A healthy disturbance moving through the central Atlantic – known as Invest 94L – has gradually organized since Tuesday and is on the verge of becoming the 20th tropical depression of the 2023 Atlantic hurricane season.
Watches are expected later today in anticipation of tropical storm conditions by as early as Friday for parts of the Leeward Islands in the northeastern Caribbean.
The missing piece for now is whether the system has a well-defined circulation at the surface. As the day progresses, our satellites should help to determine if winds are circulating completely around the low pressure center. If it doesn’t meet the criteria for a tropical depression by later today, NHC will likely initiate advisories on a Potential Tropical Cyclone in order to issue watches ahead of the organizing storm.
Forecast models have been at odds in recent days on how developed 94L may get by the time it nears its closest approach to the islands later this week. Models today appear to be coming into better alignment with a likely Tropical Storm Tammy or low-grade hurricane skirting the far northeastern islands of the Caribbean come Friday into Saturday.
Exactly how close the system gets to places like Dominica, Guadeloupe, and Antigua and Barbuda is still to be determined but the islands should prepare for the possibility of squally weather and tropical storm conditions (winds above 38 mph) to round out the week.
While Puerto Rico and the Virgin Islands should continue to monitor the forecasts – especially for the potential of heavy rain if the system slides farther west – models show a greater direct threat for now to areas east.
By next week, the system will get picked up by a jet stream dip and whisked out to sea and poses no threat to Florida or the mainland U.S.
A quiet end to October?
Elsewhere, the tropical Atlantic looks to be tapering down in the weeks ahead. We’ll keep an eye out for any late-season mischief – especially down in the Caribbean where conditions won’t be as hostile – but for now, models indicate a quiet end to October.
