Matt Lanza

Good morning. Let’s cover the next couple days, and then jump into the latest on the tropical system.

Today

It will be very hot once again today, with mid- to upper-90s likely across the region. Look for borderline heat advisory criteria once again, so be sure to take it easy if you must be outdoors. A stray downpour or slow moving storm is possible.

Thursday

Look for a more typical summertime afternoon tomorrow. We will likely hit the mid-90s before more numerous scattered storms pop up across the region. Some could produce heavy rainfall, though some parts of the area won’t see anything. Things should quiet down after sunset.

Friday, weekend, and future Barry

Let’s discuss the future of the Gulf disturbance, currently known as “Invest 92L,” or what should become Tropical Storm Barry tomorrow or Friday.

The one two sentence summary: Weather model data has shifted back a bit to the west with Barry, though the vast majority of output still keeps the center and worst impacts focused in Louisiana Friday through Sunday. Still, this would be close enough for at least some fringe impacts in Houston, and given that there is still some uncertainty, we cannot write off a further drift to the west, so be sure to check back in with us later today.

Now: The disturbance known as Invest 92L is over the Gulf, just south of Apalachicola, FL, or somewhere near the area I’ve circled in the satellite image below.

Over the course of today, 92L will likely slowly organize itself and drift to the south. Where exactly this occurs will have implications on both future track and intensity, so today is a critical day to watch observations and changes in modeling. It is possible, if not likely, that the National Hurricane Center will begin issuing advisories on this today or tonight, tagging it as a “potential tropical cyclone.”

Track: As of this morning, model data has shifted the track of 92L, as it develops into Tropical Storm Barry further west. Yesterday, model consensus pointed toward a track west and then a quicker lurch north into the Vermilion Bay area in Louisiana. This morning, that consensus has shifted about 50 to 75 miles further west toward Cameron, Louisiana. Here is a map of all the European ensemble tracks from the 51 ensemble members. What does this tell us? It’s basically the European model run 51 times with different initial conditions. This offers you a broader range of possibilities and includes some fringe ones you might not consider if you just use operational modeling.

What we look for is trend and consensus. Yesterday, consensus was to the east of where it is today, so the trend is drifting back closer to us, meaning we need to remain aware of what this storm does. And there are still a handful of ensemble members that want to bring this even farther to the west and south. This is a very uncertain outlook at this time. Ultimately, the forecast track of future Barry is too close for comfort. Although we will hopefully gain more clarity on that later today, it will be important to make sure you have your plan and kit in place in case you need to act quickly beginning tomorrow. Hopefully this stays to our east and that’s that, but we cannot promise that and uncertainty remains annoyingly high, given recent trends.

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Good evening. It’s just a wee bit hot out there this evening, so we hope folks are taking it easy. In this update, we will discuss the latest on the developing tropical system in the Gulf (Invest 92L or “Future Barry”) and what the latest model guidance has suggested.

One sentence summary: Our disturbance is finally heading into the Gulf and will spend the next 24 hours or so slowly figuring out where exactly it wants the center to form before heading west, which means there is still a good deal of uncertainty regarding the final outcome of this system.

Now

Invest 92L is somewhere over the Florida Panhandle or just offshore; there isn’t quite a defined center just yet. This is half the challenge with the forecast. We are relying on models to tell us where the center will form, not basing the forecast off an actual center. So there is some inherent uncertainty in the forecast because of this.

With that in mind, there are clearly plenty of storms along the eastern Gulf Coast, and these will slowly meander offshore tonight, allowing for 92L to figure out where it wants its center to form and how that relates to what is happening above it in the atmosphere. We should see a small uptick in track forecast confidence tomorrow morning, followed by perhaps a stronger uptick in confidence tomorrow afternoon.

Today’s modeling

In a nutshell, the Euro held firm, while the GFS trended toward the Euro. Both deterministic models indicate a storm tracking toward and arriving somewhere between Jefferson County, TX and Vermilion Bay, LA. Should that actually happen, impacts in the Houston area will be minimal, but Louisiana would take quite a hit from rainfall and some wind at the coast.

But, as I have to hammer home: Deterministic models are never the right tool to use when making a 4 to 5 day forecast, particularly for tropical storms. You need to look at ensembles. As I did yesterday evening, here is a look at the European ensemble’s track density forecast from the University of Albany.

This takes the forecast tracks of the 51 ensemble members of the Euro and gives you a “spray” chart to see where clustering for higher confidence may occur, and we clearly see that something like 60 to 70 percent of the ensembles bring this toward Louisiana. But there is still a persistent, call it 20 to 25 percent minority of these ensembles that insist this will come to Texas. Until the center forms, and I can see what modeling is saying at that point, I want to be cautious about being too optimistic that we are going to miss out on impacts from future Barry.

Why the faster turn north on the models today? Some of it may have to do with how 92L’s organization has gone so far, but some of it also likely has to do with the fact that over the last two to three model cycles, this trough over the Great Lakes and Midwest has trended a little stronger.

The stronger that trough is, the more ability it will have to “tug” 92L or Barry to the north. It may not necessarily capture it, but it could allow it to gain enough latitude fast enough to avoid a date with Texas or even western Louisiana. So that has been helpful for us. But again, until we know where that center is going to establish, we have to treat all individual model runs cautiously.

One final note: Weather modeling did shift a bit stronger with this system as it made landfall, which could indicate that while the ceiling on intensity for this storm may not be at an elite level, it could come ashore as a strengthening tropical storm or even low-end hurricane. So let’s hope that today’s track trends are accurate for us here in Houston.

So the bottom line this evening:

• Invest 92L is gradually emerging in the northeast Gulf as expected. Over the next 24 hours or so, it will gradually develop a center of circulation that we can lock in on to allow us to gain forecast confidence on track.
• Weather modeling held on to a shift to the east today, focusing the center and most impacts in Louisiana. 
• However, a notable minority of reliable data continues to cling to a potential further west scenario, closer to Houston. It’s because of this that we will be keeping our guard up until we get a sense of where the physical center of the storm is going to develop.
• Modeling also trended a bit stronger with the storm, keeping the idea in play of a strong tropical storm or even low-end hurricane at landfall, regardless of where it goes; another reason to not yet call an all-clear.

We will have another update for you in the morning. Meanwhile, stay tuned in and vigilant and take one final opportunity to make sure your hurricane kits and plans are up to date, just to be safe.

I will jump into the latest on the potential for a tropical depression or storm named Barry in just a moment. I did go extremely in depth on where we stood last evening with regard to Barry, which you can check out as well. First, we do still have some important weather (heat) to get through before that.

Today & Wednesday

Heat and humidity will dominate today once more. We should shoot for the mid- to upper-90s again this afternoon. Look for potential heat advisories again this afternoon.

Exercise heat precautions today, stay hydrated, and try to stay in air conditioning if possible in the late afternoon. After some noisy, soaking storms in northern parts of the metro area yesterday evening, we could again see a handful of showers again today, though coverage and intensity should be a bit reduced.

Wednesday looks even worse with high heat and humidity. Expect upper-90s and risk for heat advisories again. There could be one or two showers around but nothing more.

Thursday

We should begin to feel some influence from the potential tropical depression or storm in the Gulf by Thursday, which would just mean a few scattered showers or storms at this point on Thursday afternoon. Otherwise, it will be hot and humid with solid mid-90s if not a little hotter.

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You had questions, we’ve got (some) answers. With the potential of a tropical system (also referred to as Invest 92L or “future Barry”) in the Gulf later this week, I thought I would do a reader-driven Q&A. I looked at comments from our morning post and asked on Twitter what questions folks had, and I’ve chosen some to answer here. I can’t get to a lot of questions in the comments, especially on Facebook, unfortunately simply because of time. So I apologize for that, but hopefully most of what people are wondering will be answered in our at least twice daily posts going forward.

I am traveling from X to Y and I want to know what weather I will encounter. Can you help?

I need to answer this one right out of the gate because based on the volume of questions I’ve seen, it would seem all of Texas is on a beach between New Orleans and Panama City this week. Here is what I can tell you: Given the current forecast, it’s going to be a bit of a stormy period along most of the Gulf Coast between Lafayette, LA and the Panhandle. So expect showers and storms each day scattered about with heavy rain possible in spots, especially Thursday and Friday. I do think travel across Louisiana is going to be challenging later Friday and Saturday before whatever this thing is moves ashore and begins to pull away.

Houston would likely be free of any serious issues through at least Friday. So if you have travel plans between Houston and points east, it will get progressively worse Thursday into Friday, peak on Saturday or early Sunday, and gradually improve beyond that. That’s the best we can tell you right now.

Do I need to panic? Is this another Harvey? How much rain?

I mentioned this in our morning post, but it needs a bit more prominence here: No, this is not another Harvey. No, you don’t need to panic. You do need to stay aware, however. That storm was unique, and it would take a truly special set of circumstances to see that again. That being said: We always tell you that no two flood events are alike. Whenever there is a risk of heavy rain, there is a risk of flooding in Houston. It will be its own unique event, and given the current rainfall forecast of 5 to 15 inches in the wide region between southeast Texas and southwest Louisiana, yes flooding is a distinct possibility.

Thankfully, this storm should be moving steadily, so we do not believe it will linger down here for 5 days, though storm chances will remain in the forecast into next week. This rain forecast will be fine-tuned in the next few days, so expect some changes, but prepare as if we will be dealing with a heavy rain event in the area this weekend.

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