Eric Berger

In brief: We’re starting to see a few bands of showers move into the Houston region from a ‘potential’ tropical storm in the Southern Gulf of Mexico. However, as we have observed over the last day or two, the threat of sustained heavy rainfall and flooding in the Houston area continues to decrease. We’re still watching things closely over the next 24 hours, but we don’t anticipate major problems in the metro area.

Airports and severe weather

Let us begin this post with question: My wife is flying into Bush Intercontinental Airport on Wednesday shortly after noon. Do you think her flight will be canceled with the storms?

It turns out this is a trick question! The wife in question is actually my wife. She really is flying into Houston tomorrow. Matt and I frequently receive questions regarding air travel and inclement weather, and I totally get the anxiety. However, neither of us are aviation meteorologists nor pilots. Unfortunately, we don’t have any special expertise or insight into the decision-making at airports that lead to flight stoppages, nor the cancellation of flights. We try to be helpful, but we’re never going to be able to give you the certainty on this issue that readers want. So I’ll give you the same answer I gave my wife: Probably not. Maybe. But probably not.

Before jumping into the post, I want to take care of a couple of housekeeping notes. If you’re wondering how to find us via email, our free app, or social media channels, please find all of those details here. Secondly, while this tropical system is increasingly unlikely to have serious weather consequences for the Houston area, that is not necessarily the case for southern Texas and Mexico. For more information about those sites, please check out The Eyewall. And finally, please find a brief message from our sponsor, Reliant, at the end of this post. Their support helps keep us online, and free for all.

Tuesday evening and Tuesday night

I anticipate that we’ll continue to see on-and-off showers and thunderstorms across the Houston metro area through this evening and during the overnight hours. Based on current model trends and radar activity, some of these showers may be briefly heavy, but we’re not seeing the kind of training storms that will lead to significant or widespread flooding. Some coastal areas may pick up 1 to 3 inches this afternoon and tonight, but most of us will see less than this.

Wednesday

Some time on Wednesday morning, possibly during the pre-dawn hours, more organized storms should move into the Houston area from the coast. Traveling from east to west, some of these showers may bring bursts of intense rainfall, and there could be some street flooding. This is a potential issue for the morning commute, especially for locations along and south of Interstate 10. Due to this potential for street flooding, we are maintaining a Stage 1 flood alert for the Houston region.

By Wednesday afternoon I think shower activity will start to become a bit more sporadic, but the potential for tropical rainfall will remain in place through the evening hours.

Rest of the week

We’ll transition to a pattern of more scattered showers on Thursday and Friday. Rain chances aren’t going to go away, but I also don’t think we’re going to be at any great risk of flooding. The gusty winds we’re experiencing today should persist into Thursday morning, by which time the “potential tropical cyclone” should move into Mexico.

Needless to say, we’re watching the evolution of these storms closely, and if there’s a change in our thinking we’ll post promptly.

A message from Reliant

Thanks to Eric and Matt for keeping us informed during this week’s tropical system and potential impact. We want to remind readers that Reliant stands ready to support Texans and help prepare. Here are a few things to keep in mind as we move through storm season:

1. Reliant’s Storm Preparedness Checklist is a good place to start when thinking through what you need in place, like an emergency kit, go bag and communications plan with loved ones.
2. Be prepared in case of an electricity outage. Your utility company (like CenterPoint in the Houston area or AEP for Corpus Christi) maintains the power lines, utility poles and electricity infrastructure necessary to deliver the power you purchase from Reliant to your home. Contact your utility company to report an outage or check the status of the repair.
3. Check out more preparedness tips and recovery resources at ReliantStormCenter.com. The site provides resources for before, during and after a storm, including preparedness checklists and evacuation routes, weather and power outage updates, flood maps, safety tips and more.

Just like the summer heat, storms are a part of life in Texas, so being prepared is critical. Reliant is proud to power Space City Weather and help bring this important resource to Houstonians and our neighbors.

In brief: While tropical rainfall is still bound for the greater Houston area later on Tuesday and Wednesday, we now believe the worst of it will remain south of the city. Accordingly, we have lowered our flood alert to Stage 1 for the metro area, which is consistent with street flooding.

As a tropical system in the southern Gulf of Mexico has gotten slightly better organized during the last day or so, we’ve been able to observe its rain bands in real time. This has given us confidence in our forecast for heavy rainfall potential in Houston, and changes in model trends during that time. The bottom line is that we now believe the threat of widespread, tropical rains in Houston has lessened. For this reason we are lowering our flooding alert to Stage 1, which remains in effect through Wednesday.

We are now confident that the worst of the system’s rains will go south of the Houston area, perhaps near Matagorda Bay and likely in the Corpus Christi area over the next couple of days. (We’ll be continuing to provide information about this threat to Texas on our companion site, The Eyewall). That’s not to say the Houston area will not see rain, it’s just that we no longer expect the potential for 6 to 10 inches across widespread areas. Rather, while there may be some isolated, significant flooding, for the most part things look manageable.

In terms of timing, this morning looks fairly calm, and I expect the radar to remain mostly quiet through around noon. However, from Tuesday afternoon through Wednesday afternoon, I do expect storm like conditions to develop. Here’s what we can expect in the Houston region in terms of rain, winds, and seas.

Rainfall

For areas along and north of Interstate 10, accumulations of 1 to 3 inches are likely, with higher isolated totals. For locations further south, accumulations of 3 to 6 inches are likely, with higher bullseyes. The areas of greatest concern are southern Brazoria County and points further south, closer to Matagorda Bay. Overall, the risk remains the threat of high rainfall rates due to the nature of tropical moisture. Again, just to underscore this, I don’t think we’ll see widespread flooding in Houston over the next day or two. However, you should be prepared for some disruptions on roadways.

Winds

Starting later this morning winds will increase from the east to about 20 mph, and gusting up to 30 mph. These winds will be even stronger along the coast, and south of Houston, where some gusts may reach up to 40 mph. These strong winds will likely persist through much of Thursday.

Coastal flooding

We may see tides a couple of feet higher due to the storm, especially on Wednesday. This will lead to the flooding of some low lying areas along the coast and Galveston Bay. In addition there will be strong rip currents in the Gulf. Seas will be rough.

With mostly cloudy skies, high temperatures on Tuesday and Wednesday should remain in the 80s for most of the Houston area. Unfortunately, for many, it looks to be a soggy Juneteenth holiday.

Thursday and Friday

Our atmosphere will remain somewhat unsettled toward the end of the week, and each day will have a decent chance of showers. But the threat of consistently heavy rain should be over by Thursday. Skies will be partly sunny on both days, with highs of around 90 degrees.

Saturday and Sunday

Rain chances won’t entirely go away this weekend, but they’ll be lower each day, likely on the order of 20 percent or so. We’ll also see mostly sunny skies, pushing highs into the low 90s at least.

Next week

Overall, next week should looks fairly typical for late June. I think we’ll see highs in the low- to mid-90s, with at least some low-end potential for rain each day. I’m not expecting anything too organized, but sea breeze showers may definitely be a thing. We’ll see.

Our next update will come later this afternoon.

In brief: We’re continuing to track the potential for heavy rainfall in the greater Houston area due to a tropical system in the southern Gulf of Mexico. Whether or not it becomes Tropical Storm Alberto, the effects will be the same for Houston. We now think the period of Tuesday afternoon through the middle of Wednesday will have the highest chance for heavy rainfall.

On Monday afternoon the National Hurricane Center said it would begin issuing forecasts for a “potential tropical cyclone” in the southern Gulf of Mexico. This is the tropical system that we’ve been talking about for several days now. This action indicates that hurricane center forecasters believe the system is likely to become a tropical depression or storm (it would be named Alberto) in the next day, but it has yet to do so.

In truth, this changes virtually nothing about the forecast for elevated easterly winds, higher seas, and heavy rainfall that Houston will experience over the next couple of days. The purpose of this post is to attempt to set some expectations in terms of timing of the worst of the rainfall. Tropical weather is inherently unpredictable, but now that we’re closing in on Tuesday and Wednesday, our confidence is a little bit higher. Emphasis on a little.

Monday evening and overnight

As expected we’ve seen scattered showers and a few thunderstorms today, and generally I expect this pattern to continue this evening and overnight. These storms should pose no threats for flooding risks beyond putting a damper on outdoor activities.

Tuesday

Generally, I expect Tuesday morning will not bring anything too crazy in terms of sustained heavy rain. However, by around noon or shortly after that it appears a deeper slug of tropical moisture will move inland into the upper Texas coast. This is when we expect the development of more widespread showers, especially along and south of Interstate 10. The heaviest rain is likely to fall closer to the coast, because that is the source of the moisture. It is too early to say whether heavy rainfall on Tuesday afternoon and evening will impact commute home, but it’s a distinct possibility.

Tuesday night and Wednesday

Our modeling continues to suggest that the heaviest rainfall will arrive later on Tuesday, and persist through Tuesday night through much of the day on Wednesday. By Wednesday evening or night, it does appear that the the worst of the rains will be exiting to our west.

I’m hesitant to speak about accumulations with too much certainty. There continues to be a lot of noise in the models about what to expect. There are some scenarios in which the bulk of the heavy rainfall goes south of Houston (and Galveston) on Tuesday and Wednesday. In this case the region (even coastal regions) might pick up only a handful of inches of rainfall—totally manageable.

However, I would rate as slightly more likely the possibility that the southern half of the Houston region picks up 4 to 8 inches of rainfall through Wednesday, with higher isolated amounts. This, obviously, would create some flooding issues and is the reason why we’ve instituted (and maintained) a Stage 2 flood alert for the entire region through Wednesday.

The thing with tropical rain is that it comes in bunches. And with this system, we have the very real possibility that at least some portions of our area will see sustained tropical rainfall during the next 48 hours. So please be prepared for that possibility.

Our next update will be posted early on Tuesday morning.

In brief: Our pattern is changing this week with arrival of tropical moisture. This will lead to heavy rainfall over the Houston area, especially on Tuesday and Wednesday. However, our concerns for Houston are lower today with much of our model guidances now projecting the most extreme rainfall further south, near the Coastal Bend and areas such as Corpus Christi.

Tropical moisture arriving

A surge of tropical moisture will move into Texas this week. However, based upon trends in the forecast over the last 24 hours, the threat of the heaviest rainfall has shifted south of the greater Houston region, including Galveston Island. This does not mean it is not going to rain in the Houston area this week. However, it does mean that our risk of seeing extreme rainfall totals and widespread flooding is lower.

For the time being we are going to maintain a Stage 2 flood alert for the Houston area through Wednesday given that the potential for high rainfall rates remains. Localized areas, especially near the coast, are still likely to see flooding. However, a Stage 2 event for Houston can now be considered a worst-case risk scenario.

Monday

A large area of low pressure in the far southwestern Gulf of Mexico is starting to push a surge of moisture toward Texas this morning, and we’ve already seen some streamer showers. Atmospheric moisture levels will rise today, and as a result this afternoon I anticipate seeing fairly widespread showers and thunderstorms. A few areas could quickly pick up a couple of inches of rain, but totals for most locations should be less. Rain chances will slacken a bit tonight. With partly to mostly cloudy skies, highs today will be in the upper 80s for most locations.

High seas, high winds

Beginning today we’ll also see increasing winds from the east due to the low pressure system. These will peak on Tuesday and Wednesday. While they won’t be too significant for much of the area—we are talking gusts of up to 25 to 30 mph—they could be higher along the coast, including Galveston Island. A coastal flood watch is also in effect for this week, with tides likely to run a couple of feet higher than normal, and a high risk of rip currents. Low-lying coastal areas may flood.

Tuesday and Wednesday

These days will see the highest threat for heavy rainfall, as tropical moisture levels peak in the atmosphere. As noted above, a majority of our modeling now indicates that the greatest potential for heavy rainfall—that is, the areas where we could see 12 inches or more of rainfall—are now south of Houston, in locations such as Matagorda Bay and Corpus Christi.

That does not mean that Houston is out of the woods, so to speak. The environment is still favorable for heavy rainfall this week, it’s just a bit less favorable. In terms of expectations, much of the area along and north of Interstate 10 is likely to see between 1 and 5 inches of rain this week, with areas south of the freeway and closer to the coast likely to see 3 to 6 inches. The risk, for coastal areas, is that localized areas could see higher amounts. That remains possible given the state of the atmosphere. And high rainfall rates can quickly backup streets.

Highs on Tuesday and the Juneteenth holiday are likely to be in the low- to mid-80s due to cloudy skies and the likelihood of rainfall.

Thursday

Rainfall remains possible on Thursday, even likely. But as moisture levels start to decrease, so too will the threat of heavy rainfall. Look for highs in the upper 80s with partly sunny skies.

Friday, Saturday, and Sunday

We should see the return of partly to mostly sunny skies for the weekend, with highs in the upper 80s to lower 90s. However, as high pressure is unlikely to be in total control, each day may well have a decent chance of afternoon shower and thunderstorm activity with daytime heating. We’ll see.