The National Hurricane Center is monitoring hurricanes Imelda and Humberto in the Atlantic basin. While the storms are not expected to impact the U.S. Virgin Islands directly, rough surf and rip currents are possible, and forecasters say the Atlantic will remain active with chances for additional development in October.
Hurricanes Imelda and Humberto
As of Tuesday afternoon, hurricanes Imelda and Humberto remained active in the Atlantic, several hundred miles apart. Imelda, a Category 1 hurricane near the Bahamas, is forecast to pass near or directly over Bermuda on Wednesday, where a hurricane warning is in effect. Humberto, also a Category 1 hurricane, was located farther north, west of Bermuda. Areas across the Bahamas, Bermuda, and portions of the southeastern U.S. are expected to continue experiencing impacts from the storms, including rainfall and gusty winds.
Neither system poses a direct threat to the U.S. Virgin Islands or Puerto Rico. However, swells generated by the storms will produce choppy seas across much of the Atlantic basin, and marine conditions will be rough across the local region.
Imelda, which initially was designated Invest 94L as it passed across the USVI and Puerto Rico last week, brought wind and rainfall to areas of the Bahamas over the weekend. As of Tuesday evening, the cyclone was packing winds of approximately 90 mph and is forecast to continue strengthening as it travels toward Bermuda.
Official Forecasts from the National Hurricane Center
“At 5:00 p.m. EDT, the center of Hurricane Imelda was located near latitude 29.4 North, longitude 75.5 West. Imelda is moving toward the east-northeast near 12 mph,” the NHC said. “A generally east-northeastward motion at a faster forward speed is expected over the next couple of days. On the forecast track, the center of the hurricane will approach Bermuda Wednesday afternoon. Maximum sustained winds are near 85 mph with higher gusts. Some additional strengthening is forecast during the next day or so.”
The NHC also noted that Hurricane Humberto is forecast to remain over open water and will gradually lose strength as it passes west of Bermuda.
At 5:00 p.m. AST, the center of Hurricane Humberto was located near latitude 34.0 North, longitude 69.5 West. Humberto is moving toward the north near 17 mph. A turn to the northeast is expected later today, followed by a faster east-northeast motion on Wednesday and Thursday. On the forecast track, the center of Humberto will pass west of and then north of Bermuda today and Wednesday. Maximum sustained winds are near 80 mph with higher gusts. Continued weakening is forecast and Humberto is expected to become a strong extratropical system on Wednesday,” according to the NHC.
Some wind and rain impacts are still expected across Bermuda, and the storm will continue to generate choppy seas throughout much of the Atlantic basin.
“Swells from Humberto are likely to cause dangerous surf and life-threatening rip current conditions, affecting beaches of the northern Caribbean, Bahamas, Bermuda, and much of the east coast of the United States over the next several days,” the NHC said.
Local Impacts for the Virgin Islands and Puerto Rico
On Tuesday afternoon, the Source spoke with Manuel Ramos-Rodriguez, a meteorologist at the National Weather Service in San Juan, Puerto Rico, about the two hurricanes positioned north of the U.S. Virgin Islands and Puerto Rico. Ramos said that while neither storm is expected to directly impact the islands, both Imelda and Humberto are forecast to generate rough seas and an elevated risk of rip currents later this week. Marine alerts may be issued as conditions develop.
“A large, long-period northerly swell arriving by late Thursday night will promote hazardous marine and beach conditions across the islands, persisting through at least Sunday or early next week,” the NWS warned. A period of a swell indicates the time between breaking waves.
Hurricane Expert Insight
The Source also reached out to Alex DaSilva, AccuWeather’s lead hurricane expert, to learn more about Imelda and Humberto, as well as any potential tropical weather threats in the coming days.
DaSilva explained that hurricanes Imelda and Humberto have been interacting in a relatively rare fashion, known as the “Fujiwara Effect,” named after a Japanese meteorologist, which occurs when nearby storms influence each other’s movement.
“When two hurricanes spinning in the same direction pass close enough to each other, they begin an intense dance around their common center. If one hurricane is a lot stronger than the other, the smaller one will orbit it and eventually come crashing into its vortex to be absorbed. Two storms closer in strength can gravitate towards each other until they reach a common point and merge, or merely spin each other around for a while before shooting off on their own paths. In rare occasions, the effect is additive when the hurricanes come together, resulting in one larger storm instead of two smaller ones.”
In a separate interview in LiveScience, DaSilva explained that “the influence from the much stronger and larger Humberto will tug at Imelda and help pull the storm away from the U.S. and out to sea.”
“The Fujiwara Effect is occurring right now, as Imelda and Humberto are about 500 miles apart, well within the 850-mile threshold for this to happen,” DaSilva told the Source on Tuesday. “It’s quite rare for this to occur in the Atlantic basin and is more common in the Western Pacific, where there are more space and more storms in an average year. The last notable Fujiwara Effect in the Atlantic I can recall was in 2016 with hurricanes Matthew and Nicole.”
“These interactions can make forecasting much more challenging, because storm tracks become more erratic. We know storms rotate counterclockwise around each other, but they can wobble and shift in unpredictable ways, which can cause model uncertainty,” DaSilva added.
While the Fujiwara Effect has indeed influenced the trajectory of Imelda, forecasters do not expect the two storms to merge.
Possible Cyclonic Development in October
The Atlantic hurricane season lasts for approximately two more months, officially ending on November 30. DaSilva noted that there is still plenty of time for tropical development to occur, including the potential for systems to organize and possibly affect the local islands, especially through the middle of October.
Notably, he advised individuals across the Caribbean to keep an eye on a tropical wave that is forecast to emerge off Africa this week for possible organization.
“We’re still in the tropical wave season, which usually continues through mid-October,” DaSilva said. “AccuWeather meteorologists are watching a tropical wave expected to move off Africa in the next couple of days, and some models are hinting at development. However, overall, the chance looks low because of wind shear ahead of it, and if it does develop, it wouldn’t be until after Oct. 8. Therefore, any potential impact to the U.S. Virgin Islands would be at least 10 days away. It’s still very far out, but it’s worth monitoring,” he emphasized.
“After mid-October, the number of tropical waves coming off Africa drops off significantly, and climatology tells us it becomes much harder for storms to develop in the eastern Caribbean,” DaSilva stated. “That said, we have seen storms as late as November, and with waters still quite warm this year, we can’t say the chance is zero. While the odds of impact to the Virgin Islands are lower after October 15, we still need to keep watch through the end of the season.”
A Potentially Busy Second Half of the Season
DaSilva reported that forecasters are still expecting a potentially active period of tropical activity through the remainder of the season. He also shared an update on the current conditions of the El Niño-Southern Oscillation, which can affect cyclonic development across the Atlantic.
“We still anticipate a busy second half of the season, and we’re seeing signs that the atmosphere is starting to behave like a La Niña as waters in the eastern Pacific cool,” DaSilva confirmed.
“That tends to reduce wind shear and can allow for more storm development late in the season. Last year, this type of weather pattern led to a very active October and November, and while I don’t think it will be quite as busy this year, we could still see some significant storms. I’m especially concerned about the Western Caribbean and the Gulf, where waters remain largely untouched. Those areas could support explosive development if the right conditions come together,” he concluded.
NOAA Global Tropics Hazards Outlook
According to a Global Tropics Hazards Outlook released Tuesday, there will continue to be an elevated chance of cyclonic development across portions of the Atlantic basin in the coming weeks. The forecast tool, which is issued every Tuesday by NOAA’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 areas across a portion of the Main Development Region of the Atlantic basin – the zone between the west coast of Africa and the Caribbean – may experience a 20-40% chance of tropical development during the “Week Two” outlook period, which runs from Oct. 8 until Oct. 14. Development is not forecast across the Main Development Region in the “Week Three” outlook, running from Oct. 15 through Oct. 21.
However, according to the forecast, areas across the Western Caribbean Sea and the Gulf are likely to see an elevated chance of tropical cyclogenesis at times in October.
Additionally, the Eastern Pacific basin, which remains active, is also expected to experience an increased risk for cyclonic development in the coming weeks.
Local Weather Information and Staying Informed
Finally, the NWS has reminded residents and visitors of ongoing weather-related threats for Puerto Rico and the USVI, including the possibility of showers and thunderstorms, as well as very warm temperatures, which could prompt heat alerts across the region.
Additionally, marine conditions will be hazardous due to nearby tropical systems, and marine alerts may be issued in the coming days.
The forecast can change very quickly, and USVI residents and visitors are encouraged to continue to remain prepared. Weather information is available from the NWS, the NHC, and NOAA.
The local weather forecast for the U.S. Virgin Islands is also regularly updated on the Source Weather Page and VI Source YouTube Channel. Additionally, A weekly Tropical Outlook article from the Source will be 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.
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