Two tropical waves to bring a surge of moisture into Texas

Good morning! After its first 19 days, this month was on pace to become Houston’s warmest July ever on record, besting 1980 by nearly 1 full degree. However, with cooler weather ahead this week due to clouds and rainfall, we should back off those temperatures somewhat. Indeed, the story for the next week will be rainfall and tropical moisture, with two tropical waves headed this way.

Monday

The first of two tropical waves lies just off the Texas coast, and will push inland today and Tuesday. (Note: The National Hurricane Center has given this system a 10 percent chance of forming into a tropical depression). As this moisture moves inland, we’re likely to see a greater than 50 percent chance of rain for coastal counties, and a less than 50 percent chance of rain for inland counties. Overall accumulations should be on the lower side Monday, with most areas likely seeing one-half inch of rain, or less. Clouds will help limit temperatures in the low 90s, with overnight lows in the upper 70s.

Tuesday

By Tuesday, as the bulk of the tropical wave moves onshore, much of the area should see a healthy chance of rain showers, well above 50 percent. Accumulations for most people should be about one-half inch of rain, but due to the tropical nature of this moisture, we probably will see some bullseyes that produce up a few inches of rainfall fairly quickly. With cloudy skies and showers, high temperatures should be limited to about 90 degrees.

Wednesday and Thursday

Some rain chances will linger for both of these days, but we expect showers to be of a more scattered nature. With drier air, we can expect to see some sunshine on both of these days, and this will allow high temperatures to climb into the low- to mid-90s.

Friday and Saturday

A second tropical wave will approach Texas on Thursday night, and this one has a slightly better chance of organizing into a tropical depression or storm as it moves across the Gulf of Mexico. The National Hurricane Center predicts there is about a 20 percent chance of this system become a tropical depression or storm by Saturday morning. There is some support for this in the ensemble models, and it would not surprise me to see this become a depression. However, for now there remains little (no) evidence for anything stronger than a weak tropical storm, so the primary threat from this system is likely rainfall.

For coastal Texas, this probably means an increase in rain chances to about 70 percent for both days. But so far accumulations look manageable—perhaps a few inches of rainfall along the coast as the system should move steadily to the west or northwest. Needless to say we’re monitoring this closely, but right now we see no cause for alarm. Highs both days will likely top out at about 90 degrees.

Sunday and beyond

After the second tropical wave, we anticipate rain chances settling down some, with a warming trend likely heading into the beginning of August.