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