Hurricane Dorian gained Category 4 intensity faster than expected, illustrating the complexities involved in anticipating periods of rapid intensification. As of 11 p.m., the storm was positioned about 545 miles east of West Palm Beach and heading west-northwest at 10 mph. It’s spinning above warm waters, which act as fuel for the storm, all along its track.
In its 11 p.m. advisory, the Hurricane Center wrote that “... all indications are that Dorian will remain an extremely powerful hurricane for the next several days." The northwest Bahamas are expected to take a direct hit from the storm in its most fearsome state on Saturday night and Sunday, with the potential for “A prolonged period of life-threatening storm surge and devastating hurricane-force winds,” the NHC stated.
By the time Dorian nears Florida on Labor Day into Tuesday, it is still forecast to be a Category 4 storm, given warm waters and few obstacles in its path, such as wind shear, that might weaken it some.
However, Dorian’s exact path — which for days has proved difficult to pin down — remains elusive. And it has major implications for how severely Florida is affected as well as other states in the Southeast.
By the time Dorian reaches the northwestern Bahamas on Sunday and Monday, the Hurricane Center calls for steering currents to “collapse,” making for a “highly uncertain” track forecast.
A “small deviation in the track could bring the core of the powerful hurricane well inland over Florida, keep it near the coast, or offshore,” it wrote in its 5 p.m. Friday bulletin. Some computer model guidance shows that Hurricane Dorian could make an earlier turn to the north to parallel the Florida coastline, which could avoid a landfall of the storm’s center. However, unless Dorian follows a track well offshore of Florida, the storm has the potential to unleash damaging winds, flooding rains and a life-threatening storm surge, which is the storm-driven rise in water above normally dry land at the coast.
“Although the official forecast track has been nudged northeastward to near the east coast of Florida the risk of significant impacts over much of the Florida peninsula remains high,” the Hurricane Center stated in a forecast discussion posted online.
The storm surge will be exacerbated by naturally occurring astronomical high tides, which are some of the highest of the year this weekend into early next week. The surge threat could extend northward to Georgia and the Carolinas by Tuesday and Wednesday.
Hurricane Dorian is forecast to move slowly as it approaches Florida and makes a north turn, which could bring a prolonged period of high winds and battering waves onto the state’s highly populated eastern coastline. The Hurricane Center warns that parts of Florida could see “a prolonged period of storm surge, high winds, and heavy rainfall” as Dorian could take more than two days to spread its wrath ashore and then crawl up the peninsula.
The slow-motion storm would not only prolong the hours of punishing hurricane-force winds, but also expose the coast to numerous high-tide cycles, increasing the magnitude and duration of coastal flooding, and weakening coastal infrastructure.
Hurricane conditions could endure an entire day or longer in some locations if the eyewall, where the storm’s most intense winds are located, comes ashore.
Depending on the storm’s forward speed, rainfall amounts could become extreme, with totals easily eclipsing 10 inches over large areas and potentially exceeding two feet in spots, according to some model projections. Such amounts would lead to major freshwater flooding, which has become the biggest killer in hurricanes in recent years.
Inland areas of Florida, in addition to the coast, face potentially damaging winds and tremendous rainfall.
If Dorian strikes Florida’s east coast as a Category 4, it would be the strongest to make landfall there since Hurricane Andrew in 1992 but will be moving at a much slower pace.
Hurricane warnings are up for the northwestern Bahamas, including Grand Bahama Island and the Abacos, where Dorian will arrive sometime Sunday into Sunday night. By then, Dorian will still be a Category 4 storm, and confidence of severe impacts there is higher than in Florida. Tropical-storm-force winds could reach the eastern Bahamas by early Saturday and Florida’s east coast by Sunday night.
The Hurricane Center warns of a “life-threatening” storm surge raising waters by as much as 10 to 15 feet above normal tide levels in areas of onshore winds in the northwestern Bahamas.
Dorian’s punishing wind and water could menace parts of Florida through Wednesday or even into Thursday, and affect Georgia and the Carolinas late Tuesday through the end of the week.
Storm track projections and the implications
Assuming Dorian makes a close approach to Florida or comes inland, it will be an extremely dangerous and potentially life-threatening storm. There is a credible chance that the worst of the storm curves out to sea before striking Florida or the Southeast United States. However, even in that scenario, high winds, heavy rains, and dangerous storm surge conditions would threaten coastal areas in particular.
The exact path Dorian takes depends on two weather systems competing to steer the storm in different directions: a blocking high-pressure zone to its north and east, and a dip in the jet stream, or trough, to its northwest. The high acts as a guardrail, its clockwise winds shunting Dorian west while the jet stream dip will try to “scoop” Dorian north.
Depending on when Dorian nears Florida, Dorian could either be shunted farther west by the high-pressure cell and trek inland, or curve to the north, churning up the immediate east coast of Florida or even remaining centered just offshore. If Dorian is to make landfall, the most likely location would be somewhere between Fort Lauderdale and the Space Coast.
However, there are other scenarios in play, including a later turn that would take the center of the storm inland over central Florida before turning north, potentially exposing the entire width of the state to hurricane-force winds.
Which scenario will happen? We just don’t know. In fact, we probably won’t have a good idea of that until late Saturday or Sunday. We are confident that Dorian will be a severe hurricane. There’s ample fuel to sustain impressive strengthening, and rapid intensification (an increase of winds of 35 mph in 24 hours) has already occurred. It’s not out of the question that the storm achieves Category 5 status, though that’s not explicitly called for in the Hurricane Center’s forecast.
What we are not confident about, at least not yet, is the specific track near or over Florida.
Subtle shifts in track will have enormous implications on the conditions experienced locally. Dorian is a compact but growing storm, so small differences in track could make a world of difference in terms of the biggest threats particular regions will face.
Destructive winds of 130 mph or more will accompany the eyewall, which is the most intense zone of winds surrounding the storm’s calm center, if, and where, it makes landfall potentially in southeast or east central Florida. A very dangerous storm surge is possible to the north of the storm’s center, bringing the potential to inundate coastal communities.
“Regardless of the exact track of Dorian, heavy rains are expected,” wrote the Hurricane Center.
Toward the middle of next week, it’s possible that Dorian’s remnants shuffle up the southeast coast, bringing heavy rain and strong winds to coastal Georgia and the Carolinas. Dorian couldn’t come at a worse time, with the high astronomical king tides tipping the scales toward a higher-end coastal flood event. Coastal flood alerts were posted Friday morning due to the tides alone.
Scenes from the path of Hurricane Dorian
In coastal Florida, Saturday and the first part of Sunday is the key window to prepare. Further north in coastal Georgia and South Carolina, there will be another day to get ready for the storm’s impacts.
Your preparations should begin the same way regardless of where in the “cone” you live, or where Dorian may go. Assemble your hurricane kit. Identify friends, relatives or any place of refuge farther inland you can relocate to if an evacuation order is given. Stock up on nonperishable foods for nourishment, and snag at least seven days’ worth of water. In addition, make plans to care for any elderly relatives who may be in need. You’ll also want to fill any prescriptions for medication.
“Residents should have their hurricane plan in place, know if they are in a hurricane evacuation zone, and listen to advice given by local emergency officials,” the Hurricane Center said.
Dorian in historical perspective
If Dorian makes landfall in Florida, it would be the fourth hurricane to do so since 2016, following Hermine (2016), Irma (2017) and Michael (2018).
“Assuming #HurricaneDorian makes landfall in Florida, this will be the 4th consecutive year with a Florida #hurricane landfall — the most consecutive years with a Florida landfall since they were hit by hurricanes in a whopping 7 consecutive years from 1944-1950,” tweeted Philip Klotzbach, a hurricane researcher affiliated with Colorado State University.
Klotzbach added that if Dorian makes landfall in Florida as a Category 4 with 140 mph sustained winds, as projected, it would be the strongest to hit Florida’s eastern coast since Andrew in 1992, which had winds of 165 mph. Only eight Category 4 or 5 hurricanes have made landfall in Florida since 1900.
Klotzbach also noted on Twitter: “#HurricaneDorian is forecast to make landfall in FL as a Category 4. It would be 3rd year in a row w/ Cat. 4+ FL hurricane landfall [Irma in 2017 and Michael in 2018]. FL has had Cat. 4 hurricane landfalls in 3+ consecutive years once on record (since 1851). Cat. 4 #hurricanes made landfall each year from 1947-50.”