“Flash Flood Alley,” which includes San Marcos and Hays County, is a combination of several risk factors. In October, the region is susceptible to a mixture of weather elements from the Pacific Ocean and the Gulf of Mexico. The addition of seasonal cold fronts just adds to the dangerous mix. City of San Marcos graphic
It’s not uncommon during the month of October for cold fronts to collide with moisture from the Pacific Ocean and Gulf of Mexico — in fact, so far this year it’s happened all around us.