Tropical Storm Fiona pushes west, NHC tracks two more systems

The Leeward Islands are bracing for heavy rain as Tropical Storm Fiona is expected to reach the Caribbean island chain Friday afternoon and evening. Meanwhile, the National Hurricane Center tracks two other tropical systems in the Atlantic.

As of the NHC’s 8 a.m. advisory, Fiona was 175 miles east of Guadeloupe with maximum winds of 50 mph on Thursday. The system is moving west at 15 miles per hour with tropical storm-force winds extending up to 125 miles.

Tropical storm warnings, which mean a threat within 36 hours, were in effect for the Caribbean islands of Antigua and Barbuda, Saint Kitts and Nevis, Montserrat, Anguilla, Saba, Saint Eustatius, Saint Martin, Guadeloupe, Saint Barthelemy, and Saint Martin

There is also a Tropical Storm Watch in effect in the British Virgin Islands.

Following the Fiona track, a tropical wave was detected on Thursday midway between the west coast of Africa and the Lesser Antilles. The weather system is producing disorganized showers and is expected to develop slowly late this weekend and early next week as it heads north over the mid-Atlantic. NHC gives it 20% of the composition over the five days.

Also, the NHC is now monitoring a frontal depression over the western Atlantic a few hundred miles west and northwest of Bermuda, which appeared Friday morning. The depression is expected to move eastward at 10 to 15 mph with producing unstructured showers and thunderstorms. The system is expected to remain disorganized due to upper level winds preventing it from developing into a tropical cyclone, the National Hurricane Committee said.

The recent emergence of the two systems coincides with Colorado State University releasing its tropical forecast for the next two weeks, saying the tropics could get busier with a 50% chance of above-average activity. CSU also gave a 40% chance of normal activity and a 10% chance of below-average activity.

On Wednesday night, Fiona became a tropical storm when satellite data showed Tropical Depression 7 had strengthened, maintaining maximum sustained winds of over 39 miles per hour. It is not yet known whether the tropical storm will affect Florida or the mainland United States.

Most forecast storm tracks show Fiona making an intense bend northeast away from the Sunshine State. The final five-day track contains a cone of uncertainty over the Turks and Caicos Islands and is approaching the southern Bahamas by Tuesday with gusts of up to 85 mph.

Fiona is still on track to bring heavy rain to the Leeward Islands tonight. After that, the storm is expected near the Virgin Islands and Puerto Rico on Saturday and Sunday. At this point, Fiona’s course turns northwest, potentially bringing it to Hispaniola as early as Monday where it can interact with the Hispaniola mountain range. Historically, mountainous terrain has been known to weaken the regulation of tropical storms and rupture wind structures.

“However, there are some indications that environmental conditions could become more favorable for a strengthening of storm strength in the eastern Caribbean this weekend,” said NHC specialist Brad Reinhart.

Storm forecasts show Fiona’s winds getting stronger to about 70 miles per hour around the same time they will finish passing over Hispaniola.

Global models suggest Fiona could become a hurricane, according to CSU’s two-week forecast for the tropics.

As for the immediate effect, heavy rain is expected on the Caribbean islands over the weekend, with Hispaniola receiving a total of 12 inches maximum. Rainfall on the Leeward Islands is expected to accumulate 4 to 6 inches of rain this evening.

“This rainfall may produce major flood effects including flash floods in urban areas, as well as mudslides in higher terrain areas,” Reinhart said.

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