Heating up: NWS says more tropical cyclones could impact South Texas

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Tropical Storm Alberto, which last month ushered in beneficial rainfall for the Rio Grande Valley, could be just the first of several tropical cyclones to affect the lower Texas coast this Atlantic hurricane season, according to the latest seasonal outlook from the National Weather Service Brownsville-RGV station, released June 28.

Barry Goldsmith, NWS warning coordination meteorologist, wrote that although the “peak of potential landfalls remains from late July through mid-September, though in a busy season, we can’t rule out any window between July 1 and Sept. 30.”

The National Oceanic and Atmospheric Administration is predicting an above-normal season, with 17 to 25 named storms, eight to 13 hurricanes and four to seven major hurricanes.

For South Texas, the impact of any tropical storms this season on roads, buildings and other local infrastructure, and water supplies for agriculture and municipalities, depends on where they make landfall and how far they penetrate inland, Goldsmith said. The effects could range “from beneficial rain to excessive flooding (or) from an historical event to little impact,” he said.

“All possibilities are on the table for this season,” Goldsmith said.

As for the impact of Alberto and the tropical wave that came right behind it, it all came down to location, he said. Repeated bouts of heavy rain quickly pushed up reservoir levels at El Cuchillo and Marte Gomez (located along the Rio San Juan south of Starr County into western Tamaulipas and south-central Nuevo Leon in Mexico), but mostly missed Amistad and Falcon reservoirs — critical water sources for the Valley’s municipalities and agriculture, Goldsmith said.

As of June 30, Amistad and Falcon combined were still at or near record-low levels, he said. If the headwaters of the Rio San Juan see further rounds of flooding rainfall into mid-July, the two associated reservoirs could approach capacity, though any water distribution from the Rio San Juan into the Rio Grande due to releases from El Cuchillo and/or Marte Gomez would be managed by Mexico, Goldsmith said.

There’s still the potential for sufficient rain to fall in the headwaters of the lower to mid-Rio Grande Valley basin that Amistad and Falcon are able to recover, though there’s only “low to medium confidence in this outcome,” he said.

“Alberto (and the) secondary wave showed us that an active tropical window can still leave these headwaters largely empty,” Goldsmith cautioned.

Last month’s precipitation likewise did little to bring down temperatures, which were expected to largely remain in the top-five hottest Junes on record for Valley communities — Brownsville and Weslaco coming in first, McAllen at third hottest on record and Rio Grande City in seventh place. Still, the rain did knock back the Valley’s moderate drought conditions, for now.

Meanwhile, Category 4 Hurricane Beryl slammed into the Caribbean island of Carriacou Island around 10 a.m. CDT Monday on its way to the Yucatan Peninsula, where it is expected to arrive Friday morning, before entering the Bay of Campeche as a tropical storm Saturday morning.

Goldsmith said a “mid-level steering ridge” will keep Beryl more or less on its east-to-west course toward the Yucatan over the next five days.

“The latest forecast guidance indicates there will be increasing shear as Hurricane Beryl moves west-northwest across the Caribbean Sea, which will allow for a gradual weakening,” he said. “However, Beryl is expected to remain a powerful hurricane through late this week.”

Beryl has already made history as the first June hurricane to hit Category 4 since record-keeping began in 1851, the farthest east a tropical storm has ever hit Category 4, and the first storm before September to go from tropical depression to major hurricane in less than 48 hours.

Also as of Monday afternoon, the National Hurricane Center was monitoring a low-pressure area several hundred miles southwest of the Cabo Verde Islands, which are off the coast of West Africa in the Central Atlantic, Goldsmith noted, adding that conditions are “marginally conducive” for the system to developing into a tropical depression by the middle of this week as it moves west. There is a medium (60 percent) chance for tropical development over the next seven days, according to NHC.

It’s too soon to tell what, if anything, all this means for the Valley, Goldsmith said.

“The track and intensity forecast beyond five days is highly uncertain,” he said. “It is too early to determine whether there will be any impacts to deep South Texas.”

With Valley in cone of uncertainty, NWS says don’t wait on storm preparation