Hydrologic Outlook issued May 16 at 4:25PM AST by NWS San Juan PR

ESFSJU

An upper-level trough moving across the Dominican Republic, combined
with abundant moisture, will result in the development of showers
and thunderstorms across the local islands today and Saturday.

Today, showers are expected to develop across the islands, with the
highest accumulations across the interior, west and northwest Puerto
Rico. Then, tonight, as the trough crosses the region, the showers
and thunderstorms will spread across the eastern half of Puerto
Rico, including Vieques and Culebra, and also over the Virgin
Islands. This activity is expected to continue on Saturday too, but
the weather is expected to improve on Sunday, as the trough departs
toward the open Atlantic waters.

Based on the latest guidance, there is a moderate confidence in the
forecast (40-60%), and the rainfall amounts are still expected to
range from 2 to 4 inches with locally higher amounts.

Due to already saturated soils and rivers and tributaries running
well above normal levels, there is a risk for flooding across Puerto
Rico and the Virgin Islands through Saturday. Additional impacts
include landslide, urban, and flash flood in areas with the heaviest
amount of rainfall.