Matt Lanza

In brief: Hit or miss showers will continue across Houston into the weekend, with coverage slowly increasing each day. A more concentrated heavy rain/storm chance is in the cards Monday and Tuesday with some flash flooding possible. Temperatures heat up later next week and weekend.

Some parts of Houston are in the “rain o’clock” phase of summer, where you hit the right time of day, and the storms start to fire. Rain totals this week have been quite variable, with some places seeing nothing and others, like the East End through Galena Park and Cloverleaf seeing 2 to 4 inches of rain. As we head toward next week, more places will participate in rainfall once again.

Today and Saturday

Both today and tomorrow look fairly similar with isolated to perhaps scattered afternoon thunderstorms developing across the area. Once again, many locations will come up empty, but some could easily pick up a quick inch or two. Tomorrow may have slightly higher coverage of storms than today. Either way, outside of that it will be seasonably hot and humid with highs in the low-90s.

Sunday

More of the same is expected here, however coverage of storms on Sunday could be a tinge higher than Saturday. Highs will be near 90 degrees or in the low-90s.

Next week

Here’s where the pattern begins to get more active. As high pressure builds over the Northern Plains and Midwest, southeast Texas will be on the southern periphery of the high, meaning the door to Gulf moisture will be wide open.

The clockwise flow around high pressure basically allows anything underneath to move east to west, so this strong upper level storm system over the Deep South will act as an enhancement for thunderstorms Monday and Tuesday. While the strongest “forcing” with this disturbance will go north of Houston, the combination of this, a stalled weak front, and a bunch of Gulf moisture will likely produce pockets of heavy rainfall that could lead to flash flooding early next week. The eastern part of the area is in a slight risk (level 2/4) for flooding risk on Monday, and it’s likely this will be expanded or pushed into Tuesday for us.

I would expect some level of our flood scale to go up for Monday and Tuesday, probably Stage 1, maybe Stage 2. Eric will have an update for you on Monday morning, possibly Sunday if our confidence is high.

Things should quiet down some after Tuesday, with perhaps even a couple days off from rain chances. This does mean temperatures should begin to heat up with mid-90s by later next week, and possibly a bit hotter by the weekend. Stay tuned.

In brief: Smoke and dust creating a hazy situation around Houston this weekend will likely continue into early next week. But also a slight change will allow for some minor rain chances to return after the weekend.

The weather in Houston can only be described right now as very typical late June or July. It’s hot and humid but not overly so. We have already seen some Saharan dust, but we’re also seeing a lot of haze aloft that is almost certainly related to ongoing Western U.S. wildfires.

This acrid looking mix of smoke, dust, and haze will persist through the weekend, only accentuated by a burst of Saharan dust by later Sunday or Monday.

Today & weekend

Not a whole lot of change in things expected here, with sun, heat, humidity, and haze. Saharan dust thickens up a bit as Sunday progresses. Shower chances are minimal. That’s about it. We’ll keep it simple today.

Next week

As we head into Monday and Tuesday, a sprawling area of upper-level high pressure is going to establish itself over the Ohio and Mississippi Valleys, bringing a pretty hefty heat wave to parts of the Midwest, Mid-South, and East Coast. Houston will be positioned on the southwest periphery of that high pressure. For us, that does a couple things.

First, it should open the door to the Gulf a bit. This will allow for the typical splash and dash summer thunderstorms we get here in Houston to re-enter the picture by Tuesday or Wednesday. Second, it will allow for the Saharan dust plume to blow into the area early in the week. Smoke from the western wildfires should hopefully diminish some. Also, it means that if any tropical waves enter the Gulf, they could be pointed toward the Gulf Coast. By Wednesday or Thursday, that’s a possibility, and although development of any significance is not expected, it could help nudge up our rain chances a little for the middle to end of the week. Or it could mostly end up in Louisiana. Both are reasonable potential outcomes. We’ll watch this weekend to see how things go.

Either way, by our 250th birthday next weekend, we’ll probably see that Gulf connection back off a bit as high pressure shifts out of the Midwest, with somewhat hotter, drier weather returning to Texas.

Drought update

The rains of late have definitely done wonders for our drought situation in Texas. Most of the state is now free of drought, with the notable exception of the Panhandle and portions of northeast and interior central and south Texas. The last time the majority of Texas was free of “abnormally dry” or worse conditions was September of last year.

Lake Corpus Christi is about 33 percent full now, up from 14 percent a month ago. While Choke Canyon is still in very poor shape (below 10 percent full), the other reservoirs are picking up the slack and buying some time before what will hopefully be a wetter winter in South Texas. We shall see.

In brief: After yesterday’s ridiculously high humidity in Houston and across southern Texas, we start to think about more rain chances this weekend. We’ll start to dry out a bit more next week, with a return of hotter weather and standard Houston mid-summer.

In the storied history of Texas humidity, yesterday was a first ballot hall of fame day. “But it’s always humid and hot in Texas.” Yes, that is the case from June through September. However, statistically, yesterday was on another level. Let’s start with Houston. I went back and looked at hourly observations from Bush Airport going back to the 1970s. Yesterday ended up being the 12th most humid day on record there. How am I defining “most humid?” It’s the daily average of dewpoints. The higher the dewpoint, the more humid or oppressive it is.

I was surprised to see that one day last summer (August 26th) actually beat it out by a tenth of a degree. The most miserable stretch of humidity on record in Houston had to be June 2019, with dewpoints averaging near 80 degrees.

Now, if you change the location, you get some different results. For instance, at Hobby Airport (where hourly records only go back to 1996), it still ended up being the second most oppressive day on record.

While actual air temperatures weren’t too crazy, the combination of this humidity, in some cases way inland also produced some extreme heat outcomes. Maximum heat index values hit 110° in Galveston and College Station, 112° in Waco, Tomball, and Sugar Land, 113° at Bush and in San Antonio, 114° at Hobby, 118° in Austin and Brownsville, 120° in Bay City, and 122° (not a typo) at Corpus Christi. That Corpus heat index has only been hit on seven prior occasions back to 1948. Their all-time record heat index is 125° on June 17, 2023.

So no, it was not your imagination; yesterday was near maximum tier humidity for the Houston area, and much of Texas for that matter. The cause obviously has something to do with Arthur and the recent surplus of rain we’ve received. But I am assuming it’s pretty nuanced, with some degree of those influences as well as a warm Gulf contributing. I think that the Arthur influence is tenuous, however. Typically, winds behind tropical systems come out of the north or northwest, which actually lowers the humidity a little but allows temperatures to skyrocket (dry air heats up more efficiently than humid air). Yesterday saw winds out of the south or south southeast. I have to think the warm Gulf and recent rains and saturated soil were the primary causes.

Onward.

Today

I wish I could tell you today would be a little less oppressive, but I cannot. At least not for the morning. Dewpoints remain in the upper 70s and low-80s across the area this morning. Thus, heat index values are already in the lower 90s in most spots. As the day goes on, we’ll probably see humidity values drop just a little, which is enough to keep us in Heat Advisory conditions today rather than yesterday’s Extreme Heat Warning. Heat index values will probably peak a couple degrees lower than on Thursday.

Additionally, we could see some rain today, which would help the heat out. Today’s higher rain chances are north of I-10, especially as you get up toward College Station, Conroe, or Lake Livingston. That said, we could see a few storms fire off in the Houston Metro as well. Any storm today could again produce torrential rainfall for a short period of time and localized street flooding.

Saturday

We should cool off a little more on Saturday thanks to some added cloud cover and rain chances. Saturday’s specific rain forecast is a little tricky, but scattered thunderstorms are likely across the entire area. This means not everyone will see rain, but many folks should. Yet again, locally heavy downpours are a possibility. Look for highs around 90 and heat index values probably another 1 to 4 degrees lower at peak than today.

Keep the heat in mind, especially if you’re participating in the Oranje Fanwalk for the World Cup or heading to the events in EaDo (and elsewhere).

Sunday

The end of the weekend should begin to transition us back to more typical summer weather. Look for isolated to scattered thunderstorms, with less coverage than Saturday. High temperatures will be in the low-90s with typical Houston heat index values in the low to mid 100s.

Next week

It would seem that next week will step us up into standard Mid-summer weather here in Houston. High temperatures each day should be in the low to mid-90s.

Morning lows will be generally around 80, give or take a couple degrees. And rain chances will be low but not zero.

In brief: Hot, humid weather stays in Houston through Sunday before a return to a much stormier weather pattern Sunday night through Tuesday. Heavy rain is a good bet, along with the potential for some flash flooding during that time.

Yesterday was 93° here in Houston. Just a reminder to folks, especially with so many added events happening across town due to the World Cup: Stay hydrated (with water) and wear sunscreen. Early season heat is always a bit extra stressful on the body because we have not entirely acclimated to it yet. And with a lot of people doing a lot of not-typical early summer things, it can weigh on you. We just want to add in that note to remind folks of that as summer makes itself comfortable here.

Today & Saturday

Much like we’ve seen the last couple days, you may run into an isolated downpour at any point during the day. Nothing organized is expected to impact the area, but you may want to have an umbrella at the ready, just in case. We’re probably looking at about 91 to 93 degrees both days for highs.

Sunday

Deep tropical moisture will begin to pool over Texas later tomorrow and then especially Sunday and Monday. As these moisture levels increase, so too should the coverage of showers.

We don’t expect much of anything organized Sunday, but there will probably be somewhat greater coverage of downpours across the area. For those attending Germany vs. Curaçao or taking part in any of the festivities around town, just have an umbrella handy. Highs will be near 90 degrees.

Sunday night through Tuesday

The combination of tropical moisture off the Gulf, as well as an approaching “cool” front is likely going to lead to an outbreak of numerous downpours and thunderstorms across Texas, including in the Houston area. Our region has already been placed under a slight risk (level 2/4) for excessive rainfall and flooding risk for Monday.

Most areas should pick up a solid 1 to 2 inches of rain from this. We do expect there to be pockets of higher totals right now, above and beyond 3 to 4 inches, but it’s tough to say exactly where those are most likely. (Here? Louisiana? Both?) But this is something we will watch and update you on Sunday about. I would expect us to probably issue a Stage 1 or 2 flood alert, but we’ll see what the data shows through Sunday. Manageable but perhaps an inconvenience at times.

Either way, expect Monday to be close to a washout and perhaps Tuesday as well. Temperatures will struggle mightily as a result, with highs probably only in the mid-80s at best on those days.

Rest of next week

We should begin to dry out from the heavier rains Wednesday and Thursday, but the pattern still looks a bit unsettled. Temperatures should begin to warm up again, back to the low-90s by the weekend.