TROPICAL STORM GAMMA AND THE CARIBBEAN DISTURBANCE ARE LIKELY TO INTERACT IN THE GULF

As Tropical Storm Gamma moseys around the Gulf of Mexico near the tip of Mexico’s Yucatán Peninsula, Tropical Disturbance #1 is hot on its heels and gaining as it treks across the Central Caribbean. If the disturbance develops as expected, the two circulations will likely deflect and effect each other as they dance around the Gulf.

Tropical Storm Gamma is back over water after a trip yesterday over the northern part of the Yucatán Peninsula. The Gulf water is plenty strong for strengthening, but the storm is jamming up against significant dry air, the upper-level winds are becoming increasingly hostile, and Tropical Disturbance #1 is coming along to mess with its circulation. As a result, significant intensification is not expected.

The question of intensification is not clear-cut, however. Not only can a close interaction affect each storm’s track, the mutual circulations can also affect each other’s intensity. This puts an extra layer of uncertainty on top of the forecasts for each of the systems.

A separate broad circulation over Central America will encourage Gamma to drift to the south, then eventually Disturbance #1 is forecast to come help push it in that direction as well.

Since the steering currents are very weak, nudges can make a noticeable difference in the direction a storm travels. If Disturbance #1 can develop a well-defined circulation in the western Caribbean as forecast, it will give Gamma a good shove to the south. At the same time, Gamma will deflect the disturbance, or whatever it becomes, to the north. So the odds favor Gamma ending up in the southwestern Gulf with the disturbance farther north in the central or northern Gulf of Mexico.

All of that is contingent on Tropical Disturbance #1 developing a well-defined circulation in the western Caribbean. Its currently disorganized, torn apart by a narrow band of very hostile upper level winds. Once it clears that hurdle in a couple of days, however, the opportunity to do-si-do with Gamma will begin, with the potential for the disturbance to develop into a tropical depression or tropical storm in the middle of the Gulf about Thursday.

If its top winds reach 40 mph or higher, it will be named Tropical Storm Delta.

Nothing will happen fast, but everybody around the Gulf coast needs to stay aware.

Farther east in the Atlantic, the National Hurricane Center is noting two other disturbances. Neither has a high chance of developing, but Disturbance #3 could end up part of a moisture surge that moves across the northern Caribbean islands and the Bahamas. It might be part of a general increase in moisture across Florida in about a week.