In brief: The rest of this week will see the potential for storms in the Houston region, and as of right now Wednesday looks to have the most widespread activity. Due to the possibility of heavy rainfall within stronger thunderstorms, and the cumulative effect of multiple rounds of rainfall, we have put a Stage 1 flood alert in place for this week.

Unsettled pattern

As we’ve been discussing on the site, Houston remains in a pattern where the absence of high pressure leaves us open to passing atmospheric disturbances. We will continue to see these systems sweep through our region every 18 to 24 hours or so, bringing a chance of widespread showers and thunderstorms. Not everyone is going to get hit with storms every day, but the threat of heavy rainfall and lightning is going to be part of our weather story at least through the weekend.

We can count on daily rain chances of 50 percent, or higher, through Sunday. Due to the potential for isolated flooding with each round of of showers, and the cumulative effect of all this by the weekend, we have put a Stage 1 flood alert into place until further notice. This is to cover the potential for (mostly minor) street flooding issues.

Tuesday

The radar is quiet this morning, and I expect things to likely remain quiet until around noon. However, after that there is about a 50 percent chance of showers and thunderstorms, with perhaps the best chances in the central Houston area and to the far north of the metro region: i.e. Conroe and points north. Skies will otherwise be partly sunny with highs in the low- to mid-90s. Actual highs will depend on the timing and coverage of the rainfall. Winds will generally be light, except in thunderstorms. Lows tonight will be in the upper 70s with a slight chance of rain.

There is a slight chance of “excessive rainfall” on Wednesday in our region. (NOAA)

Wednesday

High resolution models are indicating that a particularly potent disturbance will sweep through on Wednesday. I’d put rain chances in the 70 or 80 percent ballpark, with a slight risk for excessive rainfall. The timing is tricky, but right now the most impactful rains and thunderstorms are likely to fall during the middle of the day. Highs will probably top out in the vicinity of 90 degrees.

Thursday, Friday, Saturday, and Sunday

Overall the pattern is not likely to change much over the second half of the week, and into the weekend. Days will be partly cloudy, with highs in the vicinity of 90 to 93 degrees, with plenty of humidity. Each day will bring perhaps a 50 to 70 percent chance of rain, with isolated, strong thunderstorms. If you have outdoor plans, there’s a chance you can squeeze them in, as it certainly will not be wall-to-wall rain. But you probably want to have a backup plan.

Next week

This overall pattern now seems likely to extend into the middle of next week, perhaps through about Tuesday or Wednesday, before we see more sunshine and warmer temperatures, along with a diminution in rain chances.

In brief: Good afternoon. Matt and I have seen enough data to put a Stage 1 flood alert into place beginning today, and to remain place until further notice. In truth we can probably expire it Wednesday or Thursday, but we want to see how the pattern evolves before setting an end date.

Essentially, with high pressure having departed, the region now lies open to a series of disturbances that will bring rounds of showers into the region for much of this week. The first of these can be expected later this afternoon and into the early evening, and the next one after that by either late morning on Tuesday or into the early afternoon. Then we will continue to see the potential for additional rounds of showers, thunderstorms, and potentially severe weather (perhaps hail) for a couple of more days.

The threat level here is not super high. But with this Stage 1 flood alert we want to call attention to the possibility of intermittent heavy rainfall that may briefly back up streets and lead to some mobility issues. Not everywhere is going to see rain every day, or as every round passes through. However, with each passing system there are likely to be some pockets of heavier rain, and we want you to take a little extra time and care in such storms.

We will, of course, have a comprehensive update on all of this Tuesday morning.

In brief: Temperatures in the Houston region soared into the upper 90s this weekend, but with the departure of high pressure our atmosphere has now been cracked open to storm activity. There will be a healthy chance of showers and thunderstorms all week, which will help keep a lid on temperatures.

Weekend heat

The city of Houston did not set heat records this weekend, but we came close and the temperatures outside offered a preview of what we can expect later this summer. The record highs for both Saturday and Sunday were 99 degrees (set in 1903 and 1980, respectively), and we hit 97 degrees on Saturday and 98 on Sunday at Bush Intercontinental Airport. Combined with humidity and warm nights, it felt like deep August out there. Alas the climatological ‘peak’ of summer heating in Houston is still about two months from today. Now, at least, a reprieve.

Monday

A line of storms is advancing upon the Houston region from the north, and as of sunrise it is moving into the central metro area. These storms are relatively slow-moving, and will work their way through the city and down to the coast by around noon. We are not seeing too much in the way of severe weather with these thunderstorms, but they could certainly produce some ponding on roadways and cause some brief street flooding issues.

Skies should clear out later this morning, and this should allow high temperatures this afternoon to push into the low- to mid-90s. With this daytime heating we may, in turn, see the development of some additional showers and thunderstorms this afternoon or early evening in central Houston. Lows tonight will only drop into the upper 70s.

Tuesday, Wednesday, and Thursday

This period should see unsettled weather. In the broader picture, with high pressure having departed, a series of disturbances will produce healthy rain chances each day. Again, we cannot entirely rule out the possibility of some damaging winds or other severe weather, but the primary threat during this period will be the potential for heavy rainfall.

Overall, I think this will be manageable, with most of the area picking up between 1 and 3 inches between now and Thursday. But this is Houston, we’ve reached summer, and there is always the potential for heavy rainfall that briefly backs up streets. This is a function of a) living near a very warm body of water in the Gulf of Mexico and b) living in a relatively flat city where it takes time for tropical rains to drain. But I don’t expect it to rain all the time, and some locations probably will not see rain some days.

Daily high temperatures will be dependent up cloud cover, and when and how much it rains during the afternoon hours when it typically is hottest outside. But each of these three days should see highs in the vicinity of 90 degrees, with some locations a bit above, and others a bit below. Although daytime temperatures will be a bit cooler, humidity will be plenty high, and you know those nights will be warm and muggy.

Friday

Skies should turn a bit more sunny as we get toward the weekend. Expect highs in the lower 90s. Rain chances will still be decent however, at least 50 percent for much of the area.

Saturday and Sunday

Daily rain chances remain on the menu this weekend, probably about 50 percent each day. Overall accumulations should be quite a bit lower this weekend, i.e. I think the potential for street flooding will diminish. Probably. Expect highs generally in the lower 90s, with partly sunny skies. Nights will only fall into the upper 70s.

Next week

This overall trend should persist into next weekend; that is temperatures probably will remain the lower 90s with a decent chance of showers each day. If you’re bummed about the rain, I get it. But this is the kind of pattern that really helps set our region up nicely for the typically hot and dry patterns we can get locked into in July, or August, or both.

In brief: Thunderstorms impacting the Dallas-Fort Worth Metroplex and Abilene may hold together overnight and arrive in Houston near sunrise, bringing thunder, lightning, and locally heavy rain to parts of the area.

We’re barging into your Sunday evening briefly to just offer a heads up that thunderstorms may arrive in the Houston area on Monday morning. In North Texas, there’s a pretty potent severe weather risk tonight. We’ve seen gigantic hail in the area between the Caprock and the Metroplex. Those storms are now kind of congealing into a complex of thunderstorms that will continue to arc east and southeast, possibly arriving in Southeast Texas by Monday morning.

While we are not under severe weather risk tonight, there is a marginal risk posted for Monday (level 1/5) for Houston. These storms could hold together a bit as they approach. While we do not expect gigantic hail or extreme winds like they’ve seen in some spots up north, we could see some frequent lightning, gusty winds, and heavy downpours.

The HRRR model depicted above shows storms arriving right around 6 AM before dissipating by 8-9 AM. Don’t focus on specifics but rather the overall picture which shows a gradually weakening line of storms moving in. The most likely area to see organized thunderstorms is north of I-10 and west of I-45, but it’s possible that many of us see at least some rain or thunder by mid-morning Monday. Conditions would then calm down a bit Monday afternoon.

Bottom line: Don’t be shocked if you’ve got kids or pets running in a little before wake-up time tomorrow. We’d currently rate this about a 6 out of 10 on the excitable dog scale, with perhaps some higher values up toward Navasota or Huntsville or Conroe.

Eric will have more in the morning.