By Caribbean News Now contributor
MIAMI, USA — At 5:00 pm EDT on Sunday, the centre of Tropical Storm Isaac was located about 1,390 miles (2,240 km) east of the Windward Islands, moving toward the west near 12 mph (19 km/h) and is expected to become a hurricane by Sunday night.
According to the National Hurricane Center (NHC) in Miami, the westward motion is forecast to continue through the end of the week and accelerate during the next 36 hours, with Isaac expected to move across the Lesser Antilles and into the eastern Caribbean Sea on Wednesday night or Thursday.
Maximum sustained winds have increased to near 70 mph (110 km/h) with higher gusts. Additional strengthening is forecast, but weakening is anticipated to begin by the middle of the week as Isaac approaches the Lesser Antilles.
Tropical-storm-force winds extend outward up to 45 miles (75 km) from the centre.
Meanwhile, Hurricane Florence, which is about 720 miles (1,160 km) southeast of Bermuda and about 580 miles (935 km) northeast of the northern Leeward Islands, is forecast to become a major hurricane on Monday.
However, on the forecast track, the centre of Florence will move over the southwestern Atlantic Ocean between Bermuda and The Bahamas on Tuesday and Wednesday.
Aircraft and satellite data indicate that maximum sustained winds have increased to near 85 mph (140 km/h) with higher gusts. Florence is forecast to rapidly strengthen to a major hurricane by Monday, and is expected to remain an extremely dangerous major hurricane through Thursday.
Hurricane-force winds extend outward up to 25 miles (35 km) from the center and tropical-storm-force winds extend outward up to 125 miles (205 km). Florence is forecast to become larger over the next few days.
Swells generated by Florence are affecting Bermuda and are likely to cause life-threatening surf and rip current conditions.
Tropical Storm Helene also became a hurricane on Sunday but is expected to remain over open water in the Atlantic as it continues to move away from the Cabo Verde Islands.
Finally, a combination of an upper-level trough and a tropical wave over the northwestern Caribbean Sea is producing a large area of disorganized showers and thunderstorms between Cuba and Honduras.
Upper-level winds could become somewhat more conducive for some development in a couple of days while the system moves slowly west-northwestward or northwestward.