Eric Berger

Update on Tropical Depression 19, and the busy tropics

Although the tropics pose no specific threats to Texas, in the interests of readers of this site all along the Gulf Coast Matt and I will provide updates today and Sunday on the threat posed by Tropical Depression 19.

The system is passing near the southern tip of the Florida peninsula this morning, and will move into the eastern Gulf of Mexico later today. Some time today it probably will become Tropical Storm Sally. One big question is how much wind shear the storm will have to grapple with over the coming days. If shear remains low, the storm will find ideal conditions to strengthen into a Category 1 or Category 2 hurricane over the warm Gulf. Otherwise, it will remain a tropical storm. Regardless, the primary threat is probably heavy rainfall, extending from Southeastern Louisiana along much of the western coast of Florida. For the northern Gulf Coast these heavy rains would likely come some time between Monday night and Wednesday morning.

NOAA rainfall accumulation forecast for now through Wednesday. (Pivotal Weather)

In terms of track, confidence is fairly high that the storm will make landfall somewhere between southeastern Louisiana and the Florida Panhandle—probably on Tuesday. The storm will move mostly westward or northwest until falling under the influence of a trough of low pressure over the continental United States that pulls it northward. Where precisely this happens will determine what part of the northern Gulf coast the storm strikes.

Forecast track map for TD 19 at 4am CT Saturday. (National Hurricane Center)

After this storm, over the open Atlantic Ocean, there are several other tropical waves that are candidates to develop into tropical storms or hurricanes. “Teddy” may therefore soon follow Sally. But at this time we see no specific threats to the Gulf of Mexico. In terms of the tropics, Texas seems to be in a pretty good place at this point.

The dying front will miss most of Houston, but bring slightly drier air

Good morning, Houston. As we watch the region’s first front approach our area, peter out, and die, I wanted to remind you one final time of Reliant’s sweepstakes to win a free AC System. We’ve already had one winner, but there’s still a second chance to win if you enter by next Tuesday. You can find an entry form, and details of the giveaway right here. It’s an entire, brand-new system—quite a deal.

Thursday

The aforementioned front has made it through College Station, and is pushing into areas such as Katy. It may make it all the way to northern parts of the I-45 corridor this morning, but it is quickly weakening. As the front stalls we should see showers develop over central and eastern parts of the area later this morning and during the afternoon. It will be the same drill as recent days, with hit-or-miss thunderstorms. High temperatures will vary widely today, from upper 70s far west of Houston to low 90s along the coast. As drier air filters in to the region, lows on Friday morning may be a few degrees cooler than normal for most of the metro region.

There will be a tremendous gradient in high temperatures on Thursday. (Pivotal Weather)

Friday and Saturday

Any semblance of the front will be gone by Friday, as summer returns in full force. Both of these days should see partly to mostly sunny skies with highs in the mid- to upper 90s. Rain chances will be lower, likely with only a few isolated to scattered showers developing during the afternoon.

Sunday through Wednesday

An upper level low pressure system will combine with a surge of tropical moisture during the first half of next week to bring better rain chances across the entire region, probably beginning later on Sunday. Right now we’re not looking at anything extreme, but I think most of Houston can probably expect to see 0.5 to 2 inches of rain between Sunday and Wednesday or so. Increased cloud cover should also help to keep highs by Sunday or Monday in the low 90s. Overall, warm, humid, summer-like weather will continue at least into next weekend.

National Hurricane Center 5-day outlook for Thursday morning.

Tropics

There are a couple of yellow blobs on the National Hurricane Center’s outlook for the next five days near the Gulf of Mexico, with 20 and 30 percent chances to develop into tropical depressions or storms over the next five days. Right now we don’t anticipate either developing into strong tropical systems, but these will be helping to drive the rain chances we mentioned earlier, beginning perhaps on Sunday.

Here comes a dying front, and at least 10 more days of summer

Today is such a disappointing day, my friends. As we look off to the west, we’re going to see an approaching front that, by all appearances, is going to die on our doorstep. The map below shows the likely extent of the front’s cooling by Thursday morning at 10 am CT. If the front makes it any further eastward—which is possible, although not particularly likely, we’ll consider ourselves lucky. The crushing part of all this is that our next chance for a real front probably will not come for another 10 to 12 days.

24-hour apparent change in temperatures shows the front’s extent by Thursday morning. (Weather Bell)

Wednesday

Today will be a day much like Tuesday, which is to say partly sunny skies with a decent chance of rain showers. However the heaviest rains will remain west of our region, over Central Texas, along the approaching front. The additional clouds should help to moderate temperatures a bit locally, with highs perhaps only reaching the low 90s. The front itself will likely bring a wind shift overnight, as winds blow from the northeast. But alas, this is likely to bring little sensible change in the weather in Houston.

Thursday

If you live north or west of Houston you may have some slight hope of a drier and cooler day, but for the rest of us Thursday will likely be a hot and sunny day with highs in the mid-90s. Rain chances will be in the 40 percent range. Thursday night may see some moderate regional cooling overnight, which is to say low- to mid-70s rather than upper 70s. And that will be the probable extent of the front’s influence on our weather—enjoy!

Friday morning’s low temperatures across the region. (Pivotal Weather)

Friday and Saturday

Summer continues, with a pair of sunny days, highs in the mid-90s, and relatively low rain chances.

Sunday and beyond

An upper-level low pressure system may combine with increased moisture at the surface to drive more widespread showers from the Sunday through Tuesday period next week, although our overall confidence in the details is low. My yard could use a few inches of rain so I’m hoping this particular forecast verifies.

Tropics

There has been no real change since Matt’s excellent overview posted on Tuesday. We still see no immediate threats to the Gulf but we’re remaining watchful as we reach the peak of the 2020 season.

Widespread showers possible today, front likely to miss on Thursday

Good morning. We’re now into the second week of September. A few of us had a friendly debate on Twitter this weekend about whether August or September was the worst month of the year in Houston, weather-wise. I’m definitely on Team August, for the simple reason that at least in September there is hope for a front and a hint of fall. Matt and several others said September is the worst for the very reason that some semblance of fall should be here in September, but it often is not. So what do you think? In any case, this week will be difficult as we watch a dying front approach the area, but likely not make a significant impact on our weather.

Tuesday

For some, this will be quite a wet day. We should see on-and-off rain showers across much of the area with a moist air mass and small feature in the atmosphere that will promote rising air. Some areas may see 1 to 2 inches of rainfall, while others see little to no precipitation from these hit-and-miss showers. Where it’s not raining, partly sunny skies should help to push high temperatures into the low-90s. Low temperatures Tuesday night will be in the upper 70s to around 80 right along the coast. Winds will be light out of the southeast.

NOAA forecast for cumulative rainfall between now and Thursday morning. (Weather Bell)

Wednesday

This is another potentially wet day as the overall air mass remains fairly unsettled upstream, with a fairly strong front pushing into Texas. This may help generate some additional showers and thunderstorms over the Houston area, keeping highs again to around 90 degrees or perhaps a little bit higher.

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