After Thursday’s kinda sorta front in Houston, we’re eyeing rain chances this weekend

Yesterday was a really interesting day across the broader version of southeast Texas. College Station maxed out at 73° on Thursday, which breaks the record of 77° from 1948 as the coolest maximum temperature recorded there on September 10th. Much of the western half of the Houston metro area saw dewpoints drop into the 60s with cooler temps much of Thursday morning. Hobby Airport never dropped below 79° until late Thursday evening. Galveston saw heat index values approach 110°. Many of us saw some rain, with a narrow strip from about the Texas Medical Center north and east past Mount Houston into Atascocita seeing multiple rounds of storms and anywhere from 1 to 4 inches of rain.

So overall, yesterday was a glorious day for some, a frustrating day for others, and something in between that for others still. We all kind of get back on the same page today and tomorrow.

Today

The cold front is essentially dead at this point. But! The air mass over us is notably drier, yes, and you will probably notice that the humidity today isn’t as oppressive as, say, Wednesday (or even yesterday for folks south and east of Houston that largely missed any tangible impact of the front on Thursday). But it will still feel like late summer in many spots. Those of you that experienced an autumn preview yesterday will probably see upper-80s to around 90° today. Most of the rest of the Houston area will see lower-90s. But again, with humidity down it may not feel super terrible.

In terms of rain chances, look for a few showers or storms this afternoon, especially south and due east of Houston with slowly diminishing chances as you go north and west.

Tropics & weekend

I wasn’t quite sure how to go about breaking up sections today, but given the complexity, I feel just hitting it all at once would be best. We’re watching two disturbances today, one in the Gulf and one over the Bahamas.

There are two tropical disturbances to watch, a weaker one in the eastern Gulf and a more robust one in the Bahamas (Weathernerds.org)

Clearly, one looks healthier than the other. The Bahamas one is now dubbed Invest 96L, and the National Hurricane Center is giving it a 60 percent chance of development over the next five days (40% over the next two days).

The NHC is giving the first Gulf disturbance a 30% chance of organizing over the next 5 days and the second disturbance a 60% chance over the next 5 days. (NOAA)

But we have to get through the lead disturbance first. This one has odds of 30 percent to develop over the next five days, but it seems that if it were to form, it likely wouldn’t happen until it gets south of our area toward Mexico. So why are we watching that lead disturbance? Well, it’s close enough to the coast that it will likely send a surge of moisture this way beginning tomorrow. This should be enough to generate numerous showers and storms offshore, along the coast and/or just inland on both Saturday and especially Sunday. If storms do blow up offshore significantly, it is possible that coastal areas may only see a little rain. Areas north and west of Houston may not see much rain at all this weekend.

Averaging together rain chances through Sunday gives the highest totals along the coast, with lesser amounts inland. (Weather Bell)

Total rainfall from Friday into this weekend will probably average under a quarter inch north and west of Houston and closer to a half-inch near the coast. Some areas will likely see higher amounts up over an inch, and others may see no rain at all. Flooding, other than the typical ponding or minor street flooding we see in heavy downpours is not expected this weekend.

After a morning low in the 70s Saturday, we’ll see humidity inch up all day, and with highs in the 90s, expect heat index values to surpass 100° once more. Back to late summer we go. On Sunday we’ll see similar temperatures or a little cooler weather due to more cloud cover. Humidity will remain high. Watch for some choppy conditions over the bays and in the Gulf with slightly increased winds (~15 mph) with onshore flow.

Tropics & next week

The second system will not impact us, if it does at all, until at least Wednesday or Thursday. So to start the week on Monday, look for scattered to numerous showers and storms, perhaps chances push a bit farther inland than the weekend. This pattern may continue Tuesday. By Wednesday, we could see a brief break before that second system gets involved Thursday.

Simple discussion: The next tropical wave is going to slowly work west across Florida and through the Gulf the next few days, possibly developing as it does so but likely coming ashore to our east. Regardless of any of that, it will increase our rain chances by Thursday or Friday.

More technical stuff: There’s a really high degree of uncertainty at the moment with respect to that Bahamas system. One the one hand, I looked at a bunch of weather models, even the speculative ones we constantly tell people not to bother looking at for tropical systems (I need a shower now), and I don’t see a single one developing it much past where it is now; maybe one or two get to depression level. But when you look at satellite above, it looks a lot better than I would have expected today. Additionally, it’s going to be over the Gulf for a time, and it will be in a low shear environment. Realistically, this has a better shot at development than any model gives it credit for right now. The only thing I can come up with to explain why the models don’t particularly care for it, is that a good chunk of its low-level vorticity or the most “spin” associated with the system ends up along the immediate Gulf Coast or, as the European model suggests, just inland. So the models likely sense this is too close to the coast to develop. Given how far south it appears to be right now, I think the Euro may be a bit off-kilter here, and although we’d still expect a general track toward southeast Louisiana, it’s worth continuing to watch.

What does it mean for us? Right now, we’ll just call for an increase in rain chances later next week and perhaps some choppy conditions offshore with some slightly gustier winds. At this time, we do not expect significant impacts to our area (or to Hurricane Laura damaged areas) beyond increasing rain chances and slightly higher tides. But again, given the disturbance’s location and the time of year, it would be foolish to write it off completely, so we’ll keep watching.

We will also watch for maybe, possibly a new chance to see cold front by next weekend. That’s literally all I’m going to say about that for now, and if it’s still there Monday, we’ll tell you about it.

Eye on the Tropics: The peak of hurricane season is here

Historically, this week marks the statistical peak of the Atlantic hurricane season. This year looks to live up to the hype as well.

The Atlantic looks like a basin that is at the peak of its season. (Weathernerds.org)

We have two tropical storms in the Atlantic today and there are likely to be at least a couple more before next week. We don’t think that any of these systems will seriously threaten the Gulf, however it is important to keep monitoring things, particularly with respect to the third system in line.

Tropical outlook in a sentence

Tropical Storms Paulette and Rene will likely be followed by a third system this week off Africa, and while none looks especially likely to make it to the Gulf, it would be wise not to write them off completely, particularly the third system, given the recent model difficulties we’ve seen.

Tropical Storm Rene

I want to get Rene out of the way first because I think this one has the least future of note, as it relates to the U.S.

Tropical Storm Rene is likely heading out to sea, though it is expected to become a hurricane as it does so. (NOAA)

Tropical Storm Rene has 40 mph maximum sustained winds, and it is impacting the Cabo Verde Islands today. It is expected to track west and then turn northwest and north as it finds a “weakness” in the upper air pattern. The pattern does get a bit convoluted late, so Rene seems to strike me as a storm that could hang around in the open Atlantic for awhile, possibly taking a weird track as it does so. But it will not be a threat to the U.S. or Caribbean.

Tropical Storm Paulette

Tropical Storm Paulette has winds of 50 mph, so it’s a bit stronger than Rene. It’s also farther west. Paulette’s future is a little more difficult to project.

Paulette is expected to track off to the west and eventually turn north. While it should go out to sea, there is a chance it could come a bit farther west. (NOAA)

Paulette is going to be steered back to the west a bit by a building area of high pressure in the upper atmosphere. The storm will then have an opportunity to escape off to the north by the weekend as another area of high pressure off the U.S. East Coast gets eroded by a system moving through New England. I think Paulette’s track is of slightly lower confidence by this time. My doubt rests in Paulette’s intensity. With this pattern, I do wonder if Paulette’s weak intensity this weekend will allow it to escape underneath all that nonsense off the East Coast, which would allow it end up farther south and west of the forecast. In that situation, Paulette’s turn out to sea might wait to commence until it gets between the U.S. and Bermuda, rather than east of Bermuda as currently shown. While it would still likely end up out to sea, it could potentially create a bit more heartburn for folks on the East Coast. We’re about a week away from Paulette getting west of Bermuda if that were to happen, so it’s a lot of speculation. For us in the Gulf, Paulette probably poses no meaningful risk, but I’d at least keep a slight eye on this if I lived on the East Coast.

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A smattering of showers, as we await clarity on next week’s possible cold front

We certainly have not been in a true “drought” this summer, but at times, we’ve flirted with some extended dry periods. We seem to be in one of those now. Over the last 60 days, we have seen mixed results in the rainfall department in our area.

Over the last 2 months, some parts of the Houston area have seen near normal rainfall, while others have seen about half of normal. (High Plains Regional Climate Center)

Parts of the Houston area, particularly down toward Hobby and Clear Lake have seen near average rainfall over the last two months. But, if you go up into western Montgomery County, some places have seen less the 50-percent of normal rainfall. Most of the Houston area is running drier than normal, and while parts of Texas have seen decent rainfall this week, most of Greater Houston has not. At least many of us will see a little rain in the next couple days, as we try to decipher the potential cold front riddle for next week.

Today

If you’re like me, perhaps you were woken up by thunder at 4:15 or so this morning. There have been a few storms focused mainly on the east and north sides of the city so far today. Places like Baytown, Pasadena, and Galena Park have seen around or above a half-inch of rain from those showers.

The rest of today will be characterized by scattered showers and storms. In trying to pinpoint any sort of rhyme or reason to how they’ll behave today, it would seem that they may try to focus in the Highway 59/I-69 corridor or just south this morning before slowly focusing more north and west as the day wears on.

Some of you won’t see any rain. Others could pick up an inch or two with some heavier downpours possible. Most of us will see slightly cooler weather today. Humidity will remain quite high, however, so don’t expect any sort of comfort in the Houston area. But, hey, at least Galveston finally dropped below 87 degrees this morning. Look for highs in the lower 90s and heat index values again jumping above 100 degrees, albeit somewhat less oppressive than earlier this week.

Weekend

Both weekend days will carry at least a chance of showers or a thunderstorm. As low pressure in the upper atmosphere gradually weakens and slips away, we’ll see a little less support for storms than perhaps we see today. Look for scattered showers both days, but with gradually less coverage. Many areas may not see much rain at all this weekend. Right now, places away from the coast look to have higher odds of rain, with a gradual shift south and west on Sunday.

Rainfall this weekend will total about a quarter to half-inch on average, with some seeing less and others seeing a bit more. (Weather Bell)

Total rainfall when all is said and done will likely average around  a quarter to half-inch of rain for most of the area. Again, some will see less, some a bit more. That’s just the nature of these types of setups. High temperatures will be in the low- to mid-90s this weekend, with our uncomfortably warm overnights continuing.

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Eye on the Tropics: So now what?

It’s kind of crazy to think that our last full tropical update was two weeks ago, and we noted how things were about to ramp up. For many folks in Louisiana, the world is a much different place today than it was then. For Houston, I think we had a moment there. You exhale, but then you realize that nothing has really changed, and all it takes is one more storm to bring us right back to where we were sitting in the days before Laura. So will that happen? Probably not, but let’s walk through things.

Tropical outlook in a sentence

We expect several systems to develop over the next week or two across the basin, but right now only one of them is worth seriously watching and even it will be racing against the potential cold front next week.

Potential Tropical Cyclone 16

The system that we referred to as Invest 99L yesterday has been classified as Potential Tropical Cyclone 16 (PTC 16) in the Caribbean this morning, meaning it is expected to become a depression or named entity soon. It looks fairly healthy on satellite, and it will likely develop over the next couple days.

Potential Tropical Cyclone 16 is not a threat to the Gulf of Mexico, but it will deliver heavy rain to parts of Central America. (NOAA)

Fortunately, thanks to our oppressive heat in Texas, with sprawling high pressure over the Gulf of Mexico, this will keep PTC 16 well to our south. No need to worry about this coming to the Gulf. So what is coming after this system?

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