Invest 96L likely to become a Debby, a serious flooding threat to USA
A well-defined area of low pressure located just north of the Yucatan Peninsula, dubbed Invest 96L, is steadily organizing this afternoon and seems poised to become a tropical depression over the next day or so. Satellite imagery loops reveal that a large area of shower and thunderstorm activity across much of the Central and Eastern Gulf of Mexico, and surface observations from the Yucatan Peninsula and surrounding locations show that barometric pressure readings are steadily falling. In addition, latest wind shear product maps reveal that wind shear affecting the low-level center of 96L has decreased significantly thanks to a small upper-level anticyclone positioned atop of it. The latest National Hurricane Center Tropical Weather Outlook gave the invest a High chance, 70%, of becoming a tropical cyclone over the next 48 hours; I agree with these percentages.
Figure 1. Afternoon visible satellite imagery of Invest 96L.
The forecast for 96L
Invest 96L poises a significant threat to the United States. As aforementioned, the disturbance has an anticyclone positioned directly atop the low-level center. Sea Surface Temperatures in 96L's potential track(s) are 28-29 °C; wind shear is expected to be below 15 knots throughout the entire forecast period (120 hours). In addition, the latest Precipitable Water Loop from the University of Wisconsin shows that the disturbance is embedded within a large moisture envelope, shielding it from any potential dry air intrusions. Other than time and its current broad nature, I see no reason why 96L will not gradually, or maybe even rapidly, strengthen over the next few days. A hurricane in the Gulf of Mexico is definitely not out of the realms of possibility.
As for track, it is still very much unknown. Until we get an actual tropical cyclone, models will continue to perform what is called the "windshield wiper" effect--that is, switching drastically from run to run. However, what 96L's track boils down to depends on 1.) the strength of the future ridge across Texas, 2.) the strength of the incoming trough, and 3.) the strength of the actual tropical cyclone. The entire USA Gulf Coast needs to watch this system closely and begin preparing for a potential hurricane.