|Above: A view of the "stadium effect" from the intense thunderstorms lining the eyewall of Hurricane Dorian as photographed from an Air Force Hurricane Hunter aircraft on September 1, 2019. Image credit: Garrett Black.|
Category 5 Hurricane Dorian, in no hurry to clear the Northwest Bahamas, gave the Abaco Islands a prolonged, punishing blow on Sunday. Grand Bahama Island is in line for similar treatment on Monday as Dorian slows to a crawl. The hurricane is still projected to arc dangerously close to the Southeast U.S. coast as this week unfolds.
A hurricane warning was issued Sunday afternoon from Jupiter Inlet, Florida, north to the Volusia/Brevard county line, with a hurricane watch in effect southward to Jupiter Beach and northward along the entire Volusia County coast. Hurricane, tropical storm, and storm surge warnings are normally issued no more than 36 hours in advance of expected conditions, so we can expect these to be extended further up the Southeast coast over the coming days, with many revisions to come.
Dorian’s first landfall on Great Abaco Island was at Elbow Cay and its second at Marsh Harbour, both with top winds at 185 mph. Catastrophic damage was evident from Great Abaco Island in a smattering of news reports and social-media posts that emerged as the eye passed over. Nothing more had been heard from the island as of Sunday night. See the frequently updated weather.com article for the latest on Dorian’s impacts.
"It's devastating," Joy Jibrilu, director general of the Bahamas' Ministry of Tourism and Aviation, told the Associated Press midway through the storm. "There has been huge damage to property and infrastructure. Luckily, no loss of life reported."
Dorian is tied with the Labor Day Hurricane of 1935 in the Florida Keys as the most powerful landfalling Atlantic hurricane (by wind speed) on record.
Hurricane history of The Bahamas
The only other Category 5 hurricane on record to make landfall in The Bahamas was Hurricane Andrew, which hit Eleuthera Island on August 23, 1992 with sustained winds of 160 mph.
Prior to Dorian, the most recent hurricane to affect The Bahamas was Hurricane Irma, which made landfall on the Little Inagua Island on September 8, 2017 as a top-end Category 4 storm with 155 mph winds. Irma’s eye also passed over Duncan Town, the major settlement of the Ragged Islands chain. Damage from Irma was estimated at $135 million, but no one was killed.
Hurricane Matthew of 2016 passed from south to north through the middle of The Bahamas, and its strong east eyewall moved over Freeport on Grand Bahama Island. Matthew caused $640 million (2019 dollars) in damage in The Bahamas—their second most expensive hurricane in history. According to EM-DAT, the most expensive hurricane in Bahamian history was Category 4 Hurricane Frances of 2004, with damages estimated at $1.3 billion (2019 dollars)—a crippling 18% of their $7.1 billion GDP at the time.
Hurricane Joaquin made landfall as a major hurricane on several islands of the Bahamas on October 1 and 2, 2015: Samana Cay, Rum Cay, and San Salvador. In addition, Joaquin’s eyewall moved over Crooked Island, Long Cay, and Long Island. Joaquin was the strongest October hurricane known to have affected the Bahamas since 1866, peaking as a high-end Category 4 storm with 155 mph winds on October 3. Joaquin killed 33 people in The Bahamas, making it their deadliest natural disaster in history. Damage was estimated at $97 million (2019 dollars).
Hurricane Sandy of 2012 passed through the central Bahamas as a Category 2 storm with winds of up to 105 mph. Sandy caused two deaths and damage estimated at $703 million, equivalent to 9% of the nation's GDP. The most severe damage was on Cat Island and Exuma, due to wind and storm surge.
What next for Dorian?
Dorian may have peaked in strength on Sunday. Reconnaissance flight data from Sunday night showed that the central pressure had leveled off between 910 and 915 millibars. An eyewall replacement cycle (ERC) also appears to be under way (see Figure 2). Between this ERC and the effects of upwelled cooler water as Dorian slows down, Dorian’s peak wind speeds may drop into the Category 4 or lower Category 5 range by Monday. Dorian's wind field will likely expand, though, as a result of the ERC.
|Figure 2. Composite radar image of Dorian at 5:05 pm EDT September 1, 2019. The inner eyewall was beginning to be ringed by a larger-diameter outer eyewall, in a process called an eyewall replacement cycle (ERC). An outer eyewall was also becoming evident on microwave imagery. Image credit: bahamasweather.org.bs.|
Dorian’s forward speed, down from 7 mph at 11 am EDT Sunday to around 5 mph as of 8 pm, will likely drop to the 2-3 mph range by Monday as the hurricane passes along or very near Grand Bahama Island (population 51,000). This will lead to a protracted pounding of the island. Storm surge is predicted to reach the 18 – 23 foot range at onshore locations, which will vary over time as the hurricane crawls west. Most locations on Grand Bahama Island are likely to experience at least some period of time within the fierce winds of the eyewall, and phenomenal rainfall amounts topping 30” can be expected. Because of Dorian’s intense strength and slow forward motion, there will be relatively little difference in eyewall wind strength on the left- versus right-hand sides of the storm.
The bulk of computer model guidance continues to take Dorian slowly west before a sharp right turn on Tuesday that will bring it near the Southeast U.S. coast from late Tuesday until Friday. However, about half of the 12Z UKMET ensemble have a less-sharp right turn that takes Dorian inland and north-northwest up the Florida peninsula. The 12Z GFS ensemble had no members bringing Dorian into Florida, while only a small minority of European ensemble members showed a Florida landfall. The high-resolution HWRF model—the other one of the four top-performing track models in the 2018 hurricane season—continues to depict a landfall along Florida's Space Coast.
The question remains how far west Dorian will inch before it makes its crucial turn. Historical analogs are not comforting in this regard, as several hurricanes have cut further west-southwest than expected in this part of the world—including Irma in 2017, which moved left of its two-day forecast track to strike north central Cuba, and Katrina in 2005, which angled west-southwest into the Florida Everglades contrary to the westward track predicted just a day earlier. Both of these shifts were within the forecast cone, which for Dorian extends as far south as Palm Beach County.
We can take heart in the fact that hurricane modeling continues to improve—yet, as always, we must remember that hurricanes can strike anywhere within the forecast cone, and in fact end up outside the cone about one-third of the time. If you are in the cone, please take the hurricane precautions recommended by your local agencies!
Incredible to think there is a category 5 hurricane less than 200 miles east of me, and the threat from #Dorian is judged to be low enough that there’s no warning in place for #Miami. We live in amazing scientific times! pic.twitter.com/VgX3m9kSZQ— Eric Blake (@EricBlake12) September 1, 2019
A major, prolonged storm surge threat likely for the Southeast coast
Regardless of how close it gets to the Southeast U.S. coast, Dorian will push vast amounts of water against the shore for days to come. The NHC forecast keeps Dorian on an arcing path less than 100 miles offshore, from the central Florida coast on Tuesday to just southeast of Cape Hatteras on Friday. For comparison, 2016’s Hurricane Matthew—which carried out a similar loop a bit closer to shore—took less than half that long to cover the same general territory, as explained in this comparison article.
Matthew led to record storm surge at several locations in Florida and Georgia, and it would not be a surprise at all to see Dorian produce similar results at some locations by later this week.
We’ll have our next Dorian update by midday Monday.
Jeff Masters co-wrote this post.