First, I would like to send my good thoughts to Houston and all the other communities and towns that have been impacted by Harvey across Texas and Louisiana. If there is anything Firsthand Weather can do to assist you all, please do not hesitate to send us a message!
The rain has begun to shift eastward to far eastern Texas, and towards Louisiana and Mississippi. This will allow for better weather conditions as damage assessments and cleanup begins. Unfortunately, numerical guidance is indicating the potential for deep tropical moisture to move into coastal areas of Texas and Louisiana by mid next week. A moisture axis in the southern Caribbean will move over the Yucatan Peninsula late this week/early weekend into the southwestern Gulf of Mexico. This may lead to the development of a surface low off of the Texas coast by early to mid next week.
This would aid in deep tropical moisture potentially being pulled into Texas as an upper-level low is situated across the Panhandle of Texas–leading to precipitation chances. At this time, it appears a surface cold front will be situated somewhere across Texas, which could enhance precipitation, too. As the low moves eastward, it will aid in precipitation chances for Louisiana.
Current moisture axis in Caribbean (GFS)
Deep moisture in southwestern Gulf of Mexico by Monday morning (GFS)
Deep moisture in southwestern Gulf of Mexico Wednesday afternoon (GFS)
Precipitation forecast through 7 days from NWS (please note: this map will change over the next few days and it looks plausible that higher precipitation amounts will shift northward)
This is still several days out, so a lot will change; however, this scenario is plausible and needs to be closely monitored. It’s to early to determine the strength of this low, but it is possible a tropical cyclone (TD or TS) could evolve. Any additional rainfall next week will quickly cause flooding. Keep checking back for updates!