The National Weather Service (NWS) in San Juan reported on Monday flooding on Shuford Avenue in Caguas and landslides on PR-156 in Aguas Buenas, while a flash flood warning remained in effect for five towns in and around the San Juan metropolitan area. Emergency management authorities confirmed the water on Shuford Avenue and the Aguas Buenas landslides at 4:54 PM, after heavy rain from thunderstorms that hit the region.
Between 2.5 and 4.5 inches of rain had accumulated in the affected areas, and flash flooding was already under way. A US Geological Survey (USGS) gauge recorded 18.15 feet on the Cañas River in Caguas, reaching the minor flooding stage. Though the intense rain had eased, the NWS warned that runoff continued and could cause more flooding.
The flash flood warning was to remain in effect until 5:30 PM for Guaynabo, southern San Juan, western Trujillo Alto and parts of northeastern Caguas and Aguas Buenas, with Bairoa also listed among the areas at risk. The NWS said flash flooding could affect streams, creeks, urban areas, highways, streets, underpasses and low-lying sectors with poor drainage.
The update differed from a 3:27 PM warning, when Doppler radar estimated 2 to 3 inches of rain and flooding was still considered developing or imminent. The NWS urged drivers not to cross flooded roads and to use alternate routes, particularly in mountainous areas, recalling that most flood deaths occur inside vehicles.