Tropical Storm Fiona watches for Puerto Rico, Virgin Islands

Tropical Storm Fiona grew in strength Thursday afternoon prompting tropical storm watches for Puerto Rico and the U.S. Virgin Islands, the National Hurricane Center said.

As of the NHC’s 5 p.m. advisory, Fiona was located about 425 miles east of the Leeward Islands with maximum sustained winds of 60 mph, up from 50 mph earlier Thursday. The system is moving west at 14 mph with tropical-storm-force winds extending out 140 miles.

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

A tropical storm watch is also in effect for the British Virgin Islands.

“A westward motion with some decrease in forward speed is expected through Saturday night, with a turn toward the west-northwest possible on Sunday,” said NHC senior hurricane specialist Robbie Berg. “On the forecast track, the center of Fiona is expected to move across the Leeward Islands Friday night and early Saturday, and move near the Virgin Islands and Puerto Rico late Saturday into Sunday.”

The forecast has the system strengthening, but just shy of hurricane status in the next five days.

On Wednesday night, Fiona became a tropical storm when satellite data showed Tropical Depression 7 had strengthened, maintaining maximum sustained winds greater than 39 mph. It is not yet known if the tropical storm would impact Florida or the mainland United States.

Most projected storm paths show Fiona making a hard bend northeast away from the Sunshine State. The latest five-day track has its cone of uncertainty over the Turks and Caicos and approaching the southern Bahamas by Tuesday with gusts of up to 85 mph.

“The main global models suggest that the cyclone could end up anywhere from eastern Cuba to well to the northeast of the Bahamas by the end of the forecast period,” Berg said. “For now, the official track forecast is nudged southward and westward from the previous forecast, accounting for the adjusted initial position and the overall trend in the track guidance.”

Earlier Thursday, forecasters had not been impressed with Fiona’s structure, calling it “sheared” and “asymmetric,” and suggesting the ragged form doesn’t yield itself to much strengthening in the near future. Hindering it further is a strong northwesterly wind shear expected to stymie the storm for the next few days, but it may not be enough to prevent any strengthening at all.

“Fiona’s current intensity is a testament to its resilience in the face of the shear it has experienced over the past 24 hours,” said Berg.

Despite environmental factors, Fiona has been able to retain its power.

However, conditions only get worse for Fiona as its core interacts with dry air and is potentially impacted by land interference while passing over portions of the Greater Antilles this weekend and early next week.

On Monday, Fiona could interact with the Hispaniola mountain range, which historically weakens tropical storm organization due to the mountainous terrain’s effect on the wind structure. However, predictions actually show Fiona’s winds growing in power to about 70 mph at around the same time it would be passing over Hispaniola. Global models suggest Fiona could even become a hurricane, according to Colorado State University’s two-week prediction of the tropics.

“While Fiona is not forecast to intensify much in the short-term, most global models intensify it to hurricane strength by next week,” CSU said.

The Caribbean islands are expected to have heavy rain through the weekend with Hispaniola receiving a maximum total of 12 inches. Showers on the Leeward Islands are expected to accumulate 4 to 6 inches of rain Friday night.

“This rainfall may produce isolated flash and urban flooding, along with isolated mudslides in areas of higher terrain,” Berg said.

Currently, hurricane season is in the middle of the most active time for tropical activity, between mid-August and mid-October.

Prior to the season, National Oceanic and Atmospheric Administration forecasters predicted 2022 to be yet another above-average season in storm production coming off the heels of two record-breaking seasons for named storms. The NOAA doubled down on its forecast at the start of August. However, the season has been off to a sluggish pace compared to past seasons.

Typically, the eighth named storm emerges by or before Sept. 9…