Tropical Storm Zeta formed in the western Caribbean very early Sunday morning and is set to drift north and unleash wind, heavy rainfall and, potentially, ocean surge concerns as it approaches the U.S. Gulf Coast Tuesday night and Wednesday.
Zeta is most likely to come ashore the Gulf Coast on Wednesday at tropical-storm strength, but there’s an outside chance that it could cross the coast as a hurricane. According to the Hurricane Center, Zeta “could bring storm surge, rainfall, and wind impacts to areas from Louisiana to the Florida Panhandle."
The landfall zone includes areas in Louisiana hit hard by hurricanes Delta and Laura as well as parts of Alabama slammed by Sally.
Portions of the beleaguered Pelican State have spent more than three weeks in 2020 inside the National Hurricane Center’s cone of uncertainty, the zone where forecasters have predicted storms could reasonably track.
Zeta is likely to become the 11th named storm to make landfall in the United States in 2020, extending the record for most in a year, which was broken by Delta earlier this month.
Once it comes ashore, Zeta will evolve into a heavy rain threat over the Southeast, thanks to the anticipated interaction of the storm’s remnant tropical moisture with an approaching cold front.
On satellite imagery, Zeta was beginning Sunday with vigorous thunderstorm activity north of Honduras in the western Caribbean. The system’s center had actually reorganized south of its previous location in an effort to follow the most robust thunderstorm activity and lifting motion. That process increases the odds of Zeta striking the Yucatán Peninsula, an area also slammed by Delta and Tropical Storm Gamma earlier this month.
An aircraft reconnaissance mission into Zeta early Sunday found winds up to 40 mph shortly before 5 a.m., supporting its earlier upgrade to tropical storm status. Warm sea-surface temperatures, which contain plenty of energy to support Zeta’s intensification, are present where Zeta is currently lurking. As of 8 a.m. Sunday, Zeta was entirely stationary.
Effects on Mexico
A tropical storm warning is up for the western tip of Cuba, including Pinar del Rio, while watches have been issued for the Yucatán Peninsula, including areas between Tulum and Rio Lagartos, as well as Cozumel, Mexico. A widespread four to eight inches of rain is expected in those areas, as well as in the Cayman Islands and Jamaica, with the slow-moving system through Tuesday. Localized totals up to a foot are possible.
Recent forecasts continued to shift the anticipated track of Zeta farther west away from Cuba and more toward Mexico. Now, the Hurricane Center is forecasting a landfall as a Category 1 hurricane early Tuesday somewhere between Playa del Carmen and Cancun.
There are some indications that Zeta could try to sneak in some last-minute intensification before landfall and could attempt to approach Category 2 status as it churns toward the Mexican coastline on Monday night.
Reorganization over the gulf and threat to the South, Southeast
After briefly faltering following its passage over land, the system would then probably reorganize over the Gulf of Mexico and accelerate north from Tuesday into Wednesday. It will be scooped toward the Gulf Coast ahead of a mid-level disturbance arriving from the west over the southern United States.
That disturbance and associated cold front could be both a blessing and a curse. While it will probably weaken Zeta’s winds enough so that it’s a strong tropical storm or minimal hurricane upon landfall Wednesday, it could help to focus and enhance Zeta’s rainfall potential. The threat of flooding will have to be closely monitored in portions of the South and Southeast.
Landfall is most likely somewhere along the eastern Louisiana or Mississippi coastlines, but the area from the Texas-Louisiana border and the Florida Peninsula could experience storm impacts.
“While the current NHC forecast indicates that the system should weaken below hurricane strength before landfall, users are reminded that strong tropical storms can still produce significant storm surge, rainfall, and wind impacts,” the National Hurricane Center wrote.
Winds gusting over 60 mph near the coast are likely regardless, along with heavy rainfall that could affect some of the same regions drenched by Sally in mid-September.
Zeta’s eventual merger with a frontal system could bring a swath of three to four inches of rain or more into parts of the Southeast and Mid-Atlantic late in the week. Places like Atlanta, the Carolina Piedmont and even the Virginia Tidewater appear most at risk for this deluge of rainfall.
Zeta’s remnants should exit the Mid-Atlantic on Friday.