Matt Lanza

For some folks, today is the coolest morning in months! Crockett, for instance, is down into the 50s. IAH, at least as of 6 A.M. has not gotten under 70 just yet.

We will see if we can match our cool day of the week (69° on Wednesday) or even sneak just below it before the sun gets up. Either way, it’s comfortable out there today, and we’ll be closing the week on a very high note. Enjoy it, because things will begin to change in earnest later this weekend. We detail the situation below. Look for a post later today that will set our initial Flood Scale expectations for next week.

Today

No issues whatsoever. It’s beautiful. Enjoy it if you can. We will see highs peak in the 90s with abundant sunshine and rather comfortable humidity.

Saturday

While Saturday morning won’t start off quite as cool as we are this morning, it should still be a pleasant start to the day, with morning lows ranging from the 60s inland to 70s near the coast. There is even a chance that Galveston checks in cooler tomorrow than it did today. Look for more sunshine, highs in the 90s, and perhaps just a tinge higher humidity.

Sunday

The end of the weekend will bring the beginning of our transition into the wet period we’re expecting. I would expect at least a chance of thunderstorms in Houston and south of I-10 with increasing clouds elsewhere. Morning lows in the 70s will warm into the upper-80s or low-90s depending on how much sun you see. No serious problems are currently anticipated Sunday, but if you have outdoor plans, keep the rain chances in mind.

Next week

So let’s talk about next week. There are a number of factors that will go into exactly how next week plays out, some of which are rather low confidence still today. But in general, expect increasing rain chances Sunday through Wednesday, with locally heavy rainfall and potential for at least some flash flooding concerns, especially south and east of Houston and along the coast. Let’s walk through some of the players and how they will influence what happens next week.

First, the primary reason next week looks wet: High pressure over us today will leave us to the east over the weekend, steering Gulf moisture back into the area. The remains of our cold front offshore transition to what we call a surface trough. And then you may add a tropical system to the mix in northern Mexico or far south Texas. You can see this all reflected on a forecast surface map below.

Confidence is relatively high that the high pressure area will move to our east and open the door to Gulf moisture. So that much we know. Where confidence drops is in relation to possible tropical development off the Mexico or Texas coast.

Odds have been increasing that whatever moves into the Bay of Campeche this weekend will develop into a tropical depression or weak tropical storm. That’s one thing we have moderate to high confidence in: That this system has a rather low ceiling in terms of intensity. It should track along the coast and north, probably making landfall in northern Mexico or far south Texas on Monday sometime.

This will matter some, however because the exact location of the track and how well organized this disturbance is will help dictate where the highest rain chances are located and how high the totals will be. These situations are not straightforward. Sometimes you’ll see the heaviest rain hug the coast or just inland and cause flash flooding problems. Other times the heaviest rain will fall offshore and end up mostly harmless for coastal communities. We just don’t know at this point exactly what it will look like.

Here’s what I think we can say right now, with some level of confidence:

• We will have periods of thunderstorms beginning later Sunday and continuing into Tuesday or Wednesday of next week.
• It won’t rain the entire time, and there may be some substantial breaks in the rain, especially north of I-10.
• Rain will likely be heavy at times however, especially along the coast and possibly south or east of Houston.
• Localized street or flash flooding is possible, especially south and east of Houston, but it is too soon to tell you exactly where and when that may occur.
• Rain totals of 2 to 6 inches on average for most of the area between Sunday and Wednesday, with the highest totals in smaller pockets south and east of Houston, perhaps up to 8 to 10 inches or even more.
• While tropical development is becoming increasingly likely, we do not expect this to be a wind or surge issue for us. Some rough seas, rip currents, and elevated tides will be possible, but development should remain weak enough and far enough to our south to avoid the wind & surge problem. This will be almost exclusively a heavy rain situation for us.

Here is the current NWS rainfall outlook into next week.

While some areas will probably see less rain than forecast above, their placement of the bullseye totals south and east of Houston is logical right now, and higher amounts are possible in those areas.

Drier air and lower rain chances should begin to build in after Wednesday.

After we digest the morning weather model data, look for a post from Eric later this afternoon that will initiate our Flood Scale outlook for this event. And we’ll keep you posted over the weekend.

Happy Sunday everyone! We hope your weekend has been going well so far. The weather has certainly cooperated for the most part. The rest of today should behave similarly. We just wanted to post about a couple things since we sort of left the weather situation for the upcoming week on an open-ended note on Friday. We’ve gotten a good bit of clarity over the last couple days, which, as it turns out is good news for us.

This evening & Labor Day

As noted on Friday, we do expect conditions to become a little more unsettled heading toward tomorrow. If we look at a quick surface weather map of the region, we can see the main players. First, we have a weak little trough (orange dashed line) dropping southeast across Texas today. That could focus a few showers and storms tonight, and this would primarily be north of Houston.

The second item to note on that map is an actual cold front. Sadly, this isn’t going to be a classic autumn cold front, but this may be just enough to help lower humidity a little for the week ahead, particularly during the afternoon. Instead of nighttime lows in the mid to upper-70s, perhaps we’ll have a few mornings in the low to mid-70s this week. For those seeking that true pumpkin spice latte weather, this won’t be it, but it will be a start.

More importantly, this front will serve as a focal point for scattered thunderstorms on Monday. I would not be shocked if we have some activity in the morning and then a break with more in the late afternoon. Storms tomorrow afternoon could be on the strong side with locally heavy downpours. Just keep that in mind if you’ll be traveling to or from somewhere or hosting an outdoor BBQ. Probably good to have a backup plan for the BBQ, just in case. Outside of rain, it should again be in the 90s tomorrow.

Tuesday through Thursday

Back on Friday we told you about how models had gotten a little more excited about the potential of a tropical system in the Gulf. For us, some good news: Whatever “that” is should not develop much, and it will almost certainly miss well to our east.

The National Hurricane Center is continuing to assign about 30 percent development odds over the next 5 days from Invest 91L, now emerging in the Bay of Campeche. But the upper level pattern will feature a strong ridge in the upper atmosphere that builds from about Las Vegas on Monday to the Four Corners on Thursday. That eastward expansion of high pressure in the upper atmosphere, combined with a pretty strong trough in the eastern U.S. will likely help deflect the tropical noise into the central or eastern Gulf. This leads our rain chances to drop in the Houston area Tuesday, Wednesday, and Thursday. Obviously we don’t want to see Louisiana face yet another tropical threat, but thankfully whatever does develop here (if anything does at all) should be weak. That said, some heavier rain is possible in the eastern Gulf from this system. As of right now, official forecasts are only about 1 to 4 inches, aimed mainly at Alabama and the Florida Panhandle.

Some locally heavy rain is possible in Louisiana from this, but the primary focus is likely to stay east of there as well. We’ll keep watching, just in case, but we feel fairly good about the upcoming week overall for the Houston area.

Beyond next week: Other tropical threats?

There have been some posts circulating on social media regarding various deterministic (singular) model runs showing a hurricane in the Gulf around mid-month. I’ll be honest, the operational GFS has been quite consistently showing a system (of varying intensity) in the Gulf around mid-month (sometimes in Mexico, sometimes in Texas, sometimes elsewhere). While the GFS ensemble has been, in this forecaster’s opinion, one of the best tools to use in the tropics to identify possible threats the last two hurricane seasons, the GFS operational model still has many flaws. This is especially true on a day 10+ forecast. I don’t care how consistent it has been showing a certain outcome: It is still a day 10+ operational forecast model, and it is *not* meant to be used with any specificity whatsoever. While it’s nauseating to deal with this stuff multiple times per hurricane season, it is the world we presently live in, and so let me be the one to tell you: At this time, you do not need to be worried about the threats shown on operational models that various, mostly anonymous Facebook pages are sharing.

Ensemble support for this system is not zero, but it’s not at a high enough volume yet where I begin getting concerned. And there is absolutely no dominant signal within the ensembles as to where such a system may or may not track even if it develops. Some show Mexico, some show Texas, some show east of here, some (roughly half) show no development at all! We see scenarios like this show up multiple times per hurricane season. Sometimes they lead to development. Often times, they do not. So, could this change? Absolutely, but sitting here today it would irresponsible to pump up the operational GFS model on day 11 without showing the ensembles at the same time which paint a less ominous picture. Let’s talk when it’s inside 7 days and see where we stand. It is the peak of hurricane season, so you should be checking in regularly anyway. But we see nothing exceptional at this very early stage.

Alright, that’s enough for now. Enjoy Labor Day if you’re able, and we’ll come back at you on Tuesday with the latest.

Good evening! One of the things we’re trying hard to do this year is meet more readers in ways that are comfortable for them or they find to be the most useful for getting weather information. We’ve developed an app and started a Spanish language site, spearheaded by Houston meteorologist Maria Sotolongo. With Maria’s background in television, we’re also going to try to provide some more video content when possible. As we head into Labor Day weekend, we wanted to provide you with a quick video update on the outlook for the weekend, the latest on the Gulf tropical mischief next week, and musings about our first fall front.

We certainly aren’t going to pivot away from what we do each day on both the English and Spanish language sites, which is post our morning updates and more frequent updates when it counts. That’s our bread and butter and we know it. And we definitely won’t constantly bombard you with notifications. But we are efforting to reach Houston-area folks in more ways and meet you where you are, so we will experiment with some videos like this from time to time. Please feel free to share your feedback with us in the comments or the feedback link above. I will say that it is great to have Maria here with us, and she’s been full of great ideas to continue serving you!

Just as a quick note: There was nothing earth-shattering about today’s model guidance regarding next week’s potential tropical system in the Gulf. We’re still in wait and see mode, and there is nothing too alarming at this point. But it’s September, so we’ll be watching. Look for a post probably Sunday with the latest. Meanwhile, enjoy the holiday weekend if you are able!

We saw some heavy rain in spots yesterday, with Spring Branch picking up almost 3 inches of rain, while the areas near Addicks, Oak Forest, and just west of The Woodlands saw 1 to 2 inches of rain.

Another mini-bullseye occurred along the Houston Ship Channel in Galena Park, as well as down near Clute in Brazoria County and in Baytown. Basically, you either got a torrential downpour yesterday or you just heard distant thunder. We’ll start the holiday weekend off on a similar note, before we turn mostly dry and hot for a couple days.

Friday

We will probably experience a similar sort of day today as we saw on Thursday. Already, there are some showers along the coast south of Galveston this morning. Watch for isolated hefty downpours across the area, but there’s probably an equal or better chance you see absolutely nothing today. Outside of the scattered downpours it will be sunny and hot. Look for generally mid-90s today with plenty of humidity.

Saturday & Sunday

Both days look primarily sunny and hot. Expect high temperatures in the mid to upper-90s, with a couple spots testing 100° or so. Morning lows will be in the 70s. Rain chances? Well, they don’t look especially high this weekend, so if you are one of the few to catch a cooling downpour, consider yourself lucky.

Labor Day

Between a weak front trying nudge in from the north (sorry, not our first autumn cold front) and increasing amounts of moisture off the Gulf, we should see rain chances perk up some on Monday. It will start off like the rest of the weekend, but watch for building rain chances in the afternoon. High temperatures will be in at least the mid-90s on Monday, possibly a tick or two hotter. Morning lows will be in the 70s once more.

Next week/Invest 91L

Beyond Monday, forecast confidence drops off some. We have a combination of factors contributing to this. For one, that weak front in interior Texas will still be there. Second, that area we’ve been discussing for the tropics in the southwest Caribbean is expected to move into the Gulf next week. Models continue to wax and wane on development potential with this one (dubbed Invest 91L). Last night’s models were a bit more aggressive, with both the GFS & Euro showing a likely tropical storm. But the timing is all over the place, as is the track, so we honestly can’t read much into specifics right now. But with all that moisture just sitting offshore, it does present some modest forecast challenges.

So what is the best thinking on this right now? The signals we’ve gotten from ensemble guidance and our modeling is that development of 91L, if any, should be a bit sluggish, especially early next week. The system will be bringing a healthy amount of moisture north as it drifts this way, and although most modeling shows that offshore or staying to our east, it’s much too close to write off this far in advance. We could see a couple days of more scattered storms, then a drying trend. Or we could see several days of scattered heavier storms, similar to what has occurred during a couple periods this summer. Or, yes, we could see a tropical storm type impact. Really, we don’t yet know. Our intent was to take the weekend off, but given this thing lurking, look for a post on either Sunday or Monday morning with the latest.

Regardless of what happens here, expect temperatures to step back a notch, so more like low to mid-90s, but we should continue to see warm morning and overnights. There are no signs of a meaningful autumn cold front for at least the next 10 days. But it is still a bit early.

Tropics

The main area for us to watch will remain Invest 91L, as discussed above. Outside of that, Hurricane Larry has 90 mph winds this morning out in the open Atlantic. Interests in Bermuda and perhaps Atlantic Canada should keep an eye on Larry.

The disturbance immediately behind Larry is struggling, so for us, there are no other concerns at this time. Again, look for an update from us on Sunday or Monday. Otherwise, have a safe Labor Day weekend!