The National Hurricane Center in Miami issued its first advisory Tuesday morning on Potential Tropical Cyclone One, a weather disturbance that has been tracked for several days as it traveled across the southern Gulf of America and into northeastern Mexico before pushing into southern Texas.
The system, previously identified as AL90, is generating significant rainfall but has not yet developed a well-defined center of circulation. Forecasters say most computer models indicate the system will move back offshore overnight Tuesday, with winds expected to reach tropical storm strength by Wednesday. As a result, Tropical Storm Watches have been put in place for parts of the Upper Texas coast and southwestern Louisiana shoreline — specifically from Sargent, Texas, to Morgan City, Louisiana.
Regardless of whether the disturbance officially becomes a tropical cyclone, forecasters are warning that heavy rain and life-threatening flash flooding remain the most serious dangers. The initial wind intensity has been set at 25 knots, or about 30 miles per hour, based on surface and radar observations.
The storm is currently drifting slowly to the northeast. Forecasters expect it to pick up speed as it interacts with a broad weather trough sitting over the eastern United States. Models suggest the system will hug the Texas coastline Wednesday before moving back onshore late Wednesday or early Thursday. Forecasters project the system will dissipate by early Friday.
Upper-level atmospheric conditions are not particularly favorable for significant strengthening, with notable wind shear and the system’s close proximity to land working against it. However, a jet stream to the north and warm Gulf waters are expected to support some intensification through Wednesday. Due to the shear, the storm is unlikely to take on a classic tropical appearance on satellite imagery — instead, rainfall and winds will be concentrated heavily on the eastern side of the system.
Key hazards forecasters are highlighting include:
Flooding: Potentially life-threatening flash and urban flooding is expected along the Texas coast eastward into central Mississippi through Thursday. If rainfall is prolonged, flood threats could stretch into the weekend. Small stream and minor river flooding is anticipated along the Texas coast into southwestern Louisiana, with isolated pockets of significant river flooding possible in those areas.
Tropical Storm Threat: The system is forecast to strengthen into a tropical storm as it moves along or just off the northwestern Gulf Coast through Wednesday.
Coastal Flooding: Minor to moderate coastal flooding is expected along portions of the Upper Texas and Louisiana coastlines.
This advisory was issued by Forecaster Blake at the National Hurricane Center.
