* WHAT. Flash flooding caused by excessive rainfall is possible. * WHERE. Puerto Rico, including Vieques and Culebra, and the U.S. Virgin Islands. * WHEN. From Thursday morning through Saturday morning. * IMPACTS. Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations. Creeks and streams may rise out of their banks. Flooding may occur in poor drainage and urban areas. Low-water crossings may be flooded. * ADDITIONAL DETAILS. - A series of mid-to-upper level troughs and above-normal moisture from a nearly stationary front will create ideal conditions for thunderstorm development over the next few days, with the most intense and frequent activity expected between Thursday morning and Saturday morning. Recent and expected moderate to heavy rain pulses will likely saturate soils before the peak unsettled weather period, setting the scenario for significant excessive rainfall hazard risks. Rainfall totals during this period are expected to range from 3 to 6 inches, with locally higher amounts of 8 to 10 inches across northern and eastern Puerto Rico, Vieques, Culebra, and the U.S. Virgin Islands. Elsewhere, expect rainfall amounts around 1 to 2 inches. Due to the high likelihood that any extended period of moderate to heavy rainfall will lead to flash flooding, sudden river surgespotentially causing some rivers to exceed flood-stage levelsand mudslides in areas with steep terrain, a Flash Flood Watch has been issued. Although uncertainties are present, unsettled weather conditions will likely continue from Sunday into early next week. Residents and visitors, especially those in flood-prone areas or planning outdoor activities in the coming days, are advised to closely monitor the latest weather forecasts. - Http://www.weather.gov/safety/flood
