Hurricane Dorian is a 105 mph Category 2 hurricane that isn’t content to stay that way for long. The National Hurricane Center is forecasting Dorian to become a Category 3 or greater “major” hurricane on Friday as it heads toward a potential landfall in Florida or elsewhere along the East Coast by Monday or Tuesday, potentially as a powerful Category 4 storm.
Since Thursday morning, one major forecast development is that the storm’s forward speed is now expected to slow to a crawl by Sunday. However, there’s been a noticeable southerly trend in the forecast track toward the end of the forecast period, which puts southeastern Florida at particular risk.
However, all of Florida remains within the so-called “cone of Uncertainty.”
On Thursday night, Dorian has continued its march northwestward (at 12 mph) and was centered about 295 miles east of the southeastern Bahamas.
The National Hurricane Center is predicting that Dorian is in a region that is extremely conducive to intensification, with very warm waters and favorable upper-level winds. This area is an atmospheric tinder box that could support rapid intensification.
“Unfortunately, I don’t see any large-scale factors that would prevent Dorian from becoming an extremely dangerous category 4 hurricane during the next few days,” wrote a forecaster at the Hurricane Center in a technical discussion posted online.
“Dorian is predicted to remain a dangerous hurricane throughout the remainder of the forecast period,” cautioned the National Hurricane Center in its Thursday night bulletin.
As Dorian approaches the Florida coast over the Labor Day weekend, the official Hurricane Center forecast predicts peak winds to reach 140 mph, a Category 4 storm with the potential to cause “catastrophic” damage.
“The risk of devastating hurricane-force winds along the Florida east coast and peninsula late this weekend and early next week continues to increase, although it is too soon to determine where the strongest winds will occur,” the Hurricane Center wrote.
In addition to the wind, heavy rains from the storm are expected to develop over portions of the Bahamas and Florida late this weekend into early next week. Storm surge flooding, which is the storm-driven rise in ocean water above normally dry land, is another major threat, particularly given unusually high astronomical tides this weekend known as “King Tides.”
If the storm stalls close enough to the coastline, it could produce damaging waves and storm surge flooding from Florida to South Carolina, illustrating the broad scope of the threat.
Florida Gov. Ron DeSantis (R) declared a state of emergency Wednesday afternoon “to ensure local governments and emergency management agencies have ample time, resources and flexibility to get prepared,” he posted on Twitter.
What we’re confident about
There’s not much holding Dorian back from quickly becoming a top-tier hurricane. Any regions it closely impacts would probably be subject to destructive winds over 100 mph, storm surge flooding and the threat of inland flooding from heavy rainfall.
We also know that Dorian will take a few days before it makes a potential turn toward land, giving forecasters time to refine the outlook and people time to prepare. As Dorian is a relatively small hurricane, subtle shifts in path — only on the order of 50 miles or less — could mean the difference between devastating winds and a more modest impact. Brian McNoldy, Capital Weather Gang’s tropical weather expert, tweeted that the National Hurricane Center’s average track error this far out is three times that — 150 miles. The stakes with this forecast are high, and the uncertainty beyond day 3 is still high.
We’re also confident that if the scenarios shown by some models, with a major hurricane hitting Florida moving from the east to west, do come to fruition, the storm surge would be maximized.
Another thing we’re quite confident about is that there will be a battle taking place between various weather systems that will help steer the storm, resulting first in a collapse of steering currents that will leave the storm a bit aimless for a time. Then Hurricane Dorian may slide southwest, crashing onto the coast of South Florida, or possibly even make a run for it off the east coast of the Sunshine State.
The unknowns
But will it reach land? That’s the looming question, and uncertainty remains unusually high. While it’s very likely that the mainland United States will see a hurricane landfall associated with Dorian, it’s not a certainty. There’s still considerable spread in model guidance regarding Dorian’s eventual track.
Group of simulations from American (blue) and European (red) computer models from Thursday afternoon for Hurricane Dorian. Each color strand represents a different model simulation with slightly altered input data. Note that the strands are clustered together where the forecast track is most confident but diverge where the course of the storm is less certain. The bold red line is the average of all of the European model simulations, while the bold blue one is the average of all the American model simulations. (StormVistaWxModels.com)
It boils down to the strength of the Bermuda High located to the north and east of Dorian. That blocking weather system serves as a guardrail, steering Dorian around its western flank. A weaker Bermuda High might allow Dorian to turn north before making landfall in Florida, bringing effects to Georgia and the Carolinas but potentially just fringing the coast. There are a number of weather models that indicate this potential.
[Hurricane Dorian is not your typical Florida tropical cyclone]
But a stronger high ― as remains more possible — would present a much more serious threat to Florida and/or the Carolinas.
The official National Hurricane Forecast predicts Dorian to reach Category 4 strength while approaching the eastern coast of Florida on Monday night into Tuesday. That is a slightly slower timing than was forecast Wednesday, allowing residents more time to prepare but also giving more time for a weather system over New England, plus the high-pressure area, to potentially lure the storm farther north or out to sea.
Some of the more recent model simulations suggest Dorian will slow or stall as it approaches Florida, hugging the coast or meandering just offshore over multiple high-tide cycles at starts to turn north. “One of the most concerning parts of the #Dorian track is how slow it gets near Florida,” tweeted Rick Knabb, hurricane expert at the Weather Channel. “Storm surge and wind will likely be life-threatening, but let’s also prepare for an inland flood disaster somewhere in southeastern U.S. That hazard has taken the most lives in recent years.”
The main messages
There is still considerable uncertainty with this storm track forecast.
We’re still not at the point where we can say where exactly Dorian will hit — if a U.S. landfall does occur at all. We’ll have a clearer picture Friday into Saturday as we trend closer to the actual event. Several models indicate Dorian may actually track across the Florida peninsula and reemerge into the Gulf of Mexico, then strengthen again. This would be a disturbing scenario and a model trend that warrants watching.
Anyone from South Florida through the Carolinas should be closely monitoring Dorian’s progress and preparing for a potentially destructive storm.
As the National Weather Service in Melbourne, Fla., wrote, “There is no better time than now to review your hurricane preparedness plan.” That also means fully stocking your hurricane kit, readying nonperishable foods, filling prescriptions for any essential medication, etc. It may also be a good point to call inland residents and chat about visiting them over the Labor Day weekend if you are forced or encouraged to evacuate; this is especially true for those along Florida’s Atlantic Coast, as well as the coastal Carolinas.
Hurricanes are both physically and emotionally taxing, particularly if you have young children. Amid potential power outages and inevitable fear, having distractions or activities to occupy them — such as board games, craft projects or books — is a smart move and adds a touch of levity if you find yourself in Dorian’s crosshairs riding out the storm. Consider swinging by your local supermarket Thursday or Friday to include these or more personal items in your storm kit.
Regardless of whether you stay, which will ultimately depend on the forecast, use this “calm before the storm” to prepare for all possible outcomes and ready yourself for whatever ends up happening.
Dorian in historical perspective
If Dorian makes landfall in Florida, it will 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 130 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.
