Matt Lanza

Like we did in 2020, Eric and I are pleased to bring back the “Eye on the Tropics” series to Space City Weather. Each week, normally on Tuesday afternoons, either myself or Eric will write a more detailed post specific to tropical weather in the Atlantic. This allows us to go more in depth on what is happening, what we are watching, and what might be buzzing on social media with respect to tropical storms or hurricanes. We will keep these weekly updates going into August. Usually by mid-August there’s enough happening each day that we’re covering it in our daily posts.

Anyway, we are off to a roaring start this year.

Tropical outlook in a sentence

While we are monitoring the progress of a tropical wave east of the Caribbean islands and some model solutions have brought that or another system into the Gulf as a substantial tropical storm, there is still far too much uncertainty regarding its future to consider it a serious concern at this time.

2021 so far

Before we get to the Atlantic system we’re watching, let’s hit you with some statistics about the season so far. Claudette’s remnants are steaming out to sea in the Atlantic, our third named storm of the young 2021 hurricane season. While Claudette was quite quick to become our third storm, it did not come close to last year’s speed, when Cristobal was named on the 2nd of June. We won’t threaten the fastest to storm #4 either, as Danielle’s record in 2016 is already in the rearview mirror (June 20th). So, at least we aren’t quite pacing 2020 right now. Beyond that, there’s little to deduce based on this season’s activity so far.

Atlantic disturbance

The main thing to talk about this week is a disturbance in the Atlantic basin that the National Hurricane Center is currently giving 30 percent odds of development over the next couple days (Author’s note: Since publication, this has been dialed back to 20 percent odds).

This particular disturbance has probably already caused some folks heartburn as a few social media focused weather pages have irresponsibly shared operational model guidance from Sunday showing a presumed major hurricane hitting Texas in early July. What they don’t tell you, besides failing to offer any context, is that the very same model has subsequently sent a weaker storm to Brownsville, Mobile, the Florida Big Bend, Tampico, New Orleans, and Pensacola in various runs. In fact, I’ve put together a gif of the pinball game the GFS model has been playing lately below.

Again, some of the best advice we can give you, besides not looking at operational model runs to mentally prepare for a storm forecast, is to not waste your time on various Facebook weather pages that don’t identify who the authors are and with whom they are affiliated. But I digress.

So the real question is: Should we watch this system? The answer is yes but with the big caveat that there’s probably a very good chance this develops into nothing. And what some models have latched onto in the Gulf late next week may not even be directly associated with this system.

Looking at satellite imagery of the disturbance in question today, we can see just a disorganized “blob” of thunderstorms approaching the southern Windward Islands.

The NHC going with a low chance of development over the next 5 days seems reasonable based on this. The system is likely to be steered west or west-northwest around the periphery of high pressure in the Atlantic. This should bring it into the Caribbean, where conditions over the next 5 to 7 days won’t exactly be hospitable for development.

So even if this survives the trip, don’t expect it to be particularly healthy looking when it gets to the western Caribbean.

Beyond that, our ensemble guidance is very lukewarm on development and no real model at a place where I’m sitting up straighter in my chair out of concern. There’s some chance this could end up falling apart completely. It may make its way to the Pacific. Or perhaps it does indeed come to the Gulf. We don’t know, but we also don’t see anything notably alarming in model guidance either.

So the advice? Check back in every couple days for the latest, as you normally would during hurricane season. I would not waste energy worrying about this one though. Hurricane season is a marathon. Inevitably we are going to have to watch a storm or two with legitimate interest and concern come later July, August, or September. So pacing yourself if you can is a good plan of attack.

Anything else?

The good news is that beyond this system, there’s nothing else of note in the tropics. With a cold front crossing into our area this week and possibly another one next week, it’s probably best to not write the unexpected off completely. But there’s nothing in any modeling that suggests we need to really focus on anything specific for at least a little while.

Compared to earlier this week, it certainly feels a little more comfortable, with temperatures ranging from the mid or upper 60s well inland to around 80 degrees at the coast.

We will see another day or so of drier air, helping to keep us relatively comfortable, thanks in part to Potential Tropical Cyclone #3 in the Gulf, which will pass to our east into Louisiana. This farther east track leads to a handful of minor forecast changes this weekend.

Today & Saturday

Both today and tomorrow look fairly uneventful in our area, with a mix of sun and clouds. Yes, there could be a stray shower or two that makes into the Houston region, and there could be a portion of an outer band from PTC3 that grazes eastern fringes of our area. But aside from that, it will just be hot and a bit humid. Look for highs in the low to mid-90s (some isolated upper-90s can’t be ruled out) and lows in the 70s. Humidity will likely increase a bit tomorrow, and the morning will feel less comfortable than yesterday or today has felt.

The big weekend change is that rain chances look higher on Sunday than they do Saturday now.

Sunday

We begin a little more onshore flow on Sunday, which means more humidity. Morning lows in the upper-70s seem more likely here. It also means a better chance at isolated to scattered thunderstorms, as a weak disturbance in the upper atmosphere finds a route into Texas and taps into some of that onshore flow. Not everyone will see rain, but there will likely be at least a few showers or storms around Sunday afternoon. High temperatures will be in the mid-90s.

Monday

Right now, Monday looks like a classic June day in Houston with sun, clouds, high humidity, morning lows in the 70s, daytime highs in the low-90s, and a chance of afternoon thunderstorms.

Tuesday & beyond

By Monday night, an actual cold front will be moving across Texas from north to south. We are unlikely to enjoy the cooler, less humid benefits of said front, but we will likely see scattered to perhaps even numerous showers and thunderstorms on Tuesday. Locally heavy rain is possible here, and a healthy chunk of the area should see at least some rain. Expect a less hot day Tuesday, with some chance highs don’t get above 90 degrees.

By Wednesday and Thursday, rain chances won’t drop to zero, but they will diminish a bit as the front fizzles and high pressure begins to nose into the area. Look for highs back in the 90s and lows in the mid to upper-70s.

PTC 3 update

Potential Tropical Cyclone #3 continues across the Gulf this morning. To be honest, this is about as healthy as it has looked in its life cycle since it became an area to watch.

There’s a significant blowup of thunderstorms near and north/east of the center. This is why forecasters have been banging the drum regarding heavy rain being the main concern. Whatever the case, we assume we will see Tropical Storm Claudette come of this mess and approach the Louisiana coast tonight between Vermilion Bay and New Orleans.

Locally, no impacts are expected, aside from perhaps slightly rougher surf and stronger than normal rip currents. Please use caution if swimming in the Gulf this weekend.

The main impacts in Louisiana and the Southeast will be from heavy rainfall. About 4 to 8 inches of rain should fall in southeast Louisiana, southern Mississippi, southern Alabama, and portions of the Florida Panhandle.

Higher amounts will be possible there, but the system may actually move along fast enough now to prevent major problems. But if your travels take you east of Louisiana this weekend, plan accordingly.

We aren’t expecting significant forecast changes this weekend, so look for our next update, as per usual, on Monday morning.

Let’s be honest. It has felt like August lately. I mean, really. For Hobby Airport, the last 3 afternoons have tied for the 5th hottest 3-day stretch of high temperatures this early in the season (trailing several 3-day periods from 1998 and 2011, both notoriously hot Houston summers). For Houston officially it’s the 12th hottest 3-day stretch so early in the season. It’s hot, it’s early, and it’s not going to get much better this week.

Today

Look for temperatures surging into the 90s again today. We hit 98° at Bush and 99° at Hobby on Monday. Maybe we’ll do a degree or so cooler than that today.

Upper air temperatures are a little cooler today, and there should be better coverage of showers in the area. While we don’t expect everyone to see rain today, at least some places will, and there could be a few heavy downpours as well. Regardless, it’s going to be hot, so please take care outdoors. And it’s yet another ozone action day for those with respiratory ailments to take note of.

Also, apparently ERCOT needs our help again this week, so for the good of, like, everyone, please try to cut energy usage where you can.

Wednesday & Thursday

Both days should see sun, clouds, and very slight storm chances. Call it maybe 20 percent coverage. Maybe. The forecast is reminiscent of a 1990s Sears commercial. Another scorcher indeed. Look for solid mid to upper-90s on both days. There will be very little relief. Please make sure you’re taking it easy and checking in on anyone vulnerable in this kind of heat. We went from springtime to August-type weather in what felt like a matter of hours, so it’s tough for your body to adjust to this quickly.

Friday into the weekend

Besides the heat, which is the most pressing weather story today, we do continue to keep a close eye on the tropics. The National Hurricane Center has slowly but steadily been bumping up the odds that Invest 92L in the Bay of Campeche would develop into a tropical depression or storm this week. We sit at 70-percent odds as of 6 A.M. This morning, 92L remains a disorderly mess, so we continue to agree with the idea of very, very slow development.

The good news is that a couple things remain true forecast-wise with 92L today: It is not expected to significantly develop. It is expected to track near us or to our east. It is expected to be fairly lopsided, with most rain staying well east of Houston. On the unfortunate side, it likely means our somewhat excessive early-season heat will continue.

More specifically, expect 92L to gradually lift northward beginning Friday. Given the wind shear over the Gulf, dry air over Texas, and general disorganization of the system initially, development will be slow. Expect a possible center of circulation with something like 80 to 90 percent of the rainfall displaced to its east. Lopsided will be the appropriate word choice, I think. The system should head close to the Gulf Coast somewhere between about Galveston Bay through central Louisiana on Saturday. I would expect a depression or low-end tropical storm at this time and unlikely anything worse. The system is then expected to slide east across Louisiana and toward the Southeast and be out of our hair by the end of the weekend.

So how much rain are we expecting?

For the Houston area and points west, it’s likely to be sparse. Most folks should see maybe just a couple passing showers between now and Sunday. A few places will see slightly heavier showers, especially near the coast. But also, some places will see no rain at all. East of Houston and along the coast, the situation is a little trickier. Between here and Lake Charles, including Beaumont and Port Arthur, most places will probably see 1 to 2 inches of rain or less from passing showers and the rain shield from Invest 92L. Depending on the exact track and organization of 92L, this could change a bit in either direction. But in general, if there are going to be issues with flooding, they would likely be east of roughly Lafayette, LA.

Still, as always, we encourage you to check in once a day to see how this is progressing. And this is a good opportunity to build or refresh your hurricane kits and plans, which will help you all season long.

For those curious, elsewhere in the tropics, Tropical Storm Bill formed off the Carolina coast yesterday and is heading out to sea. The next name on the list is Claudette, which will make some folks around here cringe.

We will continue to watch, but at this point we believe heat to be the bigger story in Houston even into the weekend. Eric is back in the hot seat tomorrow and will have the latest then.

Houston summers are notably hot and humid. Many of us hate it, but it’s almost a badge of honor of sorts for us, right? Anyway, Hobby hit 100° yesterday and Bush hit 99° as well. For Hobby, that’s the third earliest date since 1930 that we’ve hit the century mark for the first time in a year, just being beat out by May 31, 1998 (100) and June 5, 2011 (102). At Bush Airport and officially for Houston, we tied for our eighth earliest first 99° reading. May 29, 1996 and June 2, 2011 top that list. The average for our first 99° at Bush is July 16th, and the average for our first 100° at Hobby is July 17th. This is very early for this kind of heat. Granted, we’re going to be dealing with a borderline historic ridge of high pressure in the West the next several days, so I guess it should not be much of a surprise, but after a very wet May, color me a bit surprised we went this far this fast. Hopefully not a harbinger of things to come this summer.

So the obvious question is: Will the heat last? Let’s try to answer that.

Today

While we expect today will be another scorcher of a day, we may end up a degree or so cooler than yesterday, and we may also see a couple more showers than we did yesterday too. Maybe. Most folks will still probably stay dry today though.

Upper air temperatures look stoutly warm this morning, but by evening they’re running a tick or two under Sunday. So, in general, expect mid to upper-90s today. Heat index values will get up over 105° in spots this afternoon, so please exercise caution if outside. In addition, today will be another ozone action day for the area, so take care if you have respiratory sensitivity.

Tuesday & Wednesday

Tomorrow we see a small bite taken out of the heat, so we’ll probably drop off another degree or two compared to Monday. We’ll call it mid-90s. Better rain chances look to arrive Tuesday, as a slightly larger scale disturbance in the upper atmosphere moves across the region. On Wednesday, we’ll see a good setup for at least scattered showers and storms. Look for mid-90s once more. Morning lows will be in the 70s to as warm as 80° perhaps.

If I were classifying rain chances, yesterday was about 5 to 10 percent coverage. Monday will be 10 to 20 percent, and Tuesday/Wednesday would be 30 percent coverage. So, many folks may not see any rain at all, but at least some of us should. Hopefully.

Thursday

On Thursday we stay flat or lose another degree or so in temperature, as we lie between high pressure dominating the West and a trough on the East Coast. Already low overall rain chances may lower a bit more on Thursday. Look for mid-90s by day and 70s to near 80° by night/morning.

Beyond Thursday (Tropics)

Looking out to Friday and beyond, our attention turns to Invest 92L, which I went in depth on yesterday. Honestly, not much has changed since that post. The system is still messy looking. It will still have high shear to deal with, and there will likely be some dry air over Texas that will attempt to fight it back a little bit. So there likely remains a fairly low ceiling on just how intense this system can become.

As Invest 92L comes north in a very sheared environment, it will likely continue to have the bulk of its moisture kicked off to our east. Again, if you look at a GFS model forecast of relative humidity in the upper atmosphere, generally a decent indicator of how constructive or destructive the environment will be surrounding a tropical system, there is a clear signal for very, very dry air over Texas. This likely means a.) a sharp cutoff to how far west precipitation can expand on the west side of the storm and b.) the risk that some of this dry air gets “entrained,” or wrapped into the system itself as it comes north, limiting how well-organized it can become.

So what does this mean for the Houston area from Friday into the weekend? While I’m certainly sounding very unexcited about rain from Invest 92L in the Houston area, it will boost our rainfall odds a bit from where they are on Thursday. So look for at least isolated to scattered showers or storms on Friday, Saturday, and Sunday as 92L draws north. Uncertainty increases a bit obviously as we march through this weekend, but in general, we continue to feel the heaviest rain will stay to our east, possibly well to our east. But I would expect at least some chance for scattered rain over the weekend. We’ll fine tune this through the week.

Temperatures, especially if rain stays well off to the east of Houston will likely be warm to quite hot heading into the weekend, maybe cooling a bit as rain chances increase.

With respect to your plans for the week or weekend and Invest 92L? I would not make any changes because of this system right now, but I would check back each day for an update to make sure nothing has significantly changed. More tomorrow.