Matt Lanza

After a summer of fishing for things to talk about in each week’s Eye on the Tropics, we’re quickly transitioning into peak season now, with a number of things to discuss. Today’s post will explain one system that should bring us some boosted rain chances heading into the weekend or next week, the chance of activity in the Atlantic, and what the pattern change expected over Texas will mean for us in terms of tropical risks.

Tropical outlook in a sentence

Activity should begin to ramp up this weekend and next week with a possible weak system in the Bay of Campeche, followed up by some additional tropical waves in the pipeline across the Atlantic worth watching.

Bay of Campeche & south Texas

This weekend saw tremendously beneficial rains in far south Texas. There may be more coming but who sees them remains a question. A tropical wave located over the southwest Caribbean is expected to move generally northwest over the next few days.

The National Hurricane Center is giving this about a 20% chance of developing into a depression or storm over the next 2 to 5 days. While a lot of folks will see this and be alarmed, there are reasons to think this system will struggle in terms of organization. For one, while wind shear was low in the Gulf as Invest 98L came crashing ashore on Sunday, wind shear in the western Caribbean and Bay of Campeche is not low. It’s fairly robust, and based on most model data I’ve looked at, some elements of shear are going to persist around this system until it comes ashore. My hope is that this will cap the ceiling on intensity potential.

The other reason not to really worry is that the pattern is going to likely keep it from coming up the Texas coast. It will track toward northern Mexico or the Rio Grande Valley as a disorganized tropical low, depression, or low-end storm. No credible modeling shows anything worse than that right now.

While South Texas saw a heck of a lot of rain from Invest 98L, where the rain falls this time around will be a little trickier to project. If the system can organize some, heavier rain is possible again in South Texas, while scattered storms would impact the Houston area at times. If the system remains rather disorganized, it’s possible that South Texas will see limited rain, but the bulk of the moisture coming from this wave will end up entrained in a cold front stalled over north Texas, bringing heavier rain to the Panhandle, DFW area, and into northern Louisiana and Arkansas. In that case, again Houston would see just scattered storms.

So for now, while I wouldn’t worry about this one specifically, I would continue monitoring it to see how rain chances will evolve.

Atlantic waves

Behind this wave, there are a few others in the deeper Atlantic.

Modeling is showing a lot more noise in the Atlantic from these waves now, meaning more ensemble model members are developing some of them. However, there’s not a whole lot of signal in the noise. That’s both good news and bad news. It’s bad because it doesn’t give us anything to hone in on just yet. So, all we can say is “Hey, the tropics are going to be active in late August.” Bold statement! But it’s good because there’s always a chance that the lack of signal indicates the environment will remain somewhat hostile toward tropical development. We’ll continue watching this to see if there’s anything to latch onto in the coming days, but as of now there’s nothing to hang our hats on.

Does the pattern change mean a change in Texas’s tropics risk?

We’ll close today’s note with a quick comment about the big picture pattern. For most of summer, Texas has been shielded by high pressure over the southern Plains and Central United States. This is why June and July were so hot.

That high pressure system acted to basically keep us hot, dry, and protected from any Gulf threats all season. The pattern is changing now, rather dramatically. The new look will feature high pressure mostly anchored in the northern Rockies or western Canada, as well as near Bermuda, with a rather healthy trough in the Eastern United States.

This means a couple things. For one, we’re no longer really “shielded” from the Gulf. So anything that can get into the Gulf will be apt to gain a bit more latitude than it would have back in June, July, or early August. That certainly doesn’t guarantee that we’re at risk for storms, but it has made us more vulnerable. That said, the other element to this is that the trough in the East *may* act to help “pick up” Atlantic systems more easily. In other words, the stuff coming off Africa may be more likely to get lifted north earlier, which favors either out to sea tracks or up the East Coast tracks. So our focus would probably be less on long-tracking storms from Africa and remain on systems like 98L, this week’s system coming out of the Caribbean, or anything that can spin up on the tail end of old fronts. So, this is a good news/bad news sort of scenario for us. The key points I want you take away from this post today are:

• The tropics are finally coming alive, as is usually the case in late August.
• The main system to watch right now, a tropical wave in the Caribbean, will likely track toward far south Texas or Mexico this weekend and increase our rain chances some.
• Additional waves have the potential to develop farther out in the Atlantic next week, but none looks like a slam dunk just yet.
• The general pattern change we will see in Texas is going to leave us open to local, “homebrew” Gulf threats, but there is a chance that the pattern in the Eastern U.S. will favor deep Atlantic systems turning out to sea or perhaps getting closer to the East Coast.
• With the season ramping up now, it’s time to start checking in once each day or two to see what’s happening and make your final checks on emergency kits and plans while we grind through things into September.

This may or may not be our last weekly post on the tropics, as we may have enough to discuss daily now. Regardless, stay with us for updates on anything of note in the days ahead.

Invest 98L, the tropical disturbance we’ve been watching over the Gulf the last couple days, is now ashore in South Texas, ending any potential development concerns. And it’s probably a good thing, as the disturbance finally starting organizing more rapidly overnight and this morning.

Another 12 to 24 hours over water probably would have led to a formidable named storm. Thankfully, that isn’t the case, and the steady march westward of 98L will continue through the day. For our neighbors to the south, this is about as good an outcome as you could ever ask for: Widespread drought-easing tropical rains without the damaging impacts of a strong tropical storm or hurricane.

Additional rains will add up to about 1 to 4 inches, maybe a bit more in some spots in far south Texas or northern Mexico. Flash flooding is definitely a possibility in spots, but in most cases, it should be brief and manageable. More importantly, reservoirs and rivers in that region will get a boost.

Houston weather

For the Houston area, 98L’s last minute organization really robbed us of moisture to work with initially. As winds turn back onshore today, we should see a slight bump up in shower activity leading to more scattered action. The highest odds of rain will be near Matagorda Bay, with the lowest odds northeast of Houston. Still, there will be scattered showers around anywhere today, and even if your neighborhood will probably remain dry, it will be good to take an umbrella with you if you’ll be out and about. Highs into the mid-90s, cooler south, hotter inland.

Rain chances drop off substantially Monday, Tuesday, and Wednesday. Look for a return to upper-90s, if not 100 degrees in much of our area to start the upcoming week. Better rain chances are still on target to return Thursday or Friday, as a generally wetter, cooler pattern tries to establish over Texas. I don’t want to overstate anything, but modeling continues to strongly argue for a bonafide pattern change in Texas heading into and beyond next weekend. Eric will have more for you tomorrow morning.

Friday saw some very scattered rain across the area. Most inland areas got nothing, but a few spots picked up a half-inch to an inch or so. A few areas around Galveston Bay and along the coast saw a bit more. That refrain will be with us today, with inland areas mostly escaping storms, but coastal areas seeing the highest odds. This is thanks to Invest 98L, the tropical disturbance off the coast that will be tracking toward the southern part of Texas, keeping most of the rain to our south.

Invest 98L

A look at satellite this morning shows that 98L is spinning away in the Gulf. It remains ill-defined, so any development is not going to happen quickly, and it will almost certainly run out of time to become anything of note before coming ashore.

A reconnaissance aircraft is on the schedule to investigate this system around midday today, if it is still deemed necessary. The three big points from our perspective are:

1.) Any tropical development is going to be low-end and short-lived.

2.) No direct impacts are expected in the Houston area or along the coast north of Freeport.

3.) The primary issue in South Texas (Rio Grande Valley, Brush Country, Corpus Christi) from 98L will be heavy rainfall, mostly beneficial but perhaps enough to produce some flash flooding.

Minor coastal impacts, like some erosion or wave runup are possible from Matagorda Bay south. For Galveston down through Surfside Beach, the water may runup the beach a good bit at high tide but flooding is not expected.

Houston area

With 98L not a direct concern for us, we will be on shower watch today. From downtown Houston to the north and west, minimal shower activity is expected today, with just a handful of downpours possible, much like yesterday. South and east of downtown, the odds of showers are notably higher, but even there it will be mostly just scattered in nature, meaning some folks won’t see rain. Wherever showers do fall, a quick half-inch to inch will be possible. Highs will range from the 80s on the coast to upper-90s inland.

For Sunday, expect much more of the same. Some of Sunday will depend on how organized 98L gets before coming ashore. If it can consolidate most storminess, it may keep most areas, even near the coast dry. If it remains broadly disorganized, scattered showers will be more likely, mainly south and east of downtown Houston. We’ll update you on this tomorrow!

We apologize if you did not receive an email yesterday. We had some technical issues to sort out, and hopefully those are fixed before I press send today!

While we lacked any organized storms on Thursday, there were some neighborhoods that saw a smattering of rain. Other places saw rain or heard thunder in the middle of the night. Rain chances will stick with us through Sunday, but the focus is going to lean more to our south or along the coast.

Today & weekend

Radar this morning is buzzing from Houston to points southeast. Scattered downpours are with us.

As the day progresses, the focus will continue to likely back down to areas closer to the coast. Inland areas will still carry a chance for rain as well, but most modeling (and the morning radar imagery) suggests the bulk of today’s showers will remain south and east of Houston. Low rain chances doesn’t mean no rain chances, and any rain that does fall could be heavy and add up to an inch or so over a short amount of time.

Highs will be variable today, ranging from the 80s near the coast to the low or mid 90s inland and perhaps near 100 in the Brazos Valley.

One wild card in the forecast the next few days is what’s happening in the Gulf. Recall from Tuesday’s Eye on the Tropics post, we noted that the Gulf would be the area to at least monitor.

Well, as of Friday morning, there is a disturbance in the Gulf, and while it’s not currently expected to develop, what it may do is focus shower and storm activity offshore at times this weekend. The system itself will track toward Corpus Christi or Brownsville, pushing inland on Sunday. Assuming showers and storms do focus closer to that system, that could mean that we see relatively low rain chances in the Houston area for Saturday.

So, for both weekend days, expect to see sun, clouds, and at least a few showers and storms in the area. The greatest coverage and highest chances will be along the coast, with chances dropping off significantly as you head north or west from Highway 59. All of us have some chance at rain this weekend, but your odds increase south and east of Houston. Sunday could see higher rainfall coverage a little more inland as winds become less parallel to the coast and more onshore. But we’ll assess that through the weekend and keep you posted.

Total forecast rainfall this weekend (ending Monday morning) is shown below. While some areas will see more rain than this and others less, this map is a good average of where we think things will end up over the coming days.

Temperatures will be quite variable this weekend, perhaps only in the low 80s with clouds and showers on the coast, mid-90s in Houston proper, and upper 90s to near 100 well inland.

Early next week

We revert back to the usual Summer 2022 fare Monday through Wednesday of next week. We will likely see mid to upper-90s in Houston, with 100+ farther inland and lower 90s at the coast.

Rain chances should drop to about 10, maybe 20 percent each day.

Later next week

I’ve been watching the weather model forecasts all week with some curiosity for late next week or weekend. There have been hints of a cooler, wetter pattern arriving across all of Texas on both the GFS & European models. While it’s too soon to get into details, it does appear we will see a chance at a front in the area, some “less hot” (not cool) weather, and potentially some higher rain chances than normal by next weekend. We have been burned by these scenarios more than once this summer, so I’m not exactly jumping in with both feet here. But there’s a healthy amount of evidence that rain chances will pick up further in 8 to 10 days. More on this Monday.

We’ll keep you posted on the rain chances this weekend with a post or two tomorrow or Sunday.