By Caribbean News Now contributor
MIAMI, USA — Tropical Storm Isaac is expected to bring storm force winds and heavy rain to parts of the Lesser Antilles from about 2:00 am Thursday morning. Tropical storm warnings are in effect for Dominica, Guadeloupe and Martinique. Tropical storm watches are in effect for Antigua, Montserrat, St Kitts and Nevis, Saba, St Eustatius, St Martin and St Maarten. Interests elsewhere in the Leeward Islands should monitor the progress of Isaac.
According to the National Hurricane Center (NHC) in Miami, at 5:00 pm EDT on Wednesday, the centre of Tropical Storm Isaac was located about 295 miles (480 km) east of Martinique and about 325 miles (525 km) east of Guadeloupe, moving toward the west near 20 mph (31 km/h).
This general motion, with a decrease in forward speed, is expected to continue through the weekend. On the forecast track, Isaac is forecast to move across the central Lesser Antilles and into the eastern Caribbean Sea on Thursday, and then move across the eastern and central Caribbean Sea through Saturday.
Maximum sustained winds remain near 60 mph (95 km/h) with higher gusts. Some weakening is forecast during the next 48 hours. Tropical-storm-force winds extend outward up to 175 miles (280 km) from the centre.
Isaac is expected to produce total rainfall accumulations of 2 to 4 inches with isolated amounts up to 8 inches across Martinique, Dominica, and Guadeloupe. Rainfall of 1 to 2 inches with isolated amounts to 4 inches are forecast across Puerto Rico and the southern US Virgin Islands, with up to an inch anticipated across the remaining Windward and Leeward Islands. This rainfall may cause life-threatening flash floods.
Tropical storm conditions are expected on Martinique, Dominica, and Guadeloupe early Thursday. Tropical storm conditions are possible within the tropical storm watch area on Thursday.
Some coastal flooding is possible in areas of onshore winds. Near the coast, the surge will be accompanied by large waves.
Swells generated by Isaac are affecting portions of the Lesser Antilles. These swells are likely to cause life-threatening surf and rip current conditions.
Effective 8 pm Tuesday, the US Coast Guard Sector San Juan set port condition X-ray for Puerto Rico and the US Virgin Islands due to the expectation of sustained gale force winds of 25 mph and gusts up to 40 mph generated by tropical storm Isaac that may arrive within 48 hours.
These ports and facilities are currently open to all commercial traffic and all transfer operations may continue while X-ray remains in effect.
Mariners are reminded there are no safe havens in these facilities, and ports are safest when the inventory of vessels is at a minimum. All ocean-going commercial vessels and ocean-going barges 500 gross tons and above should make plans for departing the port.
Vessels bound for Puerto Rico or the US Virgin Islands unable to depart 24 hours prior to threatening winds potentially making landfall are advised to seek an alternate destination.
Pleasure craft are advised to seek safe harbour. Port facilities are advised to review their heavy weather plans and take all necessary precautions to adequately prepare for the expected conditions.
If and when port condition Yankee is set, meaning sustained gale force winds are expected within 24 hours, vessel movement will be restricted.