In brief: Tropical rains brought flash flooding to a belt of the region south and east of the city of Houston overnight, but the worst of these storms is ending. We still have some rainfall concerns this weekend, but we are getting through it. Next week looks sunny and warmer.

As anticipated, we saw a another round of heavy rainfall develop near the coast after midnight, and these storms have dropped a significant amount of rainfall for some areas south and east of Houston. During the last 12 hours, for example, locations such as Dickinson and Baytown have recorded 5 to 7 inches of rainfall, and parts of Pearland and League City have recorded 4 to 6 inches. These heavy rains produced flash flooding consistent with our Stage 2 flood alert for these locations.

The strongest impulse of these storms has now cleared the area, but we are continuing to see some high water locations on streets and feeder roads in parts of Galveston and eastern Harris County. Please take a little extra care heading into work this morning from impacted locations. For the majority of the Houston metro area, overnight impacts were far less significant and there are no issues.

It appears that this was the last mass of truly organized storms for the region, however that does not mean we are done with the rain. We can probably expect fairly widespread showers and thunderstorms to develop near the coast early on Saturday morning and propagate inland. Due to the potential for these storms to hit already water-logged areas, I am going to maintain a Stage 1 flood alert through Saturday noon.

Friday

In the wake of the overnight storms, we’re seeing a fair number of showers and thunderstorms across the Houston metro area. Generally, we should see these storms move toward the northeast later this morning, with things quieting down later this afternoon or evening.

However, we could see an additional impulse of heavy rain right along the coast today, pinpointing locations such as Galveston Island and Bolivar Peninsula. I’m hopeful that these rains will develop to the south of Dickinson, Baytown, and other areas hard hit overnight. But radar trends will be something we should watch today for coastal areas.

For the majority of Houston, however, Friday should be mostly business as usual, with totally manageable accumulations and few impacts. With mostly cloudy skies, we can expect highs to top out in the low-80s. Winds will be generally light, from the southeast. Overnight low temperatures will drop into the 70s.

Saturday and Sunday

We are likely to remain in a pattern whereby we see storms develop during the overnight hours offshore and move inland. However, coverage and intensity should be lower on Saturday morning, and again on Sunday. Still, some isolated locations could see heavy rainfall, and both weekends could see a rainy start—especially south of Interstate 10. If any of this changes, I’ll pop in with a forecast update this afternoon, or over the weekend.

Highs on Saturday should be in the low-80s, with mid- or upper-80s possible on Sunday. As we’ve been saying, this weekend is fairly difficult for outdoor activities, especially anything involving the beach.

Next week

Our pattern shifts in a big way by early next week, with mostly sunny skies likely in place by Monday, and rain chances falling way back. Most of next week should see sunshine, highs in the low- to mid-90s, and give our area a chance to dry out. Pretty soon we’re going to realize that Houston’s highs at this time of year are not usually in the 80s, as we’ve experienced this week.

In brief: With low pressure and plenty of moisture in the atmosphere, expect another wet day for much of Houston. Due to the potential of flash flooding, we are maintaining a Stage 2 flood alert for coastal counties through Thursday night, and a Stage 1 flood alert for areas further inland, including Harris County. This pattern should start to change later on Friday and this weekend. Next week looks sunny.

Thursday

Areas generally to the south and east of Houston have seen 0.5 to 1.5 inch of rain overnight, totals which have mostly been manageable, but which have contributed to waterlogged soils. We are likely to see additional rounds of moderate to heavy rainfall later this morning and into the afternoon hours, with areas closer to the coast continuing to see higher rainfall. For the most part, these showers should be a nuisance rather than a genuine hazard.

However, the atmosphere retains the potential for heavy rainfall through today and tonight. By this I mean some storms could drop 2 to 4 inches per hour, which given our soils will back streets up quickly. Because the potential for these higher rainfall rates is greater near the coast, we are maintaining a Stage 2 flood alert for all coastal counties. Please remain weather aware today, with an eye on the radar. We will update the site this afternoon, if warranted. In this case, no news would be good news.

High temperatures today, due to persistent cloud cover and rain-cooled air, should remain in the vicinity of 80 degrees. This is decidedly not the norm for late July in Houston, and we’ll soon see a turn toward hotter weather. Winds remain light, from the east or southeast, at 5 to 10 mph. Lows tonight will only fall a few degrees from daytime highs.

Thursday night and Friday

Consistent with the pattern we’ve seen in recent days, we may see a lull in showers this evening. However, it seems most likely that we’ll see another round of showers develop near the coast after midnight, and that these will progress northward throughout the morning hours on Friday. I don’t want to jinx anything, but I think this probably will be the last “round” of showers we see from this system as the upper-level low finally lifts out of the area. Accordingly, I expect highs to be a little warmer on Friday afternoon, perhaps reaching the mid-80s.

Saturday and Sunday

Although the threat of heavy rainfall will largely have passed by this weekend, we’re still likely to see mostly cloudy skies with periodic light to moderate showers. High temperatures both days will push into the upper 80s, with a few inland areas possibly reaching 90 degrees.

Next week

Most of next week should yield mostly sunny skies. High temperatures look fairly typical for this time of year, pushing into the mid-90s. At least right now there is not any sign of going much higher than that. In any case, aside from the warm days and humidity, next week should offer a period of relatively calm weather in Houston. Are we allowed to have such things in the year 2024?

In brief: Rain has been manageable so far today. We expect more rain this evening, with scattered heavy downpours. Another round of potentially heavier rain is possible on Thursday morning. We’ll maintain our flood alerts as is for now.

Rain has been mostly under control since this morning thankfully. The next wave is coming ashore now at the coast, and even this one is checking in a bit more manageable than it looked this morning.

Still, rain rates around 1 inch an hour or so are likely as this pushes ashore. As it moves north and east, we’ll see most rain impacts on the southeast side of Houston, with isolated to scattered downpours north and west. Total rainfall will be an additional inch or two at the coast and less inland (except in isolated heavier downpours) through this evening. Any street flooding is expected to be more nuisance in nature.

Looking ahead, modeling is suggesting another rather beefy area of rain and storms approaches the area overnight or early on Thursday morning. This would be capable of perhaps another 1 to 4 inches of rain.

There remains enough uncertainty in the models that we use for these type of rain events that I think maintaining the Stage 2 alert for the coastal areas and Stage 1 inland is the right move. One model we track closely during these events suggests as much as 7 to 10 inches could fall in a worst case scenario between Galveston and Port Arthur and southwest Louisiana. I would especially watch the Beaumont-Port Arthur area in this setup. We don’t expect that outcome, but we can’t rule it out entirely. For the majority of metro Houston and suburbs, another inch or two, with some seeing more and some less seems reasonable.

Eric will update us on Thursday morning with the latest regarding the rainfall.

In brief: Although the coast has largely been spared heavy rainfall for the last two days, it now appears that the axis of strongest storms will shift there on Wednesday and Thursday. Due to this heightened threat for widespread street flooding, we are elevating coastal counties to a Stage 2 flood alert for now through Thursday evening.

Wary of offshore rains

As the Houston region has fallen into a very wet pattern over the last two days, the heaviest rains have fallen north of the city. Some locations in The Woodlands, for example, have received in excess of 9 inches of rainfall, and areas near Kingwood have received 4 to 6 inches. These heaviest rains have been fairly isolated, however, as most of the Houston region has picked up 1 to 2 inches so far.

We have a couple of more days during which the threat of heavy rainfall is high, so what will happen next? The majority of our modeling guidance suggests the threat will shift southward, particularly from southern Brazoria County up the coast through Galveston Island and all the way to Beaumont-Port Arthur. For this reason, we are elevating our flood alert for coastal counties to Stage 2 on our flood scale.

This means that for coastal counties—Brazoria, Galveston, Chambers, Jefferson, and Orange—there is the threat of flash flooding today, tonight, and on Thursday. Under Stage 2 conditions we generally expect widespread street flooding, and the potential for some localized flooding of homes and businesses. For the rest of the Houston metro area, and particularly areas along and inland of Interstate 10, lesser impacts are expected. We are maintaining a Stage 1 flood alert there.

Wednesday

Just before sunrise this morning we are seeing moderate showers across much of the Houston area, and for now these are totally manageable. But there is a line of showers and thunderstorms just off the coast that is more menacing. There is a fairly good chance this line will slowly lift northward into the coast, including Galveston Island, this morning. This will pose a distinct threat to flood streets.

These showers will gradually spread inland today, but based on our latest modeling they should gradually have a reduced impact and weaken some as they do so. Due to widespread showers and mostly cloudy skies, we can expect highs today to top out in the the low- to mid-80s for most locations.

Wednesday night and Thursday

The most likely scenario is that we see a similar pattern tonight. Some time after midnight another line of showers and thunderstorms appears likely to congeal offshore and then push into Galveston, Chambers, and Jefferson counties during the wee hours. This may spark another round of flooding for areas along and near the coast through Thursday morning. These showers should move inland during the daytime, albeit with likely reduced intensity.

All told, most locations south of Interstate 10 should receive at least 2 to 6 inches of rainfall on Wednesday and Thursday. My concern, and the reason for a heightened flood scale alert, is the possibility for some of these storms to dump 10+ inches of rainfall right along the coast. The models are increasingly highlighting this threat for places such as Galveston Island and the Beaumont-Port Arthur area.

Friday, Saturday, and Sunday

The threat of very heavy rainfall should end by Thursday evening or so, but that does not mean our wet pattern will end. Rather, we’ll continue to see a healthy chance of showers through the weekend. We don’t expect to see the kinds of storms that will produce significant flooding, but there look to be fairly widespread showers. If you have outdoor activities planned, especially for Saturday, I would not feel great about them.

Highs for this period will range from the upper 80s to lower 90s, with partly to mostly cloudy skies. There is a chance of some sunshine by Sunday afternoon, however.

Next week

As high pressure starts to build into the area, next week should be hotter. Starting Monday, I expect we’ll reach at least the low-90s, and by midweek I expect Houston to be solidly in the mid-90s with lots of sunshine. We cannot rule out a stray shower here or there along the sea breeze, but these should not result in any serious accumulations.

We will have an addtional update later this afternoon or early evening to keep tabs on the situation.