Category: Tropical weather

Just a quick afternoon update to note that the forecast for Tropical Storm Barry has not changed appreciably today. While it shows some signs of getting its act together, the strongest winds remain far from the storm’s center. As of 4pm CT maximum sustained winds are 40mph.

The latest model guidance continues to suggest that either a strongish tropical storm (more likely), or possibly a weak hurricane, will move into Louisiana on Saturday. The primary threat is heavy rains, with the potential for an additional 10 to 20 inches of rainfall across already sodden areas. Of further concern is that the Mississippi River is already swollen due to drainage from flooded Midwestern areas. Finally, there is the threat of storm surge, particularly along the Atchafalaya River and Shell Beach.

NOAA rain accumulation forecast for now through Monday. (Pivotal Weather)

In regard to Barry, the greater Houston area should remain in the clear, with only perhaps 40 to 50 percent rain chances this weekend—higher near the coast, lesser inland—and probable accumulations of 1 inch or less. Galveston will be more susceptible to higher winds and thunderstorms this weekend than, say, Katy, but the entire Houston region is likely to lie on the far periphery of Barry’s action. Tides are unlikely to be a significant problem, although rip currents could be problematic.

We’ll have a full update in the morning.

Good morning. As of 4am CT, the system in the Gulf of Mexico has nearly organized into a tropical depression (named Barry), and likely will become one later this morning or early this afternoon. While Texas isn’t entirely out of the woods, as there remains some uncertainty in the track and intensity forecast, this increasingly looks like a threatening situation for Louisiana. Because the state is next to Texas, and we have received so many questions from people living in, or traveling through Louisiana, we will continue to offer comprehensive coverage of Barry as the storm develops. If you’re living in Houston, please continue to pay attention to forecasts for the next couple of days, as tropical weather invariably offers up surprises. However, it’s probably safe to go about your business as usual this weekend.

Satellite image of the tropical system shortly after 3am CT Thursday. (NOAA)

Track

Confidence is increasing in the forecast track for a couple of reasons. First of all, we’re now likely only about 2.5 days away from landfall (likely along the Louisiana coast between Lake Charles and New Orleans), and errors for such a storm are typically less than 100 miles, even given the uncertainty with Barry. Secondly, although Barry has not yet formed a distinct center of circulation, there is nonetheless a decent clustering of ensemble members of the global models around such a solution. So a Louisiana landfall is likely for Barry, but not a certainty.

National Hurricane Center track forecast for the Gulf system as of 4am CT Thursday.

Intensity

Because Barry has not yet organized into a tropical storm, and perhaps only has a couple of days remaining sufficiently offshore, this should help to set a limit on its intensity. The official forecast still brings Barry to minimal Category 1 hurricane status prior to landfall, but confidence isn’t particularly high.

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Eric and I had a conversation this spring to discuss some new ideas for the site, and ways to help readers navigate hurricane season. We absolutely feel people’s uneasiness every time it rains here, and a general sensitivity to the rumor and speculation that springs to life during hurricane season. So we have decided that every week or two, we will publish a more in-depth outlook for tropical activity in the Atlantic Ocean, Caribbean Sea, and Gulf of Mexico so that you understand what’s happening, and what could happen in the next couple weeks.

Tropical outlook in a sentence

Tropical development is unlikely over the next week or so across the Atlantic Basin, but we are eyeing July for a possible increase in activity.

Near-term summary

Historically, we would watch the Bay of Campeche and Gulf this time of year for development.

Historically, storms have formed in the Gulf and Bay of Campeche in the final third of June. (NOAA/NHC)

As of now, no tropical activity is expected over the next week, as conditions should remain mostly unfavorable for storms to develop in those areas and elsewhere.

Looking at satellite imagery from Tuesday morning, we have a couple tropical waves moving across the eastern Caribbean and a couple disorganized waves elsewhere.

The tropics show a few disorganized disturbances and mostly calm conditions today. (College of DuPage)

None of these waves is a candidate for development as of right now, and if anything, they should fizzle out and stay safely away. So: Good news, as we just don’t see much of anything out there.

Weather model fantasy-land

One of the biggest hurdles to good tropical information during hurricane season in the social media era is a tendency for folks to mention a model solution with zero context or just because it shows something extreme. You’ll see something like, “This model is just one solution but it shows a category 10 hurricane in the Gulf in 15 days! You probably shouldn’t believe it, but here it is anyway.”

Is there anything showing up on the models in days 10-15? Not at this time. The GFS model, which is the most frequent offender with fantasy-land storms is quiet right now. The GFS tends to have a bias early in the hurricane season, and then again later in the hurricane season. The bias is worst in May and early June, where it can often spin up systems in the Caribbean that never materialize. I tried to run the math on it last season, and during the month of May 2018, 79% of the time the GFS showed a storm beyond day 10, it never materialized.

Now, the GFS model was recently upgraded which should hopefully lead to reduced false alarms, but we won’t know much about that in practice until next May. Within the season, it still seems to show more false alarms than not, and Eric and I try to sort through the noise for you. Let this just serve as a reminder to be cautious of extreme modeled solutions posted on social media without much context.

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June 1 marks the “official” beginning of the Atlantic hurricane season, and although it often begins quietly, we start this season with an eye on the Gulf of Mexico. For a couple of days now, the European model ensembles have been hinting at the formation of a tropical system in the southern Gulf of Mexico, and now this appears more likely. On Saturday morning, the National Hurricane Center raised to 50 percent the possibility of a tropical depression or storm forming there during the next five days.

As of 7am CT on Saturday, the National Hurricane Center forecasts a 50 percent chance of development.

All the usual caveats apply here: It is difficult to have much confidence in the movement of a system that has not yet formed, and it will also be affected by its proximity to the Mexican coast. With that said, generally, we expect this tropical system to move to the west-northwest over the next few days, perhaps toward Tampico (along the country’s east coast on the southern Gulf of Mexico) or Brownsville.

Assessing where this tropical system may go. (Tropical Tidbits/Space City Weather)

What this all means for Texas in general, and Houston in particular, for the coming week is far from certain. We still expect partly to mostly sunny skies through at least Monday, with hot temperatures in the mid-90s. But our weather beyond this, to some extent, will be determined by the movement of this tropical system. The ceiling for this system, in terms of winds, is low, so our primary concern will be the potential for moderate to heavy rainfall.

Eventually, it is going to get pulled north, so we can have some confidence in wet weather for Texas next week, but confidence for where, and how much rain, remains low. I’d say the best chance for heavy rainfall in Houston would come from late Wednesday through Thursday, but there are so many variables we’ll just have to see. For now, we’re not too concerned about the potential for any flooding in the greater Houston area—forced to guess, I’d say 1-3 inches of rain—but obviously we’ll be monitoring this for you.