Matt Lanza

In brief: Another smattering of downpours is likely today, however, it will probably favor the southern fringe of Houston (Galveston/Brazoria Counties). Much calmer weather begins tomorrow, along with less humid weather thanks to our cold front as well. It still looks hot, but it will be much more tolerable at times, especially in the mornings.

Yesterday saw some impressive rains resulting in some street flooding and a flash flood warning near and just southeast of downtown Houston. Rain totals over 3 inches are plotted below.

We had just shy of 6 inches near 45 and the South Loop, just shy of 5 inches at Hirsch and Tidwell, and over 3 inches on the University of Houston campus. Overall, it was quite an active afternoon.

As for today, we’ll probably take down the Stage 1 flood alert we put in yesterday by this evening. There will still be downpours around today, and I think areas south of I-10, particularly down near Galveston or in Brazoria County will have the highest odds of some localized street flooding. Just a heads up for anyone returning from the coast from the holiday weekend.

Otherwise, look for intervals of sun and clouds with highs generally in the upper-80s to low-90s.

Rest of this week

A rather tranquil early September week awaits Houston. In terms of thunderstorms, other than an isolated one tomorrow, it looks like our next real chance at showers will wait til the weekend. Our first “front” of autumn is here now, and this about as good as we can hope for in the first week of September. We will actually see daytime highs increase this week, owing to a combination of fewer storms and drier air. In fact, by Thursday or Friday, we could be pushing the upper-90s again. But that drier air means it will be less humid than usual for the first week of September.

Less humid air should also translate into mornings that feel half-decent; not cool by any means but quite tolerable. A few locations on the outskirts of the metro area should see lows in the 60s I would imagine by Wednesday or Thursday morning. Overall, I’m not sure you could realistically script a much nicer week to open September with!

Another cool front is going to try and approach again later this week. This one will have limited luck in pushing through, but this could again reinforce the somewhat drier air mass over Texas early next week as well.

Tropics

The tropics continue to look calm in the Gulf. There is one area with (at least) a 40 percent development chance in the Atlantic, but this one will take a few days to get moving and is over a week out from the islands, not a concern for the Gulf at this point.

We have about 4 to 5 weeks of peak Texas hurricane season remaining. The first one looks good. Fingers crossed.

In brief: We are pushing out a Stage 1 flood alert for today based on developments since this morning. Locally heavy downpours will almost certainly cause some street flooding around the area, primarily of the nuisance variety, so use caution the rest of the day if out and about.

Update: The flash flooding threat has mostly ended. We will go back to normal, ending the flood scale alert and referring you to our Friday AM post for the weekend outlook.

We’re going to update things today, as it appears we’ve got some sluggish movers out there. We’ve already seen a couple flood advisories this morning, and some chunks of the area have received 1 to 4 inches since Tuesday.

As such, we’re going to fire up the flood scale for Stage 1 today. I would bank on at least a few areas seeing flooded streets today that may inconvenience travel as the afternoon wears on. So, use caution out there today, particularly in areas of persistent downpours. Off and on rain and thunder is likely to persist and maneuver around the area through early evening before hugging the coast at times again overnight, possibly spreading inland a bit again as well.

So use caution out and about, and we’ll let you know if things should escalate further, though we don’t believe that to be so today. Our next update will be planned for Saturday morning unless the situation warrants otherwise.

In brief: Another round or two of showers and storms will pelt many parts of the Houston area today, with some locally heavy rain possible. Rain chances will start to slow this weekend into early next week before the next round of rain chances kicks off around midweek. There are no current tropical concerns for the Houston area.

Yesterday’s storms were relatively squirrely, especially down in Brazoria and southern Fort Bend Counties. There was a 66 mph wind gust reported from a CenterPoint weather sensor at Brazos Bend State Park. Fascinatingly enough, the radar looked rather innocuous with the storm at the time, but some strong wind gusts elsewhere, including nearly 50 mph just west of Damon seem to back that reading up. That’s just the thing with storms this time of year in Houston: If you catch one at the wrong point in its life cycle in the wrong way, it can produce some pretty quick, short-lived but nasty impacts.

Today

Already today we’ve seen plenty of thunder and some wind gusts up near 50 mph near San Luis Pass. As of this writing, the heavier storms are all offshore, with some isolated downpours and lightning outside the Beltway in western Harris County back through Sealy and Columbus.

As the day goes on, we may actually see things calm down a bit for a time before ramping back up again this afternoon or this evening. I’m not entirely confident on the timing of the next wave; some modeling is quick and quite aggressive with coverage of the next wave of showers as early as late morning. Others hang development back until late afternoon. But we do know a second wave of scattered downpours is likely later today. Expect a very sporadic pattern of coverage with some places seeing squat and others seeing as much as 2 to 3 inches in short order.

Weekend

A continued chance of showers and thunderstorms will be with us on both Saturday and Sunday, as is typical for August. We do think coverage and some of the intensity of the storms will wane a bit on both weekend days, with perhaps Sunday having even less coverage than Saturday. We may see another rude early wake up in spots on Saturday morning as some nocturnal storms could pop up after midnight between Houston and the coast. Then I think we’ll see a summer pattern of mid to late afternoon isolated to scattered downpours resume.

Look for highs in the mid-90s, with a few isolated upper-90s possible.

Monday and Tuesday

We think things will be similarly subdued like Sunday to start next week. Rain chances certainly are not zero, but they’ll remain lower. Highs should again be in the mid-90s.

Midweek next week

We should see another boundary drop in or develop over the region around midweek next week. This should mean an increase in shower and thunderstorm coverage once again. Look for cooler daytime highs as a result.

Total rainfall between today and next week is likely going to be around 1 to 3 inches near the coast, with lesser amounts inland. Isolated higher amounts are possible anywhere in the area, and yes, some isolated places will see lower amounts too.

Tropics

The map currently favors us for the most part.

Of the activity out there today that we’re monitoring, only Invest 99L is worth keeping an eye on. No reliable model guidance is bringing it to the Gulf, but just out of respect for the calendar and history, it’s important to just check in and see if southern tracking waves like this one heading for the Caribbean can survive enough to get closer. Even if it were to do that, I’m not sure that the upper pattern would allow it to come north much, if at all. So either way, this probably ends up buried in Central America ultimately. But we’ll babysit it anyway. Other than that, you can continue to assume the brace position as we navigate the final 5 to 6 weeks of our peak hurricane season. We’re all just trying to get to the finish line.

In brief: Invest 98L, the Gulf tropical disturbance, will bring an enhanced chance of showers or storms to Houston today and Saturday, but nothing much more than that. After that exits, we maintain typical August weather with heat, humidity, and daily shower and storm chances.

Today/Invest 98L

First off, let’s get the elephant in the room taken care of: Invest 98L, the tropical disturbance approaching the South Texas coast is becoming less likely to develop now, particularly because it’s quickly running out of runway to work with. Odds remain 50% per the NHC, though if it does develop, it would be a tropical depression for about 3 to 6 hours or less before reaching land in South Texas.

That being said, it looks somewhat interesting on satellite this morning, conversationally at least.

This may look a little scary, but in reality, there is no low-level circulation so while there are some heavy thunderstorms and heavy rain underneath this blob of clouds, the system is not organizing much. So you can disregard any meaningful tropical development (wind, coastal flooding) elements of this for the most part.

What we will watch for at least is rain.

We don’t expect a ton of storms here today. But as this blob of storms lifts toward the coast, watch for development coinciding with daytime heating from Matagorda Bay up through Galveston, quickly moving inland. The one thing that will probably limit flooding is that storm motion today looks pretty quick. Unless we end up seeing several storms in a row over the same area, expect a few places to see perhaps an inch or two in less than an hour, some quick, minor street flooding, and then hopefully calmer weather. It’s possible that we also see a localized stronger storm with gusty winds as well.

Overall, the impacts of the tropical disturbance should be for a slightly more active August afternoon today. Even on slightly active days, some neighborhoods may not see any rain at all, so that’s possible too.

It’s extremely humid outside this morning as some of that added moisture works into the area. We had some of our warmest overnight lows of summer in some parts of the region yesterday, and we’ll be close to matching or exceeding them today (Jamaica Beach has not fallen below 86 degrees as of this writing for example).

Saturday

With the tropical disturbance dissolving inland, we’ll be left with added moisture and onshore flow Saturday. For now, I’d say this is pretty typical August weather, but I wouldn’t be entirely shocked to see a few repetitive thunderstorms that cause some minor street flooding tomorrow. Otherwise, just look for high humidity and warm to hot temperatures in the 90s.

Sunday & Monday

We should see relatively calm weather here, with just a continued slight chance of afternoon thunderstorms. Coverage should be a little less than it will be today and Saturday however. Highs in the mid-90s.

Rest of next week

High pressure is going to flex and expand in the Rockies and central Plains. This should open the door to some rain and thunderstorm chances out of Louisiana into southeast Texas, combining with sea breezes in the area to keep us somewhat active. Look for mid-90s continuing.