All signs are showing an increase in activity across the Atlantic basin as we near the astronomical peak of tropical cyclone activity, which is September 10. There is an area to watch over the Gulf of Mexico associated with a tropical wave currently affecting the Greater Antilles. There is also the 6th potential tropical cyclone brewing. This aggressive wave will likely organize into Tropical Storm Florence later in the day Friday while delivering tropical storm conditions to portions of the Cabo Verde islands. Beyond then, what will likely be Florence will track into the open waters of the Atlantic. We’ll monitor this storm for potential impacts downstream, but that chance is thankfully low at this time.
Our focus in this article will be the tropical wave tracking from the Greater Antilles to the Gulf of Mexico. This wave will bring heavy rain and gusty winds to islands like Puerto Rico, Hispaniola, and the Bahamas between now and this weekend. It will then track over South Florida Sunday into Monday, still as a trough of low pressure. This trough will contain an ample amount of moisture with precipitable water values possibly exceeding 3 inches. That indicates a highly moist environment and a significant chance for heavy rain in some areas. It also suggests that rain and storms will be widespread as opposed to being isolated. Unfortunately, this will happen in the midst of the Labor Day weekend, so outdoor plans may have to be moved inside for some.
On Monday, the tropical wave will move over the eastern Gulf of Mexico after departing South Florida. By this point in time, we’ll have to watch this disturbance extra closely for tropical cyclone formation. The ensemble mean of the European model indicates about a 50-50 chance for this to happen, while the National Hurricane Center, which provides the official tropical cyclone forecasts, only gives the tropical wave a 10 percent chance of developing. Either way, if it does develop over the Gulf of Mexico next week, it will likely be weak given the unideal environment. Water temperatures are warm, which is a positive for development, but wind shear will likely be present, which tends to inhibit development.
By midweek, this tropical entity will approach the central Gulf Coast, possibly moving inland between Louisiana and Texas. Some of the guidance even suggests it tracks toward South Texas and stalls there for days, dumping heavy rain. That’s not the likely scenario at this time, but definitely a possibility. These kinds of systems are quite difficult to forecast more than a few days out in time. The key thing to know is that next week will be unsettled along the US Gulf Coast, and that you should monitor the forecast.