A tropical disturbance located in the eastern Atlantic is producing disorganized showers and thunderstorms, and forecasters at the National Hurricane Center say a tropical depression is likely to form later this week or over the weekend as it moves across the Atlantic.
The NHC on Tuesday said environmental conditions will be favorable for gradual development, giving the system a 30% chance of formation within 48 hours and a 70% chance over the next seven days.
“A tropical wave is located over the far eastern tropical Atlantic southwest of the Cabo Verde islands and continues to produce disorganized showers and thunderstorms,” according to an update from the NHC on Tuesday evening. “Environmental conditions remain conducive for gradual development of this system during the next several days, and a tropical depression is likely to form late this week or this weekend.”
The NHC defines a tropical depression as “a tropical cyclone with maximum sustained winds of 38 mph or less.”
“This system is expected to move westward to west-northwestward at around 15 mph across the eastern and central tropical Atlantic into early next week,” the NHC added.
Are Impacts Possible Across the Caribbean?
The Source contacted Alex DaSilva, AccuWeather’s lead hurricane expert, to learn more about this tropical wave and if the USVI and Puerto Rico could experience any possible impacts in the coming days as it moves across the Main Development Region between the west coast of Africa and the Caribbean. If the disturbance intensifies into a tropical storm, with maximum sustained winds of at least 39 mph, it would be named Gabrielle, the seventh-named cyclone of this year’s Atlantic hurricane season.
“AccuWeather has been watching this tropical wave for days, and we have been concerned that it could become our next named storm in the Atlantic,” DaSilva said.
DaSilva went on to say that, while there is still plenty of time to learn where the storm may travel, computer forecast models have indicated the disturbance may pass near the Caribbean islands.
“Forecast trends have been moving a little more west with this wave over the last day or so. As a result, folks in the northeastern Caribbean need to be watching this tropical wave very closely,” DaSilva warned.
DaSilva said that in the short term, the disturbance will encounter dry air and wind shear. However, conditions will become more favorable during the week as the storm moves west to west-northwest.
“The wave is moving through an area of dry air right now which should limit short-term development,” DaSilva explained. “The wind shear is also forecast to decrease as it moves west. The storm is being pushed west by the Bermuda High. If the tropical wave ends up strengthening faster, it will have a tendency to pull farther north and that could allow it to move north of the islands. If it stays weaker, then it would likely move more west toward the islands. If there will be any rain and wind impacts, it looks like they would occur around the middle of next week,” DaSilva added.
A Potentially Busy September in the Tropics
The Atlantic hurricane season reaches its climatological peak around Sept. 10, and DaSilva stressed that tropical activity could become very busy soon.
“As we move through September, wind shear and dry air are expected to decrease across the Main Development Region. This can allow the ‘tropical wave train’ to become very active during the middle of the month as more waves move off the west coast of Africa,” DaSilva stated. “We are concerned about a rapid uptick in development toward the middle of September,” he said.
Sea surface temperatures remain very warm, and DaSilva noted that last month, Hurricane Erin temporarily cooled the waters through upwelling, which brought deeper, cooler water to the surface. The temperature of the waters in Erin’s wake has already begun to increase.
“As far as the upwelling from Hurricane Erin goes, water temperatures have started to rebound off the East Coast,” DaSilva said. “They are still warm enough to support a hurricane, however it will take another week or so to get back to near where they were before Erin moved through.”
NOAA Global Tropics Hazards Outlook
According to a Global Tropics Hazards Outlook released Tuesday, there will be an elevated chance of cyclonic development across the Atlantic basin. The forecast tool, which is issued weekly by the National Oceanic and Atmospheric Administration’s Climate Prediction Center, provides insight into potential activity across tropical basins up to three weeks in advance.
In its latest update, NOAA said that portions of the Atlantic basin may experience a 20-40% chance of cyclonic development during the “Week Two” outlook period, which runs from Sept. 10 until Sept. 16. A 40-60% chance of tropical cyclogenesis is forecast across the Main Development Region in the “Week Three” outlook, running from Sept. 17 through 23.
Areas across the western Caribbean Sea and the Gulf are also likely to see an increased chance of development.
Additionally, the Eastern Pacific basin, which continues to remain active, is also expected to experience an elevated risk for cyclonic development in the coming weeks.
El Niño Southern Oscillation Phase May Contribute to More Activity
DaSilva explained that the current phase of the El Niño Southern Oscillation may help to create conditions that are favorable for cyclonic development. ENSO, which encompasses El Niño, La Nina and a neutral phase, can influence atmospheric conditions in ways that either enhance or inhibit cyclone formation.
“We continue to trend toward a La Niña phase,” DaSilva said. “Even if one isn’t officially declared this fall, it is looking more and more likely that conditions will still behave like a La Niña. This means fewer periods of wind shear across the Atlantic, especially in October and November. This is what happened last year, and it led to a very busy end to the season. I think we can see a very busy end to the 2025 Atlantic hurricane season.”
The Source connected with Phil Klotzbach, Ph.D., a senior research scientist in the Department of Atmospheric Science at Colorado State University, for additional information about the current phase of ENSO.
“Currently, sea surface temperatures are slightly warmer than the La Nina threshold,” Klotzbach said. “We’re currently at about -0.4°C in the Niño 3.4 region, where NOAA measures sea surface temperatures for El Niño/La Nina, while the La Nina threshold is -0.5°C.”
“NOAA waits several weeks to make sure that the -0.5°C threshold is met to make sure it’s not a transient event. Therefore, the odds of La Nina being declared in the next few weeks are low,” explained Klotzbach. “However, whether the Niño 3.4 region is at -0.4°C or -0.5°C does not matter a tremendous amount in terms of the tropical circulation. Generally, a cool neutral ENSO phase, which we currently have, combined with a very warm Atlantic, which we also have, favors a busy hurricane season,” Klotzbach noted.
Local Weather Information and Staying Informed
Finally, the National Weather Service in San Juan, Puerto Rico, reminded individuals on Tuesday about weather-related threats that will continue to affect the USVI and Puerto Rico over the coming days, including the chance of rainfall and thunderstorms, particularly on Friday and into the weekend, gusty winds, and very warm temperatures with the potential for heat alerts.
It is crucial to remember that the forecast can change very quickly. USVI residents and visitors are encouraged to continue to remain prepared. Weather information is available from the NWS, the NHC, and NOAA.
Additionally, the local weather forecast for the U.S. Virgin Islands is regularly updated on the Source Weather Page and VI Source YouTube Channel. A weekly Tropical Outlook article from the Source is also published throughout hurricane season to provide in-depth updates.
Residents and visitors can find additional weather alerts and preparedness information from the Virgin Islands Territorial Emergency Management Agency.
St. Croix Source
Local news
