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.

In brief: Houston faces three days of widespread showers, with the potential for heavy rainfall and street flooding, before conditions start to ease heading into the weekend. The entire metro area lies under a Stage 1 flood alert through Thursday, although the potential for heavy rain this week is highest near the coast. That’s where we expect the greatest accumulations, with 6 or more inches possible in some locations.

Tuesday

Showers have developed near the coast this morning, at sunrise, and are making their way inland. Coverage of these storms may widen for areas south of Interstate 10 this morning, and this may prove impactful during the morning commute. Some street flooding is possible. Later today we can expect widespread showers for much of the area, with embedded heavy rainfall through the daylight hours. Please be weather aware as you get out and about today.

The coverage and intensity of showers today should wane as we get toward sunset, but some light to moderate rain will still be possible overnight. Highs today will get into the mid-80s for most locations, although far inland area (with lesser rain) may reach 90 degrees. Winds will generally be light, from the east, at 5 to 10 mph. Lows tonight will drop into the mid-70s.

Wednesday and Thursday

These days will both see widespread coverage of moderate to heavy rainfall, with the highest totals likely along and south of Interstate 10. Most of our modeling continues to paint coastal areas, from southern Brazoria County to Galveston Island, and up the Texas coast to Port Arthur with the greatest accumulations. Heavy rainfall is certainly possible for areas further inland, such as Katy, Tomball, The Woodlands, or Kingwood, it’s just that widespread coverage is less likely. In any case, be prepared for travel delays during the heaviest storms; but also understand that not everywhere is going to see heavy rainfall nor serious impacts.

Rain totals through Thursday night should be on the order of 2 to 4 inches for areas north of Interstate 10, with higher end totals of 6 inches or greater possible south of Interstate 10 and especially along the coast. We should also continue to see quieter nights in terms of storm coverage.

Heavy rainfall remains the big threat this week, with the possibility of damaging winds and other severe impacts much lower. Highs both days should be in the low- to mid-80s for most locations. Evening temperatures will be, dare I say, almost pleasant?

Friday, Saturday, and Sunday

Rain chances remain high for the weekend, albeit with less coverage and storm intensity with each passing day. By Sunday or so, only about half of Houston is likely to see rain, and accumulations should be modest. Daily highs will correspondingly rise from the mid-80s on Friday into the low-90s by Sunday.

Next week

By Sunday or Monday, we’ll start to feel the encroaching high pressure from the eastern United States. This will lead to sunnier days—we can probably expect mostly sunny skies most of the time next week—and warmer temperatures. Highs will likely start out in the low-90s next week, but I suspect we’ll be in the mid-90s by the second half of the week as we enter August. Rain chances are not going to go away entirely, but they’ll be greatly diminished, and likely to only occur during the afternoon along the sea breeze. Summer is going to summer in Houston, as it does in August.

In brief: Houston will see high rain chances through the coming weekend, but the threat of heavy rainfall will be particularly acute during the next four days. We have issued a Stage 1 flood alert for now through Thursday, which indicates the potential for street flooding. Basically, you’ll need to pay attention to the weather this week.

A wet pattern

As we discussed on Sunday, the overall setup for this week favors moderate to heavy rainfall, with the potential for some street flooding. The upper Texas coast will lay beneath a trough in the upper atmosphere, and our atmosphere will be laden with moisture. Tuesday and Wednesday look to have the most favorable setups for heavy rainfall, but chances will remain high from now until Thursday.

In terms of overall accumulations, I think the Houston area will pick up between 2 and 6 inches of rainfall this week. My biggest concern lies near the coast, with access to the most moisture from the Gulf of Mexico. This is where we could see some bullseyes above 6 inches of rainfall this week. To account for the threat we’ve issued a Stage 1 flood alert for the entire region, which produces street flooding. We’re closely monitoring the situation to determine whether we need to elevate this to a Stage 2 flood alert for coastal counties.

In Houston, roads are designed to flood during heavy rainfall. This is annoying, but in a generally flat region prone to heavy tropical rainfall, roads become arteries by which water is carried into streams and bayous, and thus eventually out into the Gulf of Mexico. So during intense rainfall, roads will briefly back up. This is why we repeatedly stress to not drive into high water. The bottom line is that, this week, we will need to be weather aware. Check the radar before you leave. At this point we don’t anticipate significant home and business flooding, but the heavy rains will likely cause some inconveniences. We’ll be here to try and pinpoint the times of greatest threats. If warranted, we will post multiple updates a day.

Monday

Of the next four days, Monday likely presents the least threat of widespread, heavy rainfall. The chances today actually look best along the coast, from Matagorda to Galveston Bay; and inland, from Montgomery County northward. The most likely scenario is that each of these boundaries remain far enough apart that the central Houston region, including downtown, remains relatively quiet today in terms of rainfall.

However, there is a slight chance the boundaries meet over downtown, near Interstate 10, in which case things would become more active over the central Houston area. Like I said above, keep a good radar app like RadarScope handy. Generally I think things will quiet down this evening and overnight. Highs today will reach about 90 degrees, or so, given the extent of rain-cooled air at your location.

Tuesday and Wednesday

Both of these days should bring waves of moderate to heavy showers through the Houston area. The first of these could arrive some time on Tuesday morning, pushing from south to north, and afterward we should see additional impulses with consistently high atmospheric moisture levels. With mostly cloudy skies, these days should see high temperatures only in the 80s—a remarkable contrast to last year when we were consistently hitting 100 degrees in late July. Overnight lows will be in the mid-70s.

We’ve had some questions about severe weather, and while we can’t rule out some high winds in stronger thunderstorms, generally the wind, hail, and tornado threats will be quite low this week. Our major concern will be heavy rainfall, and rates above 2 inches per hour that can quickly back up streets.

Thursday

We’ll remain in a very wet pattern on Thursday, but forecast models indicate that the impetus for the highest rainfall rates will back off a bit. Regardless, expect widespread showers, with highs in the 80s. At this point we’re planning to expire our Stage 1 flood alert on Thursday night, but we’ll of course be monitoring this closely.

Friday, Saturday, and Sunday

Elevated rain chances will remain through the weekend, but the threat of heavy rainfall should continue to diminish. If you have outdoor plans, I would have a backup plan. Daily rain chances are on the order of 60 or 70 percent, with mostly cloudy skies. Expect highs in the upper 80s to about 90 degrees.

Next week

Rain chances diminish further next week and we’re likely to see a sunnier pattern. As this happens, expect our highs to return to the mid-90s. I don’t mean to terrify or threaten anyone by saying this, but the month that comes after July in Houston is August. And well, August is the worst month of the year as we can expect heat in abundance, and the tropics to become active again after this mid-July lull.