A non-tropical storm over the Gulf of Mexico, which is helping to steer Humberto east of the United States may evolve into a tropical system and drift toward Texas early this week.The storm is currently situated in the middle levels of the atmosphere and will have to spin down to the surface and acquire tropical characteristics before it can be dubbed a tropical depression or storm. Sometimes systems of this nature evolve into a hybrid or sub-tropical storm.Rapid strengthening of this large system over the Gulf of Mexico is not anticipated before moving onshore. But it is possible it becomes a tropical or sub-tropical depression before moving inland later Monday or Tuesday along the Texas coast.Regardless of classification, the large circulation will stir up the Gulf of Mexico as it drifts westward. Expect seas and surf to build from the upper Gulf coast to the western Gulf coast into Tuesday. An uptick in the frequency and strength of rip currents is likely. Pockets of showers and thunderstorms being produced by the storm already will propagate westward in waves along the northern and western Gulf coast.Boaters, fishing vessels and rig operators should be prepared for increasing squalls and building seas, which will shift westward into Tuesday.There is the potential for enough rain to fall along the Texas and northeastern Gulf coast to trigger urban and flash flooding from Monday to Tuesday. Exactly how significant this becomes will depend on the track and strength of the feature as it moves inland.AccuWeather meteorologists will continue to monitor the system over the Gulf of Mexico, as well as Humberto and other features over the Atlantic Basin.Download the free AccuWeather app to stay alert of tropical weather advisories. Keep checking back for updates on AccuWeather.com and stay tuned to the AccuWeather Network on DirecTV, Frontier and Verizon Fios.