The US National Weather Service (NWS) has issued a flash flood warning for San Antonio and surrounding areas due to sustained heavy rainfall. The warning is in effect until at least 05:00 on January 22. There is a potential for flooding in low-lying communities near rivers, streams, and creeks, as well as urban areas with overwhelmed stormwater drainage systems. Landslides are also possible in hilly or mountainous areas with saturated soil.

The heavy rainfall could result in localized business disruptions and transportation, electricity, and telecommunications disruptions. Some businesses may not operate at full capacity due to flood damage and possible evacuations. It is advised to monitor local media for weather updates, confirm travel plans, and make allowances for potential delays and supply chain disruptions. Drivers should not attempt to drive on flooded roads. Residents are also advised to charge their battery-powered devices in case of prolonged electricity outages.

Although severe thunderstorms are not expected, there could be a few rumbles of thunder. Wind speeds are expected to remain light, and the chance of hail is low. It is important to stay informed and take necessary precautions to stay safe during this weather event.