While lashing the Turks and Caicos on Monday night into Tuesday morning, Fiona became the first major hurricane, rated Category 3 or higher, of the 2022 Atlantic season. It already brought catastrophic flooding and mudslides to Puerto Rico while knocking out power across the island. It also delivered wind damage and excessive rains to the Dominican Republic.
While spotty downpours trailing the storm remained in Puerto Rico and the Dominican Republic on Tuesday, much of the rain has ended.
Now Bermuda is in the crosshairs of the system as it churns northward and picks up speed. The storm is forecast to make an ominously close pass at the island Thursday night before accelerating even further and heading toward Newfoundland and Labrador.
An approaching cold front will keep Fiona away from the U.S. East Coast, but the danger to the Lower 48 is actually growing — not from Fiona but from a new tropical disturbance lurking in its wake.
A clumping of downpours and thunderstorms several hundred miles east of the Windward Islands is poised to develop. The National Hurricane Center says it has a 70 percent chance to become a tropical depression or storm over the next several days as it enters the Caribbean from the Atlantic. Some long-range model simulations suggest it might become a concern for the Gulf of Mexico.
The environment looks unusually primed to support intensification into what may be a formidable storm system, but at more than seven days out, the inherently uncertain forecast renders it impossible to offer specifics — particularly considering that the storm has yet to develop. Still, for residents along the Gulf Coast, as well as Cuba and the Yucatán Peninsula, signs point to this being one to watch.
In the meantime, a new tropical depression has formed over the open North Atlantic. It will probably earn the name Gaston but should remain out at sea. It should become a named tropical storm in the next 24 hours before slipping northeast toward the Azores and eventually converting into a nontropical low this weekend.
As of 11 a.m. Tuesday, Fiona was located just 40 miles north-northwest of Grand Turk Island in the Turks and Caicos. The western eyewall, along the ring of destructive winds around the storm’s calm center, has been plowing through the island, buffeting Cockburn Town with wind gusts probably exceeding 100 mph. The storm strengthened overnight, becoming a Category 3.
Maximum winds within the eyewall are estimated at 115 mph. A “Hurricane Hunter” aircraft reconnaissance mission reported a circular eye about 30 miles wide. The flight also found that temperatures warmed about 10 degrees inside the eye, signifying an intensifying storm. That’s because the eye is characterized by sinking air. Air that subsides tends to be warm and dry. Typically, the hotter and drier the air in the eye is, the stronger the storm.
Where Fiona’s going
Fiona will withdraw to the north-northwest of the Turks and Caicos in the coming hours while potentially grazing the southeastern Bahamas, which are under a tropical storm warning. As the hurricane curves to the north and northeast Wednesday into Wednesday night, it may intensify into a Category 4.
Fiona is currently forecast to remain far enough west of Bermuda to spare the island direct eyewall impacts, but wind and rain will accompany outer rain bands and squalls that pivot northward feeding into the storm — probably Thursday night. A direct hit still cannot be ruled out, as it would require only a small deviation to the east of the current forecast.
Thereafter, Fiona could visit eastern Nova Scotia or western Newfoundland and Labrador as an unwelcome guest, potentially packing Category 1 winds, significant beach erosion and a storm surge as it rides up the Gulf of St. Lawrence. Heavy rainfall would be likely, too. This would be sometime from late Friday into Saturday.
By then, it may be undergoing extratropical transition, or morphing into a nontropical low. That would come from an influx of jet stream energy and the development of fronts as Fiona begins to eventually feed off baroclinicity — or the energy derived from clashing air temperatures rather than warm ocean waters.
A potential Caribbean and gulf concern
Fiona is not the only system to watch. The disturbance headed toward the Caribbean will be moving over an untapped reservoir replete with high ocean content, or fuel for tropical storm development, when it arrives later this week.
In addition to warm ocean temperatures to foster storm intensification, there will be little in the way of disruptive shear, or changing winds with height. Such shear can play a game of tug-of-war as a system strives to develop vertically, knocking it off kilter.
Moreover, there will be an upper-level high-pressure system working atop the system. That will help to enhance outflow, or exhaust from the fledgling tropical system. The more a storm “exhales” spent air aloft, the greater its ability to ingest warm, humid air in contact with the ocean surface from below. That encourages it to strengthen.
In fact, the storm should have dual outflow channels and be able to expel air to the north and south. That will further kindle strengthening, particularly since upper-level divergence, or the spreading of air, will act like a vacuum and enhance upward motion from below.
Steering currents could also open the door for a strengthening storm to strike land, but it’s too early to surmise if and where that would be a possibility.
This system, though not even formed, offers a litany of reasons to pay attention. Forecasters will be doing exactly that — and interests along the Gulf Coast probably should be monitoring it, as well.