Intense heat, passing showers and afternoon thunderstorms in the interior and western areas of Puerto Rico will dominate Monday’s weather, the National Weather Service (NWS) said, while it keeps watch on flooding risk and dangerous rip currents at several beaches. Early Monday, passing showers are expected over the U.S. Virgin Islands and eastern Puerto Rico, which could pool water on roads and in poorly drained areas.
Heat indexes could exceed 100 degrees Fahrenheit in urban and lower-elevation areas of Puerto Rico and the Virgin Islands, and the NWS recommended staying hydrated and taking precautions against heat-related illness. Daytime heating, available moisture and converging sea breezes will favor showers and thunderstorms in the afternoon, especially over the interior and west. High atmospheric moisture could bring heavy rain capable of urban and small-stream flooding.
The pattern continues into early Tuesday, though drier air in the mid-levels will partly limit storm development. Flood risk will stay elevated in the west and northwest on both days, and conditions could reach criteria for a heat advisory, particularly Tuesday. Seas will run three to five feet, occasionally six feet, on Monday and Tuesday, and small-craft operators were urged to use caution.
From Wednesday, a low-pressure system over the western Atlantic is expected to weaken local winds. Rip current risk is moderate on the north and east coasts, Culebra and the U.S. Virgin Islands, low elsewhere, and could extend Monday to the northwest coast and Vieques. Beachgoers should seek shelter at the first sound of thunder.