The National Hurricane Center in Miami, in a 1 p.m. Monday update, reports that a broad area of low pressure, known as Invest 91, over the south-central Gulf of Mexico lacks a well-defined center but continues to have potential to become a tropical storm at any time.

The system is expected to reach the Texas coast sometime Tuesday, and could affect western Louisiana with winds and heavy rain. The system has a 90 percent chance of becoming a tropical depression or storm within 48 hours, the center said. If it becomes a storm, it would be named Bill.

Thunderstorm activity continues to become better organized this afternoon, the NHC said, and the low

will very likely become a tropical storm this afternoon or this evening as it continues moving to the northwest.

Forecast models indicate that the system will stay on a northwest track moving toward the Texas coast and could bring heavy rain to western Louisiana.

A hurricane hunter aircraft investigating the system reports the system is producing winds of 45 mph or so to the east of the elongated trough axis. Interests in and along the northwestern Gulf of Mexico should continue to monitor the progress of this system, NHC said. Tropical storm conditions are likely along portions of the middle and upper Texas coast, and possible in extreme southwestern Louisiana on Monday night and Tuesday. The system is also likely to bring heavy rainfall with possible flooding across portions of eastern Texas and western Louisiana.