* Updated to include tropical storm watches issued for St Martin and St Maarten in 2 p.m. NHC advisory.

FLORIDA, United States, Wednesday September 12, 2018 – Tropical Storm Isaac is on course to reach the Lesser Antilles tomorrow, but it won’t be at hurricane strength as previously forecast.

Isaac has weakened and is now carrying maximum sustained winds near 60 miles per hour, according to the National Hurricane Centre (NHC) in Miami, and is expected to weaken further as it moves toward the Caribbean.

At 11 a.m., Tropical Storm Isaac was located about 420 miles east of Martinique and 455 miles east of Guadeloupe, and moving towards the west at 17 miles per hour – a direction it is expected to continue on throughout the weekend, although with some decrease in forward speed.

“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,” the NHC said.

A tropical storm warning is in effect for Martinique, Dominica and Guadeloupe, while a tropical storm watch is in effect for Antigua, Montserrat, St. Kitts and Nevis, Saba, St. Eustatius, St Martin and St Maarten. But interests elsewhere in the Leeward Islands have been advised to continue monitoring Isaac’s progress.

Isaac is expected to bring heavy rains which may cause life-threatening flash flooding.

“The storm is expected to produce total rainfall accumulations of 2 to 4 inches with isolated amounts up 8 inches across Martinique, Dominica and Guadeloupe. Rainfall amounts of 1 to 2 inches with isolated amounts to 4 inches are expected across Puerto Rico and the southern United States Virgin Islands,” the NHC warned.

It added that swells generated by Isaac will begin to affect portions of the Lesser Antilles this afternoon.

Far out in the Atlantic, Hurricane Helene’s maximum sustained winds have weakened slightly to 90 miles per hour, and it is expected to weaken to a tropical storm on tomorrow. The hurricane poses no threat to land at this time.