Issued: 6:00 PM Wednesday, 12th September, 2018


At 5:00 pm, the center of Tropical Storm Isaac was located near latitude 15.4 North, longitude 56.6 West. From the image at 5:15 pm (compliments RAMMB)...The circulation is visible and the center is exposed on the western side of a re-developing band of convection on the eastern side.

Isaac is moving toward the west near 20 mph (31 km/h), and this general motion with a decrease in forward is expected to continue through the weekend. Isaac is forecast to move across the central Lesser Antilles and into the eastern Caribbean Sea on Thursday, remaining at tropical storm intensity.

 Maximum sustained winds are near 60 mph (95 km/h) with higher gusts. Some weakening is forecast during the next 48 hours.

 The estimated minimum central pressure is 1003 mb (29.62 inches)

Tropical-storm-force winds extend outward up to 175 miles (280 km) from the center.

Swells generated by Isaac are already affecting portions of the Lesser Antilles. Wave heights across SVG are increasing, with swells on the west coast possibly reaching up to 2.0m (6.5ft), while on the east coasts swells could reach up to 3.0m (10ft) by Thursday.

Latest analysis indicates that Isaac could produce total rainfall accumulations of up to 1 inch across portions of the Windward Islands; wither higher amounts across some islands. As the system progresses westward, instability with moderate to heavy showers, thunderstorm activity and occasional gusty winds can be expected by Thursday afternoon into Friday and decreasing late Saturday. Models suggest that rainfall accumulations of 50 to 75 mm (2 to 3 inches) are possible across parts of SVG during the passage of “Isaac”.

The St Vincent and the Grenadines Meteorological Services will continue to monitor this system and provide the necessary updates and/or advisories.