Puerto Rico could see an increase in showers and thunderstorms during Sunday and Monday afternoons, mainly in the interior and north of the island, according to the National Weather Service (NWS) forecast office in San Juan. A low-pressure system in the middle and upper levels of the atmosphere, located northeast of the region, would weaken the influence of a high-pressure zone and favor showers and thunderstorms during the afternoons and evenings of both days.
The combination of additional moisture, daytime heating and wind convergence could produce more intense rain and strong thunderstorms in interior and northern sectors. Weak winds could make some rain cells move slowly or redevelop over the same areas, raising the chance of significant localized rainfall accumulations, so the NWS does not rule out flooding in susceptible sectors where showers persist.
Early Sunday, passing showers are possible mainly in areas exposed to east and southeast winds, with heavier rain and localized flooding potential in the afternoon. The rainy pattern could continue Monday afternoon and evening, again concentrated in the interior and north. The NWS said it updated its hazardous weather outlook to reflect the increased potential for thunderstorms and flooding Sunday and Monday.