Gulf Depression moving towards Texas

Remember the typical August weather that we HAVE NOT seen this year? Highs that stopped about 90-92 with those almost daily scattered storms? This week is your chance to experience that with deep blue skies, clouds that look like mountains, and that occasional shower or storm. All courtesy of what I expect to be a tropical depression, maybe eventually a tropical storm, that is forming about 120 miles south of the mouth of the Mississippi River.

Though I wish I could show you animation, you can easily see the swirl in this visible image from about 3:30 PM. Though there’s plenty of holes in between the clouds, you can see some storms building near the center which looks like an early location for an eye. This formed quickly on a leftover front— that “front” that gave us the storms on Thursday. For a change, there’s little wind shear in the Northern Gulf and there’s adequate mid-level moisture, so this should develop.

The good news is that this will head to Texas. An upper level ridge is to our north (the green H in the map below) protecting us, so this forming storm won’t make a bee-line for us in SE Louisiana. Instead, it will ride around the south end of the ridge (heat dome) moving in a due west direction. By Tuesday, the ridge will move east allowing the storm to move NW into the Upper Texas Coast between Houston and Beaumont Tuesday evening to early Wednesday. The biggest impact there should be heavy rain, but this will be a small storm so it’s possible there could be some locally heavy wind in one of the Texas counties.

For us, when the storm gets west of us tomorrow, we’ll be in deep tropical moisture off the Gulf and could see storms begin in the morning hours near the Lake and Sound, developing inland as the day progresses. The same scene could take place Tuesday, but with the center moving away from us and the small nature of the system, we won’t see flash flooding. The system will stay small because the overall pattern does not favor upward motion on a large geographic scale (Wrong phase of Madden-Julian if that means anything to you). For the week as whole, expect higher rain totals on the Southshore and near the Lake and Sound rather than 30 miles inland.

I’ll cover what’s going on with the remains of TS Dolly in the long range section below.

The Foreca graphic looks like its meant for a cardiologist. Translation: Very little day-to-day change in a regular pattern. Highs in the 88-92 range will be a welcome relief from the mid-upper 90s of a week ago. I see less rainfall and cloud cover on Wednesday when the depression moves slowly inland in Texas. Then, showers and storms will be more likely Thursday through Saturday. . Weekly rainfall totals could be an inch or two, again with the higher amounts on the Southshore.

Though Dolly has died, she has not disappeared. Don’t read too much into that statement. A strong thunderstorm system is visible just south of Puerto Rico, but it looks more like a Midwest severe thunderstorm outbreak with it’s V shape than anything circular. That’s a tell-tale sign of wind shear. The thunderstorms from the westward-moving, low-level wave are getting their tops blown off to the northeast. That, plus the fact that the system’s circulation must cross the mountains of the Dominican Republic do not give us any reason to believe that Dolly will reform in the next three days.

However, a small percentage of the model runs redevelop something near Florida over the coming weekend from the remains of Dolly. If this were to happen, and it was anywhere close to South or Central Florida (either West or East Coast), upper air conditions would favor it taking an abrupt right hand turn and heading out to the Atlantic. This graphic shows why: It’s a European upper air forecast for next Sunday morning depicting an upper level trough (yellows and orange) with winds shown in blue. Somehow Dolly would have to slip under that system for it to make it into the Central Gulf — at this point, something that seems unlikely.

Why all of this when I thought we might escape the season without even a discussion of a possible threat? Dominant patterns in meteorology rarely last the entire season. This is a week where the wind shear has retreated a bit to the south. I don’t expect this trend to continue.

Now through Thursday looks wet with 60% chance of storms or more. Shower chances drop to 30-40% after that. Rip currents will be a problem for a few days. Temperatures in the 80s with a mix of clouds and sun. Not great beach weather.