Flash Flood Warning In Effect For VI As Tropical Wave Approaches With Showers, Thunderstorms And Gusty Winds

The Virgin Islands Territorial Emergency Management Agency said this afternoon that Invest 99L, a tropical wave making its way through the region, would stay on course and bring showers, thunderstorms and gusty winds to the territory and Puerto Rico, although the system had slowed as it neared the U.S. Virgin Islands.

At 8:00 a.m. this morning, according to V.I.T.E.M.A., satellite images, surface observations, and radar data indicated that the broad area of low pressure associated Invest 99 L was located over the northern Leeward Islands. Showers and thunderstorms have become more concentrated overnight and are showing signs of organization, but the system still appears to lack a well-defined circulation.

Although environmental conditions are currently only marginally conducive for additional development, this system could become a tropical depression at any time during the next few days while it moves west-northwestward at about 15 mph across the northern Leeward Islands, near or over Puerto Rico, Hispaniola, and the Bahamas.

USVI Impact

According to the US National Weather Service at San Juan, the tropical wave has slowed its movement to 15 miles per hour and, as of 8:00 a.m., had not reached the US Virgin Islands and Puerto Rico. Also at 8:00 a.m. today, the tropical wave was located about 150 miles east-southeast of U.S. Virgin Islands or 200 miles east-southeast of Puerto Rico.

But the USVI and eastern Puerto Rico should continue to expect showers and thunderstorms throughout the day today, with the core of the showers and thunderstorms, the heaviest rainfall, expected during the afternoon hours. Estimated rainfall amount is 2 to 4 inches with locally higher amounts in isolated areas. The northern USVI, St. Thomas and St. John, is forecasted to receive the bulk of the rainfall.

The system is producing sustained winds of 15 to 20 miles per hour with higher gusts embedded within the thunderstorms.

Seas are forecast to be 6 to 8 feet with occasional seas 9 to 10 feet across the Atlantic waters. Sustained winds of 20 to 25 knots with locally higher gusts are also expected. The highest seas are expected over the Atlantic offshore waters. There is a moderate to high risk of rip currents along the Atlantic Coastlines.

Based on the latest guidance, conditions should improve on Thursday afternoon into Friday.

A Flash Flood Watch is in effect for the USVI through midnight.

VITEMA Director Mona Barnes is encouraging the public to closely monitor this system, particularly those in flood prone areas. If flooding is observed, avoid the area.

According to Ms. Barnes, critical department and agencies remain on alert for possible flooding events. VITEMA continues to closely monitor the system and is receiving regular updates from the National Weather Service at San Juan.

A FEMA federal liaison officer is currently on the ground in St. Croix.