Meteorologists say the Atlantic basin may be entering a brief lull in tropical activity, though conditions are expected to turn more favorable for cyclone development in September, when hurricane season reaches its climatological peak.
As of Wednesday, the National Hurricane Center continued to monitor Tropical Storm Fernand in the North Atlantic, though the system is expected to dissipate soon. Additional development is considered unlikely over the next seven days, according to the agency’s outlook.
The pause comes as factors, including dry, dusty Saharan air, remain across the Atlantic Main Development Region, creating hostile conditions for tropical waves to organize. With limited moisture and unfavorable vertical winds, storm formation is forecast to remain suppressed into early September.
Hurricane Forecaster’s Perspective
The Source contacted Alex DaSilva, AccuWeather’s lead hurricane expert, to better understand why the Atlantic may not support tropical development in the coming days.
“Currently, Saharan dust and dry air conditions are present across the Atlantic basin, which can help to inhibit development, and there is also a lot of sinking air in the Atlantic basin,” DaSilva said. “For active patterns to develop, you usually look in areas of high moisture and good vertical motion. Through at least Sept. 3, we expect dry and sinking air to dominate across the Main Development Region. This will make it very hard for tropical waves to develop,” he explained.
DaSilva cautioned that, while current conditions may make it difficult for tropical cyclones to develop, pauses during hurricane season don’t usually continue for a long period of time. He noted a possibility of some development off the southeast U.S. coast, though the NHC has not highlighted the area as of Wednesday.
“While pauses like this are unusual, they are not unheard of, and there was a long pause last year as well,” DaSilva said. “Still, it’s rare to go through a Labor Day holiday weekend without a named storm in the Atlantic basin, and in 2024, there were also no cyclones on Labor Day. It’s been more than 30 years since we experienced back-to-back Labor Days without a named storm in the Atlantic basin. The last time that happened was in 1991 and 1992. This could happen again this year if nothing develops off the southeast coast.”
How Long Will the Pause Last?
Assuming no cyclones develop in the coming days — which forecasters caution is never guaranteed — the question becomes how long the quiet stretch could last. DaSilva shared his thoughts on when conditions may turn more favorable for tropical development. He explained that a Madden-Julian Oscillation wave may approach the region in the coming weeks, enhancing development potential.
The National Weather Service defines the MJO as “an eastward-moving disturbance of clouds, rainfall, winds and pressure that traverses the planet in the tropics and returns to its initial starting point in 30 to 60 days on average.”
“I think things will pick up during the end of the first week of September and beyond,” DaSilva said. “It looks like there will be an MJO wave coming through, which can help to increase shower and thunderstorm activity across the basin. There will also be more vertical motion across the basin, which can help lead to more storms.
“Also, we expect the dry, dusty air to back off a little bit during this time,” he said. “Atmospheric conditions conducive to tropical development are forecast to return by the end of the first week of September, just as cooler water temperatures rebound in the wake of Hurricane Erin. The tropics could be quite active by mid-September,” DaSilva added.
“Sea surface temperatures in the Gulf are extremely warm. This concerns me a lot because if a storm is able to get into the waters of the Gulf, it could rapidly intensify,” DaSilva cautioned.
Nearing the Peak of Hurricane Season
Indeed, the Atlantic hurricane season reaches its climatological apex around Sept. 10, with the majority of storms forming between the second half of August and early October. As sea surface temperatures remain elevated and vertical wind shear begins to relax, residents across the USVI and Puerto Rico are advised to remain vigilant — even during this current lull — for signs of renewed tropical development in the weeks ahead.
As the season approaches its peak, DaSilva said another weather phenomenon to watch is the El Niño–Southern Oscillation. ENSO, which encompasses El Niño, La Nina and a neutral phase, can influence atmospheric conditions in ways that either enhance or inhibit cyclone formation.
“Officially, we are in a neutral phase of ENSO. So that means that water temperatures along the equator in the Eastern Pacific are near average,” DaSilva said. “It is worth noting that we have seen a cooling trend in this area over the last few weeks,” he added.
“Back in March, when we released our forecast for the season, we were concerned that we could start to see a shift toward a La Niña during the second half of the season,” DaSilva stated. “This is what happened last year, and we saw a very active second half of the season. While La Nina technically was never declared during the 2024 hurricane season, it got close enough that the atmosphere started acting like a La Niña.”
“I have the same concern for this year,” DaSilva warned. “La Nina typically yields more activity in the Atlantic due to less frequent periods of vertical wind shear. Tropical storms and hurricanes are more likely to develop in areas with lower wind shear. I would expect a very busy second half of the season across the basin,” he predicted.
NOAA Global Tropics Hazards Outlook
Looking ahead into September, the likelihood for tropical development is expected to increase, according to a Global Tropics Hazards Outlook released Tuesday, Aug. 26. 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 the Atlantic basin may experience a 20-40% chance of cyclonic development across the Main Development Region — the zone between Africa and the Caribbean — during the ‘Week Two’ outlook period, which runs from Sept. 3 until Sept. 9. A 40-60% chance of tropical cyclogenesis is forecast in the ‘Week Three’ outlook, running from Sept. 10 through 16.
Areas across the western Caribbean Sea and the southwestern Gulf are also anticipated to see an increased chance of development.
Meanwhile, the Eastern Pacific basin, which continues to remain active, is also expected to experience an elevated risk for cyclonic development in the coming weeks.
NWS Details and Local Weather Forecast Information
While it comes as good news that the tropics are relatively quiet, the NWS in San Juan, Puerto Rico, has warned that temperatures will be very warm, particularly on Thursday and Friday. The agency continues to remind residents to stay as cool as possible to avoid heat-related illnesses.
A weak tropical wave, located east of the Leeward Islands as of Wednesday afternoon, may also help increase the chance of precipitation across the local islands.
“For the U.S. Virgin Islands, heat advisory conditions are expected during the second part of this week, and passing showers will continue to move through from time to time,” forecasters at the NWS said on Wednesday afternoon.
Finally, a fading northerly swell may continue to result in choppy seas and an elevated risk of rip currents. Swimmers and boaters are advised to exercise caution.
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 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.
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