000 WTNT41 KNHC 200843 TCDAT1 Tropical Storm Alberto Discussion Number 11 NWS National Hurricane Center Miami FL AL012024 400 AM CDT Thu Jun 20 2024 Alberto is nearing landfall in Mexico this morning. On satellite, the system has evolved markedly from yesterday, with some rather cold cloud tops below -80 C associated with nearby deep convection just to the south of the center. However, an earlier GPM microwave pass and nighttime shortwave-IR imagery suggests the broad center is partially exposed north of bursting convection due to a bit of northeasterly shear. The final Air Force Reserve recon leg through the center overnight found peak 850 mb winds of 55 kt and SFMR winds between 45-50 kt. A blend of this data still supports an intensity of 45 kt. Scatterometer imagery received since the prior advisory suggests the wind radii have contracted some, but the circulation center remains fairly broad. The overnight recon center fixes jumped around a bit, yet Alberto appears to still be on a westward heading, but moving a little faster, estimated at 275/11 kt. Deep-layer ridging positioned to the north of Alberto is building westward and should maintain this storm motion with some additional acceleration. Thus, Alberto is expected to make landfall along the coast of Mexico shortly. The time for additional intensification is just about over, and the tropical storm should quickly weaken over the higher terrain of Mexico, with dissipation likely in 24 h, if not sooner. Alberto remains a large system and continues to produce moderate coastal flooding across portions of southern Texas. Tropical-storm conditions and heavy rainfall also will continue for northeastern Mexico, even as Alberto moves inland later today. Key Messages: 1. Users are reminded not to focus on the exact forecast track of this system. Alberto is very large with rainfall, coastal flooding, and wind impacts occuring far from the center along the coasts of Texas and northeastern Mexico. 2. Rainfall associated with Tropical Storm Alberto will begin to diminish today across southern Texas. Rainfall associated with Alberto, however, will continue to impact large regions of Central America, north across northeastern Mexico. This rainfall will likely produce considerable flash and urban flooding along with new and renewed river flooding. Life-threatening flooding and mudslides are likely in and near areas of higher terrain across the Mexican states of Coahuila, Nuevo Leon, and Tamaulipas, including the cities of Monterrey and Ciudad Victoria. 3. Moderate coastal flooding is likely along much of the Texas Coast through the morning. 4. Tropical storm conditions are expected along portions of the coast of northeastern Mexico within the Tropical Storm Warning area though this morning. FORECAST POSITIONS AND MAX WINDS INIT 20/0900Z 22.3N 97.3W 45 KT 50 MPH 12H 20/1800Z 22.1N 100.6W 30 KT 35 MPH...INLAND 24H 21/0600Z...DISSIPATED $$ Forecaster Papin