Florida has had favorable tropical luck over the past few years.
Although climatology indicates that a hurricane should be expected in approximately 40% of the seasons, there has been no direct strike in the state since Michael’s doomsday hay in the Panhandle, give or take the Sally’s Eastern Eyewall of 2020 in Pensacola.
Consider the three major hurricanes that battered Louisiana in this era, and Florida’s recent punishment was truly light.
Unfortunately, that hot streak may well come to an end next week, with Florida facing its most serious threat since Dorian three years ago.
What we know: Will a hurricane hit Florida? What we know about Tropical Depression 9
Where is the storm going? : Tropical Depression Nine could hit Florida’s west coast as a major hurricane
Be ready : Here’s Your One-Stop Storm Preparedness Guide
And while the state becomes the likely target of a potential hurricane, there remains significant uncertainty about which part of Florida will bear the brunt of it.
What we know about Tropical Depression Nine: The African wave grabs Hermine’s name, but Ian is on deck
Tropical Depression Nine developed early Friday morning in the eastern central Caribbean and, as of the 11 a.m. advisory from the NHC, winds were blowing at around 35 mph. The low is moving slightly north of west at around 15 mph, and a general westerly track is likely through Saturday.
The wind shear is moving the low’s deep convection west of the center of circulation, which is expected to continue to gradually strengthen over the next couple of days. Still, TD 9 can become a tropical storm at any time.
(Side note: Since Tropical Depression 10 in the far eastern Atlantic has caught the name Hermine, Tropical Depression 9 will not be the second consecutive Hurricane Hermine in the Gulf, avoiding a ridiculous scenario of 2 Hermines, 2 furious. The next name on the list is Ian.)
Ermine the following: “It’s very early,” but could a second hurricane Hermine enter the Gulf of Mexico?
Now Sunday is when things start to get serious – at a possible Category 3 level
TD 9 will enter a western Caribbean environment in which upper flow is excellent, upper humidity is abundant, and vertical wind shear is low. In addition to this, the heat content of the waters of the northwest Caribbean is the highest in the entire Atlantic basin.
These factors are a perfect recipe for rapid intensification, defined as sustained winds that jump 30 knots or more in 24 hours.
The NHC intensity forecast explicitly calls for a rapid intensification from Sunday into Monday, and TD 9 will likely be in favorable conditions for continued strengthening through Tuesday.
The official forecast is that the storm will reach Category 3 strength by early Wednesday. This is a realistic base case, and I caution that even faster strengthening is certainly possible between Sunday and Tuesday.
It is exceptionally difficult to predict the degree of reinforcement that will occur during a rapid escalation cycle. History shows that major hurricanes can assemble at breakneck speed when the necessary ingredients are in place in the western Caribbean and southern Gulf.
All forecasts suggest TD 9’s track will gradually curve more northwestward on Sunday and Monday in response to a deep trough on the east coast, placing the storm on a track in the general direction of western Cuba d here late Monday. Subtle differences in guiding wind patterns will determine how far west TD 9 travels before a more northerly move occurs on Tuesday. The most likely track will carry the storm into the eastern Gulf of Mexico, although a more easterly track into the Florida Strait remains a possibility.
Hurricane Track and Pattern Mixer: Bookmark this page for the latest path and computer model runs
Uncertainty abounds: But South Florida residents should prepare now for a possible Hurricane Charley scenario
Forecasts are uncertain beyond Tuesday.
As of midday Friday, the official NHC track takes the storm near Fort Myers Wednesday morning as a major hurricane. This trajectory is very similar to that traced by Category 4 Hurricane Charley in August 2004, a phrase that is sure to have everyone in Southwest and Central Florida on their toes.
That scenario, or one in which the north and northeast turn unfolds even faster and puts the Keys and South Florida in the crosshairs on Tuesday, is probably the most dangerous scenario on the table.
The combination of a short lead time, high population density and the likely continuation of favorable strengthening conditions through early Wednesday means that residents of the southern half of the Florida peninsula should begin to prepare now for a possible major hurricane.
Panhandle is far from clear at this point
TD 9 could also swing further west towards the Yucatan Channel before heading north and then north-northeast over the eastern Gulf. This scenario would increase eventual risk for the Panhandle, Big Bend and West Central Florida, and today’s patterns are moving back west after a large eastward jump yesterday.
While more time over the Gulf seems like bad business, it could be offset by increased shear and dry air intrusion into the storm beyond Wednesday.
A further complication is that the eastern US trough will begin to pull away midway through next week, causing the eastern gulf to weaken in direction currents in 5-6 days and a period of movement slower or erratic that could ensue.
INTERACTIVE TOUR: Follow the arc of ruins from Hurricane Michael that devastated our communities
Ultimately, if the TD 9 doesn’t sprint through South Florida or East Central Florida on Tuesday or Wednesday, which is very possible, what could happen after that is unclear.
It is not possible to project a touchdown point with this type of predicted track, as the narrow angle of approach between the storm’s motion and the orientation of the Florida Gulf Coast means that small track deviations can have huge implications.
During Hurricane Charley, a subtle change in course just before landfall brought the fierce core of the storm into the Fort Myers area, rather than Tampa Bay. Do not focus on a point of forecast: for now, no one is off the hook in Florida.
Preparing for storms is essential
There are a lot of new residents in Florida since the last serious hurricane threat, which I can tell because some of you are still using your turn signals.
At this point, know that this threat deserves active preparation. In South Florida, you should implement your hurricane plans, including preparing to evacuate if an order is issued by your local authorities.
In North Florida, prepare your hurricane plan and kit and continue to monitor the situation. Let’s hope Florida’s luck doesn’t turn up this week, but if it does, preparation is key.
Keep looking at the sky.
Dr. Ryan Truchelut is chief meteorologist at WeatherTiger, a Tallahassee start-up providing forensic weather services and expert witness consultation, as well as agricultural and hurricane forecast subscriptions. Contact us at firstname.lastname@example.org and visit weathertiger.com for an enhanced, real-time version of our seasonal outlook.
Never miss a story: Subscribe to the Tallahassee Democrat using the link at the top of the page.
This article originally appeared on Tallahassee Democrat: Florida hurricane forecast could be the state’s biggest threat in years