Puerto Rico faces a combination of heat, humidity, showers and hazardous maritime conditions on Tuesday, with the greatest flood risk concentrated in the south and southeast, where repeated heavy showers could cause flash, urban and small-stream flooding, according to the National Weather Service (NWS) in San Juan. A heat advisory is in effect for Puerto Rico and the US Virgin Islands because of elevated daytime temperatures, particularly in coastal and urban areas.
Overnight, showers and thunderstorms moved from Caribbean waters toward the island’s southwest, producing periods of moderate to locally heavy rain; minimum temperatures stayed above usual October values. Southeast winds could carry showers toward exposed sectors, with more precipitation expected in the afternoon and evening. Isolated thunderstorms may produce lightning and locally intense rain.
On northern beaches, breaking waves of 8 to 12 feet were reported overnight; buoys at Rincón, Arecibo and San Juan registered significant wave heights of about seven, five and six feet, respectively, with north swell periods of 12 to 13 seconds. Higher-than-normal astronomical tides combined with strong swell could cause localized coastal flooding at high tide on low-lying north coast land.
Warm, humid conditions last through Wednesday, with the heaviest rain then favored for the interior and west. A upper-level low-pressure system approaching Thursday could change the pattern, though GFS and European ECMWF models project less moisture, suggesting smaller rain accumulations while warm temperatures persist.