and parts of Canada.

Some changes evolve late and beyond day 10, which include big heat in the Pacific Northwest and western Canada, a cooler trough digging into the eastern half of the country, and high pressure just drifting a little to the west from Texas into Arizona and New Mexico. (Pivotal Weather)

What this may do is help carve out a trough in the eastern half of the U.S. This is helpful for us in Texas because if this happens, it sort of puts us in the middle. Meaning, yes, it will still be fairly hot here, but not at record levels (think upper-90s instead of low-100s). It would also probably allow for the door to the Gulf to swing back open again and bring back at least some rain chances.

This is good news because drought continues to gradually worsen in Texas. The Climate Prediction Center hazards map for August 11-17 shows that many areas in Texas are at risk for “rapid onset drought.”

The Climate Prediction Center has noted continued excessive heat risk for Texas on August 11-13, but they also have highlighted much of East & South Texas for being at risk for “rapid onset drought.” (NOAA CPC)

What exactly are they talking about? Essentially “flash drought,” which is what happened in the Central Plains in 2012. Drought quickly goes from kind of bad to very bad very fast. This can have implications on agriculture, water supply, lake levels, etc. We really don’t want to be dealing with a flash drought here, but given the recent issues with wildfire flare-ups, as Eric noted yesterday, we may already be descending that path.

This is why we are really, really hoping that what we see beyond day 10 can hold. Fingers crossed.

Today and the weekend

Meanwhile, yes, it’s more of the same. More heat. More advisories or excessive heat warnings. More humidity. Drink more water and try to limit outdoor exposure when possible. Please also check on your neighbors. There have been a couple instances of showers popping up in recent days in central part of the Houston area. That could happen again today or tomorrow, but consider yourself extremely lucky if it does.

Summer to date, we’ve just tied 2009 for the 3rd hottest on record in Houston. We are only a couple tenths of a degree behind 2011 for 2nd hottest, and over the next 7 to 10 days, we’re likely to go neck and neck with that summer. I suspect 2011 will pull away in the end, assuming our pattern does change some later in the month.

“Hey Siri, show me what stability looks like in a weather forecast.” (Weather Bell)

Next week

Copy and paste. More heat and more sun. Look for a slight rain chance Tuesday afternoon and then maybe again by Friday. Any changes that take place in the weather pattern would not materialize before next weekend. So buckle in.

Drought quickly expanding in Texas, while more substantial heat is likely next week

We continue to slip back into drought across the Houston area, and all of Texas for that matter. Since last week’s update, the report issued on Thursday showed drought expand to cover over 35 percent of the Houston region, up 5.5 percent since a week ago. Meanwhile, severe drought has arrived for eastern parts of the metro area into Liberty and Chambers Counties.

Drought now covers over a third of the Houston region, with the worst of it being east and south of the city. (US Drought Monitor)

Texas as a whole is seeing severe drought grow, up to almost 20 percent of the state now, up from about 6 percent a month ago. We’ve fortunately had some downpours pepper parts of the area this week, but it’s not even close to what we need to start reversing this process. We’re far off, and the upcoming weather pattern seems to suggest we are not getting any closer to resolution.

Today

More of the same. Look for high temperatures in the upper-90s and a few cooling showers here or there that you can thank your lucky stars, should you receive one.

Weekend

Hot! Rain chances drop from a paltry 15 percent or so on Friday to 10 to 15 percent on Saturday and 5 to 10 percent on Sunday. And even those values may be somewhat generous. Look for heat index values to tick upward into mid-100s again, possibly back to borderline heat advisory levels by Sunday afternoon. High temperatures will be in the upper-90s on Saturday and near 100 degrees Sunday and lows will be in the 70s to near 80 once again.

Next week’s heat

So if you follow the animating map below, you’ll see what’s happening next week. High pressure, or the core of the heat is established over the Southwest today. By Sunday, it will focus over Colorado, and by Tuesday, it’s centered right over Oklahoma and North Texas.

High pressure, the core of the heat, will drift into Texas next week before retreating back to the Southwest next weekend. However, because it is likely to strengthen significantly again, it may not lead to much cooling for Texas when it shifts back to our west. (Tropical Tidbits)

This means that the core of the heat will follow. We’re in for it next week, folks. No way to sugar coat this.

Some of the hottest temperatures of summer settle over us next week. (Weather Bell)

Models have generally been running too hot in terms of temperature this summer, but we’ve more than made up for it with humidity. Regardless, expect a string of heat advisories pretty much every day next week, with highs generally 99 to 102°, high humidity, and morning lows around 80 or so. It may not *feel* quite as bad as what we saw in June and earlier this month, but it won’t be off by much.

The high pressure ridging that focuses the heat may retreat back to the Southwest by next weekend, which should hopefully allow for just basic summer heat instead of the next level stuff we get next week. But I will say that some models are hinting that as the ridge pulls back to the Southwest it will strengthen further (yesterday’s 12z GFS model had the strongest modeled ridge I’ve seen on a model in my entire career). You can see that on the above animation. While extreme heat would stay to our west in that scenario, it may mean that we continue predominantly near 100 and mostly dry into the first full week of August. We shall see, but I see no reason to think any significant change will occur in Houston anytime soon.

So what of rain chances? Not great. We max out today and maybe next Saturday around 15 or so percent. That’s about the best we can muster right now, and even that may be a little generous. We know some folks, especially those that are in farming are hurting and need rain. We wish we had better news.

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.

We are not quite done with rain chances in the Houston area yet as potent summer heat looms

Yesterday saw some locally hefty rains across the area. We picked up anywhere from 1 to 4 inches of rainfall between Pearland and Westchase, with another bullseye out west of Cypress along 290 into Waller County.

Radar estimated rain totals were as high as 4 inches in parts of Waller County and close to that near the intersection of the Westpark and the Beltway. (NSSL)

Areas just south of The Woodlands saw 2 to 3 inches of rain as well. Even Matagorda Bay (not shown above) saw about an inch or more in most the area. We are not yet done with the rain, though we do not believe today will play out quite as yesterday did.

Today

We’re starting the day off with an area of rain sitting near Matagorda Bay and just a few showers in and around Galveston Bay and the island.

Heavy rain is impacting the Matagorda Bay area this morning, with just a few showers and rumbles of thunder around Galveston Bay. (RadarScope)

As the day goes on, look for more scattered thunderstorms to develop across the area. The highest chances will be south and east of about Cypress. So much of the area will see showers or at least hear thunder again. Those that see showers today could see as much as an inch or two of rain, while others will see next to nothing. Look for generally low 90s and light winds (except localized gusts in storms).

It feels like we have one or two more decent chances at rain today and tomorrow before the spigot is basically shut off.

Saturday & Sunday

If you have weekend plans, you will probably be fine. But there will certainly be thunderstorms in the area. Look for about a 30 to 40 percent chance of showers and storms on Saturday, followed up by about a 20 percent chance on Sunday. Outside of showers, look for sun, clouds, and slowly increasing temperatures. We’ll be in the low to mid-90s tomorrow and firm mid-90s on Sunday. Morning lows should be in the 70s on Saturday before back closer to 80 degrees on Sunday morning.

Early next week

Rain chances don’t quite go to zero to start next week, but they will drop off to the 10 to 20 percent range on Monday and Tuesday. As that occurs, look for temperatures to warm into mid to upper-90s, with morning lows near 80 degrees. It will begin to feel rather uncomfortable with peak heat index values over 105 degrees.

We expect to start seeing the question “when will this round of heat ease up?” soon, and unfortunately we don’t have a clear answer right now. (Weather Bell)

Heat returns

By the time we get to Wednesday, look for high temperatures near 100 degrees, give or take a couple, with morning lows around 80 degrees. The difference between this heat wave and June’s heat wave will be noteworthy. In June, the high pressure setup directly over northern Mexico or Texas, and we just baked with extreme (for June) heat. This time around, it looks more like a traditional summer heat wave, with high pressure centered over the Desert Southwest. It will strengthen and expand to a point where we see just a lot of generically “hot for July” weather in southeast Texas but probably not extreme heat. If the June pattern had recycled this time around, we’d probably be talking 102 to 105 degrees every day. Instead, we’re probably talking 98 to 102 degrees, which while quite uncomfortable is not terribly uncommon in July.

That said, I fully expect heat advisories to re-enter the chat by early next week. As this will again be a potent, long-duration period of high heat and humidity, heat precautions should be taken as they were in June.