Introduction to Hurricane Melissa
A late-season tropical wave in the eastern Caribbean is likely to become Tropical Storm or Hurricane Melissa this week, and forecasters say South Florida should be keeping an eye on the long-range tracking models.
The system, which as of Monday morning was located a few hundred miles south of Puerto Rico and moving westward, “currently lacks a closed circulation” because it is moving so fast, according to the National Hurricane Center. But that’s going to change in the next 24-48 hours as steering currents slow down and allow for rapid organization.
Forecast Models and Potential Threats
The so-called “spaghetti models,” which are computers that forecast the long-range track of a storm, show what will likely be Tropical Storm Melissa — or possibly even a hurricane — taking an eventual turn to the north, then northeast. Where that turn happens will determine how much of a threat Florida will be under.
If the storm turns in the central Caribbean, it will likely be a significant threat to Haiti, the Dominican Republic, or other islands — but keep Florida out of its direct path.
A later turn closer to the coast of Central America would put the southern half of Florida under threat. That scenario has the system slowing significantly, and remains as many as 10 days away. Things could change drastically before then, Fox Weather hurricane expert Bryan Norcross wrote on his blog, Hurricane Intel.
Computer models show a wide range of possible tracks for a tropical system in the Caribbean. Darker colors show a higher density of agreement of the forecast, while lighter blues show lower agreement. (polarwx.com)
Steering Forces and Storm Development
A steering force in the models is the subtropical jet stream, which has dipped into the Gulf. “(The jet stream) seems content on parking itself there for the foreseeable future,” wrote WPLG-TV hurricane specialist Michael Lowry on his Eye on the Tropics blog. “Strong upper-level winds associated with this subtropical jet will continue to act as a staunch barrier against would-be threats, tearing apart anything trying to get close to the U.S. coastline.”
As of Monday morning, the system is churning up a large area of showers and thunderstorms, which are expected to impact the Windward Islands in the southeastern Caribbean through Monday morning.
The system is predicted to further organize midweek in the central or southern Caribbean, moving west at about 20 to 25 mph.
“As it reaches the warm waters of the Caribbean early this week, low wind shear may allow it to quickly become a tropical storm,” said AccuWeather Lead Hurricane Expert Alex DaSilva. “Atmospheric conditions are primed for a storm to form in the Caribbean. The waters are exceptionally warm since the Caribbean has not been disturbed by a single tropical storm or hurricane so far this season. The longer this tropical wave remains over these unusually warm waters, the greater the potential for rapid intensification.”
Storm Intensification and Tracking
Computer models are split on how strong the storm will get. All show it becoming a tropical storm by Wednesday morning and most show a hurricane by late in the week. Some models predict it could even become a major hurricane — Category 3 or higher.
While most forecasting models show a Tropical Storm Melissa forming by Wednesday, some also show the storm strengthening into a hurricane by later in the week. (polarwx.com)
As of 8 a.m. Monday, the National Hurricane Center has given it a 50% chance of developing in the next 48 hours and a 80% chance of developing in the next seven days, a spike in odds from 48 hours prior.
A tropical wave, located in the eastern Caribbean on Monday, could develop this week into a tropical depression or tropical storm, forecasters say. (National Hurricane Center/courtesy)
Conclusion
The storm would have to get to Jamaica or Mexico’s Yucatán Peninsula to be of concern to Florida as we see it now, according to AccuWeather Lead Hurricane Expert Alex DaSilva.
“The track of the disturbance is unusually far south, especially for October,” Norcross wrote. “One of the open questions about the forecast is whether the system will track so close to the South American coast that it won’t be able to organize and intensify.”
Four hurricanes have formed so far in the Atlantic season, and none has hit the U.S. Of the 12 named Atlantic storms so far, only Tropical Storm Chantal has made a U.S. landfall.
Hurricane season runs through Nov. 30.
FAQs
Q: What is the current status of the tropical wave in the eastern Caribbean?
A: The system is currently located a few hundred miles south of Puerto Rico and moving westward, with a 50% chance of developing in the next 48 hours and a 80% chance of developing in the next seven days.
Q: What are the potential threats from the storm?
A: If the storm turns in the central Caribbean, it will likely be a significant threat to Haiti, the Dominican Republic, or other islands. A later turn closer to the coast of Central America would put the southern half of Florida under threat.
Q: How strong is the storm expected to get?
A: Computer models are split on how strong the storm will get, with all showing it becoming a tropical storm by Wednesday morning and most showing a hurricane by late in the week. Some models predict it could even become a major hurricane — Category 3 or higher.
Q: What is the forecast for the storm’s track?
A: The long-range computer models show a wide margin of error in the storm’s future tracks, with a wide range of possible tracks for the tropical system in the Caribbean.
