Odds increasing for a tropical storm to form in the Gulf, but it’s really not something to stress about

In brief: The National Hurricane Center has raised the odds of a tropical depression or storm forming in the Southern Gulf during the next day or two. This post seeks to quell any fears this may cause Texas residents. In the greater Houston area we can expect elevated rain chances on Friday and Saturday, but nothing extreme.

Satellite image of Invest 98L as of 3:01 pm CT. (NOAA)

Invest 98L status

Early this afternoon the National Hurricane Center increased the likelihood that a tropical system in the extreme southern Gulf, Invest 98L, will form into a tropical depression or storm during the next two days. The odds this morning were 20 percent, and as of 1 pm CT they are now 40 percent. Accordingly the color of the “tropical blob” on the hurricane center’s site has gone from yellow to orange. This has prompted a number of questions from readers about this system, and a measure of concern.

Hello, orange blob. (National Hurricane Center)

Our most important message is that residents of the greater Houston metro area really should not be concerned.

We will get a better idea about the nature of this system later today when a Hurricane Hunter aircraft flies into it to retrieve data about wind speeds, air pressure, and more. In any case, as of early afternoon on Thursday, the system does not have a closed circulation. However the satellite appearance is improving (in the sense that it is becoming better organized) and there are increasing amounts of thunderstorms. So it is moving in the right direction toward becoming a depression.

Select track forecasts for Invest 98L. (Weather Bell)

It is therefore plausible that this could become a tropical depression or a low-end tropical storm during the next 24 hours. However, by Friday afternoon or evening this should have moved inland, likely somewhere between Brownsville and Corpus Christi. Given this short window of opportunity, we think there is a pretty hard limit on how strong the storm can get.

The primary impacts from Invest 98L will therefore be rainfall. And although we can never be too sure about tropical systems, in August, moving into Texas, this one appears to be largely beneficial in terms of the precipitation it will produce. For the greater Houston region this means an elevated chance of showers, some of it potentially heavy, on Friday into Saturday. Coastal regions face the highest risk, with some areas perhaps seeing a bullseye of 1 to 3 inches of rain. Still, I expect most people will receive less than 1 inch, with the majority of that probably less than 0.5 inch.

More tomorrow.

Daily shower and thunderstorm chances continue as Houston passes ‘hottest’ period of the year

In brief: Summer is by no means over, but based on climatological temperatures we have now crested the peak heating for this year. And there’s no sign of extreme heat any time soon, with highs in the 90s for the foreseeable future and daily rain chances. As Cypress and Klein saw Wednesday, isolated thunderstorms are a possibility as well.

Past the peak

Don’t look now, but fall is on the horizon. We are still about one month away from having any real expectation of a decent cold front, but Houston has passed over the ‘hump’ of summer. The traditionally hottest time of year comes from late July through the first 12 days of August. This is when the average high is 96 degrees. As of today, the average high is 95 degrees. So we are taking baby steps.

I don’t want anyone to be fooled, of course. These are climatological averages, and individual years can bring significant variability. Often times the city of Houston sees some of its hottest daytime temperatures of the year in late August and early September. However, the average temperature is lower due to shortening days and the occasional weak front. All of this is to say that we are getting through summer, y’all. And the good news is that, for now, we don’t have any 100-degree weather in the forecast.

All things considered, this is not a bad high temperature forecast for mid-August. (Weather Bell)

Thursday

What we have in the forecast for today is a decent chance of showers, especially closer to the coast. By now you’re familiar with this pattern. Somewhere in the region this afternoon, or early evening, we’re likely to see a decent cluster of showers and thunderstorms. Most of the area won’t see any rain, or just some light sprinkles. But a few places—yesterday it was Cypress and Klein—might pick up 1 to 2 inches. This is likely to be the setup later today as well, and it’s precisely what I mean when I say we will have scattered showers and isolated downpours.

High temperatures will depend on the extent of shower coverage later this afternoon, but most of us should see highs in the low- to mid-90s, with plenty of humidity of course. Nights have been really warm of late, and I expect most of the city will not drop below 80 degrees tonight. Winds remain light, outside of thunderstorms in which there can be strong gusts.

Friday and Saturday

You may have noticed a ‘tropical blob’ highlighted in the Gulf by the National Hurricane Center. This remains unlikely to develop into a tropical depression or storm, and it has a limited window before moving into Mexico or southern Texas late on Friday. (If there’s a significant change to this outlook, we will update the site immediately. But we don’t expect this to happen).

Regardless of development, this system will inject a little more moisture into our area. This should raise rain chances to 50 or 60 percent on Friday and Saturday in the greater Houston area. Overall accumulations will still be on the order of one-half inch (or less) for most locations. But just know there could be some disruptive showers pulsing through. High temperatures for most of the region will top out in the lower to mid-90s on Friday and Saturday.

Sunday and beyond

By the second half of the weekend some high pressure is going to try and work its way into the area, but I don’t think our daily weather is going to change too much. We are likely to see high temperatures generally in the low- to mid-90s (a few far inland areas may push into the upper 90s) with a smattering of afternoon showers and thunderstorms. It should be fairly typical for mid-August in Houston, and as we’ve discussed before, any time we get ‘boring’ weather during this time of year we’re doing very well.

Tropical outlook for Thursday morning. (National Hurricane Center)

Atlantic tropics

I’ve already mentioned the Gulf tropical low above: It’s not a major concern for us, or probably anyone. Then there is Tropical Storm Erin, which is on its way to becoming the season’s first hurricane. It is likely to pass north of the Caribbean Sea. It will approach the southeastern United States next week but probably (although not yet certainly) curve before reaching the mainland. Bermuda faces a definite risk next week from Erin. Beyond this there are no imminent threats and the Gulf looks quiet for the next 10 days or so.

Typical August weather continues for Houston as Atlantic tropics continue to wake up

In brief: Parts of central Houston saw some fairly strong showers and thunderstorms on Tuesday, with a few isolated areas picking up 1 inch, or more, of rain. That pattern of sporadic afternoon storms should occur through Saturday before high pressure asserts a little more control. We also discuss the chances of a tropical system forming in the southern Gulf late this week.

Wednesday

The overall story remains the same for Houston’s weather in the coming days, with hot weather and just enough instability and moisture to support the possibility of scattered showers and isolated thunderstorms. These storms are most likely during the afternoon and evening hours, at a time when kids are coming home from school, participating in after-school activities, or during the evening commute. Today, however, I expect slightly less coverage than we saw on Tuesday. Overall I would say there is about a 30 percent chance of showers, with isolated storms. Highs today will range from the lower 90s near the coast to the upper 90s inland, with plenty of humidity.

Wet bulb globe temperatures remain in the “high” range this week, but that is typical for August here. (Weather Bell)

One thing that’s been noticeable this summer, to me, is the lighter winds. This is because we have not seen tight pressure gradients (i.e. very strong pressure systems) to really draw in the onshore winds. Today, for example, winds will come from the west at about 5 mph, with only slightly higher gusts. Winds may be a little more pronounced on Friday and Saturday, but overall they look to remain in the 5 to 10 mph range for quite a while.

Thursday and Friday

The forecast remains similar to end the work week, with highs in the 90s. Thursday and Friday may see slightly better rain chances, with 50 percent coverage of showers, and a few embedded thunderstorms. The most likely period for these showers remains the afternoon.

Saturday and Sunday

Saturday should see a continuation of this pattern, with highs in the mid-90s for most locations and a healthy chance of showers and thunderstorms. As high pressure starts to build some, I think most of Houston may push into the upper 90s on Sunday, with decreased (but non-zero, to be clear) rain chances. All in all this should be one of our hottest weekends of the year, which is to be expected in mid-August.

Next week

Temperatures for most of next week look hot, in the mid- to upper-90s, with lots of sunshine. I think rain chances will take a step back toward the 20 to 30 percent daily range. So yeah, full-on summer for Houston.

The Atlantic tropical outlook, now featuring a Southern Gulf of Mexico blob. (National Hurricane Center)

The tropics come alive

In the Atlantic Tropical Storm Erin continues to struggle with the intrusion of some drier air, but should soon move into more favorable conditions. A hurricane is likely to form later this week, or this weekend. The majority of modeling still shows the system turning before threatening the United States, but Bermuda is definitely at risk.

The European model ensembles indicate a low-end chance of something developing in the Bay of Campeche on Friday. (National Hurricane Center)

Additionally the National Hurricane Center is tracking a low pressure system that should emerge into the Bay of Campeche on Thursday or so. There is a slight chance of some development over the southern Gulf, and you always want to keep an eye on anything in that region in August. However, none of the models are particularly excited about this tropical low, and the atmospheric conditions are not super supportive. So, at this point, the most likely scenario is that the low has minimal to no impact on our weather. We’ll see.

August heat continues, and we finally answer our most asked questions

In brief: In today’s post we discuss our ongoing heat and decent rain chances, as well as a new tropical blob in the Gulf (which is not at all an issue for us). Also, we’re excited to share our first stab at a list of regional weather web sites, for other locations, that are similar in tenor to Space City Weather.

Regional weather sites (and other notes)

One of the most frequent questions we hear at Space City Weather goes something like this: “I’m moving to [insert destination] and I’m trying to find a weather blog there just like Space City Weather. Can you help?” Unfortunately, short of a handful of destinations we really could not.

So over the last few months our Dwight Silverman has been digging for independent, locally focused sources weather information. To qualify these sites also need to provide quality information (surprise, there’s a lot of junk out there) and be regularly updated. The end result of this is a page, which we will regularly update, that provides links to recommended regional weather sites. We welcome suggestions for sites to add, which you can provide at this Discourse comment thread.

While we are discussing site housekeeping notes, I also want to remind readers to make sure you’ve downloaded the latest version of our app. We think we have finally solved an issue that led to crashes on some iOS devices. Additionally, don’t forget that we’ve migrated our comment system over to Discourse. The goal is to make it easier for us to moderate conversations, highlight thoughtful contributions, and cut down on off-topic noise. 

Only the Panhandle is seeing slightly cooler weather this morning in Texas. (Weather Bell)

Tuesday

If your child is heading back to school today, rain showers have remained offshore for the most part this morning. So we’re left with a warm, and humid start to the school year—as is often the case during August. Skies will be mostly sunny this afternoon, allowing highs to reach the mid-90s for most of the region. Far inland areas may nudge up into the upper 90s, whereas coastal areas will top out in the lower 90s. Some scattered to isolated showers will be possible later this morning and into the afternoon hours, but I would put overall chances at only about 30 percent. We may see a few isolated downpours, but for the most part these should be light to moderate rains. Winds will be light. Lows tonight will only drop to around 80 degrees.

Speaking of tonight, the Perseid meteor shower peaks on Tuesday night, with the optimum time for viewing from 1 am to 5 am on Wednesday morning. We should be in luck with largely cloud-free skies, but a waning Moon will unfortunately provide some unwanted extra light. As always, viewing a meteor shower is best far from bright city lights.

Wednesday, Thursday, and Friday

The story remains largely the same for the rest of the week, with high temperatures generally in the mid-90s, mostly sunny skies, and spotty rain chances. Most of us probably will see at least some shower activity this week, especially closer to the coast. But for most of us accumulations will be at or below 0.5 inch. Nights (of course!) remain warm and muggy.

NOAA rain accumulation forecast for now through Sunday. (Weather Bell)

Saturday, Sunday, and beyond

As high pressure expands westward this weekend, we may see a few more high temperature readings in the upper 90s. But we should also still see some scattered daily shower chances, perhaps on the order of 30 percent daily. All in all, it should feel like a typical August weekend, which is to say hot, mostly sunny, and very humid. This pattern will likely continue into the start of next week.

Atlantic tropics

As expected, we are seeing the tropics come to life. Tropical Storm Erin formed on Monday, and this probably will become the season’s first hurricane within a couple of days. Erin is expected to track north of the Caribbean Sea. And while there is a non-zero threat that the storm moves toward the southeastern United States (probably less than 10 percent), at this point the biggest concern I have is in regard to Bermuda about one week from today. To be clear: there is no threat to the Gulf from Erin.

Atlantic tropics outlook as of Tuesday morning. (National Hurricane Center)

Speaking of the Gulf, there is a yellow X there this morning. However, as Matt pointed out on The Eyewall last night, there is a mountain of wind shear in the western Gulf right now, and the eastern Gulf isn’t exactly hospitable either. So this is just a run-of-the-mill surface trough interacting with warm water and hot, humid Gulf weather, producing lots of thunderstorms. It should slowly lift away from Texas toward the northern Gulf coast. So not at all a threat locally.