Editor’s note: On July 29, 2025, we published a new version of the Space City Weather Flood Scale. The new version incorporates research done by two psychologists at the University of Houston, Steven Paul Woods, Psy.D. and Natalie C. Ridgely, Ph.D. We intend the new version to be more user friendly and helpful in the time of a storm. In this post, Drs. Woods and Ridgely explain the research they did to inform this update. And here’s a link to the official news release from the University of Houston.

How can we help Houstonians better prepare for major weather events?

An impassioned tweet from Matt about the challenges of weather communication during the 2022 hurricane season led us to wonder: Can we use psychological science to help Houstonians better understand and prepare for major weather events? We posed this question to Matt, who was enthusiastic about the potential of a meteorology-meets-psychology research collaboration. Matt and Eric were specifically curious if we could boost the usefulness of the beloved Space City Weather (SCW) Flood Scale (Lanza & Berger, 2023).

The original goal of the SCW Flood Scale was to help Houstonians better understand and prepare for a wide range of flooding events. The SCW Flood Scale uses a color-coded numerical rating system (1 green = nuisance street flooding to 5 red = severe life-threatening flooding) and provides a historical flooding event for context (e.g., Hurricane Harvey). But does it nudge people to actually prepare for flooding? This is important because even when people know the flooding risk of an approaching storm, they may not turn that knowledge into useful ways to protect themselves (i.e., weather-protective behaviors). There are meaningful gaps between what we know, what we intend to do, and what we actually do (e.g., Fishbein, 1979). Providing people with direct informational cues can help bridge these gaps (Grounds & Joslyn, 2018; Woods et al., 2022). So, we designed a simple experiment to see whether including examples of appropriate weather-protective behaviors at each level of the SCW Flood Scale helps people do a better job of planning for storms.

How did we do this study?

The Storm Forecasts: With Matt and Eric’s help, we created three realistic storm forecasts that varied in severity on the SCW Flood Scale (i.e., Stages 1, 3, and 4). We presented these storm forecasts to people in a randomized order.

The Weather-Protective Behaviors: After hearing the three storm forecasts, participants were asked to rate their intentions to do 12 different weather-protective behaviors on a scale of 1 (unlikely) to 5 (very likely). Higher scores mean stronger plans to practice useful weather-protective behaviors. We included actions that would be helpful in a flood, like reducing the amount of time spent on the roads, gathering necessary supplies, charging electronic devices, and listening for emergency alerts. We also included actions that sounded reasonable, but may not be helpful during a flooding event, like wrapping exposed pipes, securing the foundation of their home, or sheltering in a basement.

The Experimental Groups: The study participants were randomized into one of two groups: 1) A control group who saw the standard version of the SCW Flood Scale; or 2) A weather-protective cue group who saw a new version of SCW Flood Scale that included examples of weather-protective behaviors at each level of flood risk (e.g., Stage 1 = Consider reducing time on the roads; Stage 3 = fuel vehicles; Stage 5 = identify safe evacuation routes).

The Study Participants: We recruited 100 healthy adults from 5 Gulf Coast states to participate in this study. Importantly, the control group and the weather-protective cue group did not differ in demographic factors (e.g., age, education), cognitive ability, weather literacy, and experience with storms.

Did the experiment work?

In brief, yes! People in the weather-protective cue group did a better job of planning for the storms. Figure 1 shows the flood-protective behaviors on the vertical axis, where higher scores mean better plans to practice useful flood-protective behaviors. The individual storm forecasts are on the horizontal axis. You can see that the benefits of the protective cues varied by storm severity. The flood-protective cues had strong benefits for the most (Stage 4) and least (Stage 1) severe storms, but only weak benefits for the Stage 3 storm, which was a fast-moving wind event for which flood protective recommendations may be somewhat less clear. Encouragingly, we also found the largest benefits of the flood-protective cues among people who had the lowest levels of baseline weather preparedness. That means we were able to improve flood-protective plans for the people who were at greatest risk of being unprepared. Finally, we found that the flood-protective cues had no effects on non-beneficial actions (e.g., wrapping household pipes). In other words, the flood-protective cues only nudged people towards doing things that are known to be helpful for their health and property during a flooding event.

What’s next?

The results of this simple experiment suggest that adding flood-protective action cues to the SCW Flood Scale increases the likelihood that people will plan to safeguard their home and health in response to flood forecasts. We are excited that Matt and Eric will be working with Reliant to add the flood-protective cues to the SCW Flood Scale moving forward. And we hope that this new version of the SCW Flood Scale will provide additional support and comfort to Houstonians as they prepare for future storms. We are currently looking at whether the benefits of the flood-protective cues vary across people who may be particularly vulnerable to weather impacts, including older people and those with serious medical conditions. We are also curious to learn more about what leads people to choose non-beneficial weather-protective actions in these situations. Finally, we would like to know whether we can help Houstonians better understand and use heat warnings. So, stay tuned for more meteorology-meets-psychological science!

Steven Paul Woods, Psy.D. and Natalie C. Ridgely, Ph.D.
Department of Psychology, University of Houston

References

Fishbein, M. (1979). A theory of reasoned action: some applications and implications. Nebraska Symposium on Motivation, 27, 65–116.

Grounds, M. A., & Joslyn, S. L. (2018). Communicating weather forecast uncertainty: Do individual differences matter? Journal of Experimental Psychology: Applied, 24, 18–33. https://doi.org/10.1037/xap0000165

Lanza, M.R. & Berger, E. (2023). The Space City Weather Flood Scale: An imperfect attempt to help a flood-weary region put rain forecasts in context [abstract]. Paper presented at the 103rd Annual AMS Meeting, Denver, Colorado, USA.

Woods, S. P., Morgan, E. E., Loft, S., Matchanova, A., Verduzco, M., & Cushman, C. (2021). Enhancing cue salience improves aspects of naturalistic time-based prospective memory in older adults with HIV disease. Neuropsychology, 35, 111–122. https://doi.org/10.1037/neu0000644

In brief: In today’s post we reveal the new design and content for our flood scale. We have made changes based on research conducted by the University of Houston. Although rain chances will increase later this week, we also anticipate no need to use the new flood scale any time soon.

Updated flood scale

This morning we are pleased to announce an update of our flood scale, which is intended to help guide expectations for people in the greater Houston region when it comes to the potential for flooding. We first introduced our flood scale in 2019, after Hurricane Harvey, and have used it dozens of times since then. But we really did not understand how people were using it.

Now, with the help of some researchers from the University of Houston, we do. A professor of
Psychology, Steven Paul Woods, reached out to Matt a couple of years ago, and together they and one of his doctoral students, Natalie C. Ridgely, worked to perform a study of the scale and whether it was effective at communicating risk. Later this morning we will publish a summary of the study, and its results, written by Woods and Ridgely. (Here it is).

As a result of this study, we have made some changes in the structure of the scale to simplify it, and added recommended actions. Reliant provided a cleaner design. What thrills me the most is that this scale was created here in Houston, and improved by local researchers who care about this community just as much as we do. It is by Houston, for Houston.

Our new scale appears below:

Tuesday

Well, we won’t need the flood scale today. With high pressure firmly in place, Houston is going to have one of its hottest days of the year. With sunny skies, look for high temperatures to push into the upper 90s across most of the region away from the immediate coast. Some inland areas may reach 100 degrees. Winds will be very light, from the west mostly. Lows tonight will only drop into the upper 70s.

Wednesday

This will be another hot and mostly sunny day, with highs in the upper 90s. However there will be a couple of subtle differences. One is that dewpoints may drop into the mid-60s across the region. This is not “dry” in any great sense, but these dewpoints are lower than normal for this time of year. So humidity will be lower than we have been often experiencing this summer, especially for inland areas. There also will be a very slight chance of showers later on Wednesday afternoon or evening.

Thursday and Friday

Low pressure stretching across the Gulf will bring increased rain chances into the area for several days. On Thursday and Friday the likelihood of rain will be somewhere between 30 and 50 percent, with low-end accumulations for most. Depending on the timing of rain (if any) highs will vary between the low- and upper-90s, with partly to mostly sunny skies.

Saturday and Sunday

Better rain chances will arrive this weekend, with both days bringing about a 50 percent likelihood of showers. For now we don’t see too much of a risk for really heavy rainfall, and my expectation is that most locations will pick up between 0.25 and 0.5 inch of rain. Since this is summer and tropical rainfall is possible, we’ll be on the lookout for higher totals, but for now this looks more like a splash of rain rather than a deluge. Highs will generally be in the low- to mid-90s with partly sunny skies.

Next week

The first full week of August does not look to be excessively hot. Temperatures probably will be in the mid-90s for the most part, with a smattering of daily showers driven by the sea breeze. Beyond that, we shall have to see.

In brief: Today’s post discusses the historical depths of summer, which occur over the next two weeks. However, while we will see considerable heat the next couple of days, increasing rain chances should help to take the edge off summer heat through the weekend.

Depths of summer

Look, it can be really hot in Houston any time from April through October. And historically we have seen 100-degree weather as early as June 2, and as late as September 27. But the very warmest period of the year, based on climate statistics, comes from July 29 through August 12. This is when the region’s high temperature averages 96 degrees. By August 13, the average high drops to 95 degrees, and by the end of the month we’re down to 93 degrees. So we’re here, at the peak of summer in Houston.

And do you know what that means? If you squint, you can see fall in the distance.

Monday

After several rounds of showers over the weekend, which included some flooding just east of downtown Houston, our weather will now quiet down for a few days as high pressure builds over the area. We will see that in the form of sunny skies today, with high temperatures in the upper 90s for inland areas, and lower 90s for coastal areas. With that said, I would not entirely rule out of a few scattered to isolated showers later this afternoon or evening along the sea breeze. Winds will be light. Lows tonight will be sultry, and in the mid-70s.

Tuesday

This will probably be the hottest day of the week, with sunny skies and high temperatures in the upper 90s for most of the region. However, dewpoints look to be slightly lower, so while the humidity will be high, it may not be oppressive. Rain chances are near zero. Expect another warm night in the mid-70s.

Wednesday

At this point I think high pressure will still largely influence our weather on Wednesday, so we can probably expect mostly sunny skies and highs mostly in the upper 90s. At the same time, we are going to see growing amounts of tropical moisture pooling to our east out over the Gulf, and this will bring higher rain chances during the second half of the week. So maybe we should splash in a low-end chance of a few showers.

Thursday and Friday

Skies will still probably be partly to mostly sunny to end the work week, with high temperatures generally in the mid-90s. However, as low pressure (the risk of this becoming a tropical depression or tropical system is near zero, so we’re not particularly concerned about that) drifts toward Texas across the Gulf, it will bring increased moisture levels into the coast. This will likely yield rain chances of about 30 to 50 percent for both days.

Saturday and Sunday

We should remain in this pattern of elevated rain chances through the weekend, with a 50 percent likelihood of showers each day. At this point I don’t expect the weekend to be a total washout, and there still should be periods of sunshine on both days. But temperatures should be a couple of degrees cooler (some areas may top out in the lower 90s). Overall accumulations look fairly modest. Most of the area may see something on the order of 0.5 inch of rain, but there probably will be higher bullseyes. All in all, for the peak of summer, it won’t be terrible as Houston moves into August.

Next week

I think we will see a continued chance of showers on Monday and perhaps Tuesday before things high pressure asserts a little more control next week. However, at this point I think we’re likely to remain the 90s rather than pushing up into the 100s.

Tropics

Things look very quiet out there for the next week or so, and quite possibly beyond. This is a great position to be in as we edge toward the month of August. Longtime residents will know that the next two months are, traditionally, “go time” for Texas and the tropics. So we will be watching things very closely.

In brief: Periods of rain and scattered thunderstorms will be with Houston today and tomorrow as a disturbance moves in from the Gulf. Then, we will get another round of heat heading into next week, peaking on Wednesday or Thursday.

Today

The tropical disturbance with 10 percent development odds that we’ve been discussing all week is on final approach to the Texas coast. The NHC pegs it just south of Vermilion Bay in Louisiana. On radar, we’ve clearly got a few showers across the area. There is a more robust area of rain closer to the disturbance itself that’s moving westward over the Gulf.

As the day goes on, look for that area of rain to move toward Galveston and/or Freeport. Inland areas will see quick moving downpours at times. Once the disturbance comes ashore tonight, there could be periodic downpours and even some thunder. Some areas will see little to no rainfall. Other places could pick up a quick inch or so in heavier downpours. I do think coastal areas may see a steadier rain later today, and thus they could see up to 2 inches or so of rain before all is said and done.

High temperatures this afternoon will struggle and may not even reach 90 degrees in many spots. Look for upper-80s to low-90s (if the sun gets out) and a bit more humidity than we’ve had this week.

Saturday and Sunday

This tropical disturbance is not slowing down for anyone. By tomorrow afternoon, the fingerprint of the disturbance should be past I-35 and into West Texas. We will still see scattered thunderstorms across the area, with an increase in coverage as temperatures warm up tomorrow.

On Sunday, the chance of rain drops even a bit more, but again not to zero. While Saturday will probably top off in the low-90s, Sunday could be in the low to mid-90s.

Next week

So what’s next? First, we’re going to get a surge in heat once more. Houston should peak in the mid-90s on Monday with a chance of a storm, mid to upper-90s on Tuesday, and upper-90s to near 100 degrees on Wednesday and perhaps Thursday.

After Thursday, it almost looks like yet another Gulf disturbance may enter the picture, though this one could be even a bit farther north (possibly over land) than the current one. No real development risk by any means, but we’ll see if this can’t help enhance shower and thunderstorm chances and lower our temperatures to close out next week.