The National Weather Service on Friday issued a flash flood watch for the U.S. Virgin Islands, along with portions of Puerto Rico, effective through Sunday evening.
According to the NWS, the advisory was issued due to the potential for periods of heavy rains, flash flooding and mudslides, expected to continued at least until Sunday night.
The NWS in San Juan expanded the flash flood watch to include St. Croix, St. Thomas, St. John, Culebra and Vieques.
“Moisture advection from the south and favorable upper-level dynamics will result in periods of showers and thunderstorms across the islands through the weekend,” the NWS said. Advection is “the usually horizontal movement of a mass of fluid (such as air or an ocean current,” according to the Merriam Webster dictionary.
“These showers and thunderstorms are expected to drift slowly across the area, increasing the risk for flash flooding,” the weather service warned. “These heavy rains will bring rapid rises in area rivers and streams and will make transiting on roads and low lying areas impassable.”
The NWS said the rains “also may trigger dangerous mudslides and debris flow without warning.”
A flash flood watch means that conditions may develop that lead to flash flooding. The service urged residents to monitor forecasts and be prepared to take action should flash flood warnings be issued.