Month: September 2018

At 500 AM AST (0900 UTC), the centre of Hurricane Florence was located near latitude 24.9 North, longitude 58.9 West. Florence is moving toward the west-northwest near 9 mph (15 km/h). A west-northwestward motion with an increase in forward speed is expected during the next couple of days.  A turn toward the northwest is forecast to occur Wednesday night or Thursday. On the forecast track, the centre of Florence will move over the southwestern Atlantic Ocean between Bermuda and the Bahamas Tuesday and Wednesday, and approach the southeastern coast of the United States on Thursday.

Satellite imagery indicates that the maximum sustained winds have increased to near 105 mph (165 km/h) with higher gusts. Rapid

strengthening is forecast, and Florence is forecast to become a major hurricane this morning, 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 centre and tropical-storm-force winds extend outward up to 125 miles (205 km).

At 500 AM AST (0900 UTC), the centre of Hurricane Helene was located near latitude 14.3 North, longitude 28.9 West. Helene is moving

toward the west-northwest near 17 mph (28 km/h) and this motion is expected to continue for another couple of days.  A turn to the northwest is forecast to occur on Wednesday.

Maximum sustained winds are near 85 mph (140 km/h) with higher gusts.  Helene’s expected to resume strengthening today.  Afterward,

weakening is forecast to commence Wednesday morning.

Hurricane-force winds extend outward up to 25 miles (35 km) from the centre and tropical-storm-force winds extend outward up to 90 miles

(150 km).

At 500 AM AST (0900 UTC), the centre of Hurricane Isaac was located near latitude 14.7 North, longitude 42.7 West. Isaac is moving

toward the west near 13 mph (20 km/h).  A westward motion with a slight increase in forward speed is forecast through the end of the

week.  On the forecast track, Isaac is forecast to move across the Lesser Antilles and into the eastern Caribbean Sea on Thursday.

Maximum sustained winds remain near 75 mph (120 km/h) with higher gusts.  Additional strengthening is expected over the next day or

two.  Weakening is forecast to begin by the middle of the week as Isaac approaches the Lesser Antilles.

Isaac is a small hurricane.  Hurricane-force winds extend outward up to 10 miles (20 km) from the centre and tropical-storm-force winds

extend outward up to 45 miles (75 km).

At 500 AM AST (0900 UTC), the centre of Tropical Storm Helene was located near latitude 13.2 North, longitude 24.0 West. Helene is moving toward the west near 14 mph (22 km/h), and this motion is expected to continue through today.  A turn toward the west-northwest is forecast to occur by Monday.

Maximum sustained winds have increased to near 65 mph (100 km/h) with higher gusts.  Additional strengthening is forecast during the next couple of days, and Helene is expected to become a hurricane later today.

Tropical-storm-force winds extend outward up to 80 miles (130 km) from the centre.

At 500 AM AST (0900 UTC), the centre of Tropical Storm Isaac was located near latitude 14.5 North, longitude 38.1 West. Isaac is moving toward the west near 9 mph (15 km/h). A westward motion with an increase in forward speed is expected during the next few days.

Maximum sustained winds remain near 50 mph (85 km/h) with higher gusts.  Strengthening is forecast during the next few days, and Isaac is expected to become a hurricane by Monday.

Tropical-storm-force winds extend outward up to 60 miles (95 km) from the centre.

At 500 AM AST (0900 UTC), the centre of Hurricane Florence was located near latitude 24.1 North, longitude 47.9 West.  Florence is moving toward the northwest near 12 mph (19 km/h).  A turn toward the west-northwest with a decrease in forward speed is expected

later today, followed by a turn toward the west by the weekend.

Maximum sustained winds have decreased to near 115 mph (185 km/h) with higher gusts.  Florence is a category 3 hurricane on the

Saffir-Simpson Hurricane Wind Scale.  Some additional weakening is forecast today, but Florence is expected to remain a strong hurricane for the next several days.

Hurricane-force winds extend outward up to 15 miles (30 km) from the centre and tropical-storm-force winds extend outward up to 90 miles

(150 km).

1. A broad area of low pressure is centred a few miles southwest of the Cabo Verde Islands.  Shower and thunderstorm activity associated

with this low has changed little in organisation over the past few hours and recent satellite data indicate that a well-defined centre

has not yet formed.  However, environmental conditions still appear to be conducive for development and a tropical depression is expected to form within the next few days while the system moves toward the west or west-northwest across the tropical Atlantic Ocean.

* Formation chance through 48 hours…high…70 percent.

* Formation chance through 5 days…high…90 percent.

2. A tropical wave is forecast to move off the west coast of Africa on Friday.  Some development of this system is anticipated after that time, and a tropical depression could form over the weekend or early next week while the wave moves westward over the far eastern tropical Atlantic Ocean.

* Formation chance through 48 hours…low…near 0 percent.

* Formation chance through 5 days…medium…50 percent.