Lots of rain this week in Houston, but probably not widespread flooding

Sunday marked the beginning of a surge of tropical moisture into Houston, and Monday represents the second day of what is looking like a four- or five-day stretch of wet weather for the region. The good news is that, despite the soggy conditions we anticipate, right now it doesn’t appear as though we are going to see extremely high rainfall rates that will cause significant flooding. Our best guess for conditions through Thursday, therefore, is sporadic street flooding. If you’re wondering how this affects your activities, it should be business as usual in Houston for the most part. (And if you’ve scheduled an outdoor birthday party, you have our apologies).

Monday

The radar shows scattered, moderate showers streaming into the Houston area this morning, but the heaviest rainfall remains offshore. That should change later this morning and into the afternoon, as a tropical disturbance moves closer to the Texas coast, and inland tonight. We anticipate the greater Houston region will see 1 to 3 inches of rainfall today, with the potential for higher localized amounts under the most intense storms. As you can see in the map below, rain totals will likely be greater near the coast.

NOAA’s 24-hour rain accumulation forecast for 7am Monday through 7am Tuesday. (Pivotal Weather)

Given these conditions, we do not anticipate widespread problems due to rainfall, however if you find yourself in a heavy downpour, the most dangerous thing you can possibly do is drive into high water. Please, don’t do that. Wait a little while, as these storms should progress through the area fairly rapidly and any flooding should be temporary.

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A wet Monday in Houston: Here’s what we know, and what we think

Sunday has gone about as expected—with a smattering of heavy downpours but most of the region receiving 1 inch of rain or less. Monday and possibly Tuesday will almost certainly be different, with the potential for widespread heavy rainfall, and enough uncertainty that we’re going to continue to watch the forecast closely. We will have an update on the site no later than 6am CT Monday.

What we know

The heaviest rains are remaining well offshore over the Gulf of Mexico as of Sunday evening. The general expectation is that as the tropical disturbance moves west, toward the Texas coast, these showers will slowly move toward Texas and southern Louisiana as well.

HRRR model forecast for 7pm CT Sunday showing storms mostly offshore. Click this file to animate for a forecast through Noon, Monday. (Weather Bell)

This inland movement of heavier storms seems most likely to happen sometime on Monday morning, but whether that’s shortly after midnight or well into the day, we can’t say for sure. I’d guess after sunrise, if I had to.

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Rain showers coming to Houston Sunday through Tuesday

Welcome to the weekend, everyone. We’ll be updating the site both on Saturday and Sunday out of an abundance of caution, rather than because we’re particularly concerned about the potential for flooding this weekend. The overall story remains the same: heavy rain potential increases on Sunday and Monday, with the biggest threat some localized high rainfall rates. As Houston floods go, this is not likely to be a memorable one.

Average of rainfall forecasts from the European ensemble model for now through Tuesday. (Weather Bell)

Saturday

The weekend will start out mostly sunny, with a high in the low 90s on Saturday. Rain chances should increase later today, with 30 to 50 percent chances near the coast, and lower chances inland. Because moisture levels won’t spike until Sunday, we don’t anticipate any concerns from heavy rains. If you have outdoor plans today, I’d press ahead.

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Houston weather this weekend—be wary but not too worried

Please allow me a few words of reflection this morning before we get to the forecast. (It really hasn’t changed much—2 to 4 inches of rain for much of the area, with the potential for greater amounts possible in some locations. We have some concerns, which we discuss below, but don’t anticipate major, widespread problems at this time).

Amazingly we have been talking about the rainfall for “this coming weekend” for nearly a full week. This began late on the afternoon of Friday, June 8, when a couple of local forecasters looked at the GFS operational model (re-posted below) and called attention to the fact that it showed a hurricane moving into Texas on Sunday, June 17. I was taking a family vacation at the time, but received several messages from readers concerned about this, so I asked Matt to write about it. He authored an excellent update titled, “Yes, we saw the Friday PM GFS model; we aren’t stressing.” This kind of perspective is precisely why we started this site.

The GFS model run last Friday showed a hurricane hitting Texas this Sunday. Oh noes! (Tropical Tidbits)

What concerns me is that we have now been writing about this event for a week, and there is a non-trivial chance that for much of Houston this will not be more than a few significant thunderstorms. This sort of rainfall does not warrant the amount of attention it has received. And if Houston does receive the 2-4 inches of rain over a few days that we anticipate, it will degrade public confidence in meteorology as the hype will not match reality—i.e. the boy who cried wolf. I understand that people are highly sensitized after Hurricane Harvey, but every storm is not Harvey (or even close). So I just wanted to reiterate what I wrote at the outset of hurricane season“Social mediarology” plays on the fears of people, and therefore tends to get shared widely. If you’ll promise to not fall for these kinds of fear-mongering posts, we’ll make a pledge to you: If we believe there is a credible threat to Houston, we will report that immediately. And if we haven’t written about it, the post you’ve seen on Facebook is probably garbage. Fortunately we have a sponsor like Reliant, which doesn’t value clicks, but rather reliability. Now, on to the forecast.

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