Heavy rain associated with a tropical disturbance currently located off the eastern coast of Mexico just northeast of Tampico will move into southeastern Texas between Tuesday night and Thursday morning. The disturbance remains disorganized with most of the rain well to the northeast of the system. On radar, the heaviest rains are currently offshore just east of Corpus Christi and extending south into northern portions of Mexico.
Despite relatively low wind shear and warm sea surface temperatures, the disturbance has had a difficult time organizing and there is only a modest chance it will reach tropical depression strength before making landfall in Mexico Tuesday night or early Wednesday morning.
For our region, the problem is rainfall. A high pressure system keeping the disturbance moving northwest will eventually erode and the system will begin to pull north and eventually northeast Wednesday and Thursday. That should bring rain and thunderstorms up the Texas coastline through the Houston area.
The National Weather Service is calling for widespread 2-4 inches of rain between Tuesday and Thursday with pockets of larger amounts up to 6 inches. At this point, it appears the heaviest rain chances will remain mostly offshore and near the immediate coastline. The closer you are to the coast, the better your chances of significant rainfall. The storm will also bring higher-than-normal tides to Galveston and the Bolivar Peninsula.
Fortunately, the system should move through quickly and clear out by early Friday. Given the general location of the storm's rainfall, it could be a bit sooner than that for Houston and areas south as the storm tracks its way into Louisiana and the lower Mississippi Valley.
Because we haven't had a lot of rain over the past couple weeks, we can certain absorb even 5 or 6 inches of rain without any problems. But heavier storms are capable of producing 2-3 inches per hour, which would certainly cause some flash street flooding, so be cautious, particularly on the roads.