Matt Lanza

Friday night might be soggy in spots

Eric and I just wanted to provide a quick update to you tonight because the forecast has been a little tricky here.

Most of today has gone as expected. But the warm front that was supposed to hang around or south of I-10 into tonight has lifted a bit further north than expected, and is currently approximately straddling US-59. It also hit 80 degrees at both Hobby and Bush (81) today. The air mass over us is plenty conducive for heavier rain at times. That said, radar shows scattered showers and storms west and north of Houston as we told you would be the case this morning.

Scattered showers and storms are rumbling along west of I-45 this evening. (GR Level 3)

Some of this rain is fairly heavy. Thankfully, everything is moving along at a healthy clip so far, so it won’t rain too hard in any one location for too long.

The forecast from this morning deviates a bit from this point into the first part of Saturday. There have been some indications from various weather models this afternoon and evening that some areas around and southwest of Downtown Houston would see repetitive rounds of showers and storms through the night. The latest version of the HRRR model shown below also indicates this to some extent.

The HRRR model from late this afternoon shows some repetitive shots of showers and storms this evening and overnight in the Houston area. (Weather Bell)

Earlier runs of this model were a little more bullish on rain, but nonetheless, you get the idea.

So what does it mean? Neighborhoods primarily south of I-10 and west of I-45 stand the risk of seeing a few rounds of heavy rain and thunderstorms this evening and overnight. Rain amounts could be locally impressive in spots, on the order of 1-3″ (most of us will not see that much rain). If everything moves any slower than we expect right now, 4-5″ of rain could be a possibility in a neighborhood or two.

At this point, Eric and I don’t see serious flooding concerns tonight. Localized street flooding is always a possibility in the Houston area, but we just want you to be aware of a slightly wetter forecast in the region than perhaps was expected. And with folks out and about on a mild Friday night, we want you to know that some area football games could be dealing with some rain or lightning delays. If something changes to make this any more serious over the next few hours, we’ll let you know. But, again, we don’t feel that will be the case.

Cloudtober marches on

After a disappointing end to the Astros season, we could use a little sunshine around here to perk us back up a bit. Unfortunately, there’s not a lot of great news looking ahead. We just offer thoughts on the forecast; we don’t control the weather. But we apologize nonetheless.

Today

Today will be another day of clouds and perhaps a couple sunny breaks in spots if you’re lucky. For those of you that missed warmer temperatures, you’ll be seeing some of those return today too. We crested into the 70s in Houston early yesterday afternoon, and we are already running about 10 degrees warmer than yesterday morning (mid-60s). So we’ll probably push the upper-70s today.

Radar as of 5:30 this morning showed heavy rain in spots from Matagorda Bay south to Corpus Christi Bay. (College of DuPage)

There will be a chance of showers and storms virtually anywhere at anytime, but as radar shows, the heaviest rains are likely to stay south of Houston. The Matagorda Bay region has seen the steadiest rains, but so far most places have only seen a quarter to a half-inch or so. As we go into this afternoon, the focus for the best rain or storm chances may shift to west or north of Houston.

Weekend

Our next cold front is in line to cross through the area later Saturday afternoon or evening. Expect a mild, somewhat muggy Saturday morning, with AM lows in the 70s south and east of Houston and mid-to upper-60s north and west. We’ll probably have scattered showers tonight into Saturday morning across the region. Not everyone will see rain though. As the front approaches during the afternoon, we will have another shot at some showers. I am not too impressed by the dynamics of this cold front as it approaches our area, so I am not terribly worried about any significant weather as it passes by. Rain chances will trend toward zero on Saturday night finally.

Most of the Houston area is expected to see a half-inch or less of rain this weekend. By Sunday evening, some areas toward Central Texas or down around Matagorda Bay may see over an inch of rain. (NWS Houston)

Expect temperatures ahead of the front to peak in the mid-to upper-70s south and east. Areas that see an earlier passage of the front north and west of Houston may not get much past the low-70s.

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Back to our regularly scheduled gross late summer weather

Yesterday was nice. It wasn’t perfect, no, but it’s a start on our road to autumn. Unfortunately, like many Houston freeways, the road there is still under construction. More on that in a second. First, some news.

NOAA has completed their analysis of rainfall return period in Texas. Those maps we’ve utilized for 100 and 500 year floods are now officially obsolete. In the Houston area, a 24 hour rainfall of around 13″ used to be required to classify a rainfall event as a “100-year flood.” Remember a “100-year flood” is a flood that has a one-percent chance of occurring in any given year. That 13″ rainfall has been revised up to 18″ of rain in 24 hours to qualify as a 100-year flood. Basically, what we used to define as a 100-year flood is now a 25-year flood. I think most of us knew this already; it had been telegraphed last year, but we can now make it official.

Why is this changing? The previous maps are decades old. The primary reason is that we have more data and better data to work off of. We also know, based on plenty of data, that rain events are getting bigger in Texas, and this is especially disproportionately true in the Houston-area. Ultimately, there will be ramifications because of these map changes. Infrastructure is built to these map standards. Floodplain regulations are based on these map standards. These changes have been well-telegraphed since Harvey, so some of this process is already underway. But it’s a slow process, so don’t expect changes next month. It’s a start, however.

On to the weather…

Today

Radar is mostly quiet this morning, though we are beginning to see a few showers near the coast as of 5:30 AM. More noticeably, we still see a good deal of cloud cover in the area.

A satellite loop shows low clouds (white), mid-level clouds (yellow), and high clouds (dark colors) moving through the area this morning. Sunshine will be at a premium, especially southeast of Houston today. (College of DuPage)

On the loop above, the bright white indicates lower stratus clouds and the darker colors indicate higher cirrus clouds. The yellow offshore indicates showers and mid-level clouds. Bottom line: We have a lot of clouds around, so sunshine will be limited today, especially south and east of Houston.

As the day goes on, we expect to see scattered showers and storms develop, initially near the coast and spreading a bit further inland as yesterday’s cold front begins to return as a warm front. Look for high temperatures today to hit the low-to mid-80s.

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Dreary, unsettled weather returns to Houston

After a few days off, unsettled weather returned on Thursday, bringing some folks over three inches of rain. Others saw nothing at all, but everyone is likely in line to see at least some rain over the next couple days.

Today

Radar isn’t too active this morning with a few scattered showers — mostly light or occasionally moderate rain.

Radar shows a smattering of showers or lighter rains across the area this morning. (College of DuPage)

As we go into the rest of today, look for scattered downpours and thunderstorms to blossom from later this morning into this afternoon. Like yesterday, we could see locally heavy rainfall in the most persistent storms. Rain amounts will again vary wildly, with some folks seeing little to no rain, while others could see two to four inches in a relatively short time, along with some localized street flooding.

Saturday & Sunday

Unfortunately, the specifics surrounding the forecast this weekend are going to be difficult to lay out. If you’ve lived in Southeast Texas for any length of time, you know that our rain often follows a pattern of feast or famine: Neighborhoods that get soaked may be adjacent to dry neighborhoods. Trying to predict where and when it’s going to rain this weekend is impossible to do more than a few hours in advance, but we know that both Saturday and Sunday carry high chances that it will rain for a period of time during the morning or afternoon hours.

Specific rain amounts will vary significantly from place to place through Sunday evening. On average, expect an inch or two, with some places seeing more and others less. (NWS)

Total rainfall should add up to about an inch to two inches on average across the region by Sunday evening. Some folks will see less than that. Others may see three, four, or five inches of rain or even a little more with some street flooding. If you have outdoor plans this weekend, include an umbrella and an indoor backup if possible. Where the heaviest ultimately falls will depend on how far south a cold front can push, along with other small-scale processes in the atmosphere.

If there’s good news in all this, it’s that our six day string of 90°+ weather should end. We’ll see high temperatures in the mid-80s, with lows in the mid-70s. Yes, it will be unpleasantly humid, but at least it won’t be obscenely hot for later September.

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