This rainfall may cause life-threatening flash flooding. Florence has 130 miles per hour winds, enough to make it a risky Category 4 hurricane.
On the forecast track, Isaac is forecast to move across the central Lesser Antilles and into the eastern Caribbean Sea later today, and then move across the eastern and central Caribbean Sea through the weekend.
RTE reports that the National Hurricane Centre in the United States said that the weather event will be packing wind speeds of 140km/h, but that by the time it reaches the UK and Ireland, it won't be as severe as it has been elsewhere.
However, it is not expected to bring the severe weather seen during Storm Ophelia last October, which caused widespread damage and left three people dead. As of Wednesday afternoon, Helene had maximum sustained winds near 90 miles per hour. Some flooding was forecast early in the day for parts of North Florida, but those forecasts were adjusted later to include high swells and minor coastal flooding at high tide.
Florence is now 485 miles from Wilmington, North Carolina.
They warn that some roads and bridges may close.
The NHC at 11 a.m. on September 12 has issued warnings for Tropical Storm Isaac, which is still moving west about 420 miles east of the island of Martinique. It will continue to move to the west and away from the V.I. during the overnight hours.
Its warning, in force between 6pm on Monday and midday on Tuesday, said "very strong winds" could pose the risk of "injuries and danger to life" because of flying debris. "Prepare for long power outages".
The National Hurricane Center (NHC) said in their 11 a.m. advisory that not much change in strength is forecasted for Isaac during the next few days, but it is expected to be near hurricane strength again as it moves through the Lesser Antilles, with some weakening forecasted afterward on Friday.
"A broad area of low pressure is located over the central Gulf of Mexico".
There were two other systems in development Wednesday as well. A hurricane hunter plane is scheduled to investigate the system Thursday.