Subtropical Storm Leslie just won’t give up. The storm has puttered around the central Atlantic for the past week and it’s not going anywhere anytime soon. Thankfully, the storm is no threat to land at the moment, but the storm’s size and longevity means that there’s a chance of big waves and rip currents along just about every coast that faces the Atlantic in the coming days.
Like many storms we’ve seen in the Atlantic this year, Leslie’s origins are not tropical in nature. The storm formed from the same upper-level trough that swept Hurricane Florence out of the Carolinas two weeks ago. A little bit of Florence’s remnant energy and moisture went into the creation of this storm. The storm grew organized enough to become Subtropical Storm Leslie last weekend before losing organization earlier this week as it succumbed to a hostile environment.
The storm regenerated on Friday afternoon, and the National Hurricane Center expects Leslie to stick around for the long haul. Leslie is currently a subtropical storm, but it’s expected to transition into a fully-tropical storm this weekend and possibly reach hurricane strength by the middle of next week.
The term “subtropical” is a technical detail that does more to confuse people than serve any practical purpose. A subtropical storm is a storm that’s tropical-like. It exhibits some tropical characteristics. Even though it’s not a full-fledged tropical system, a subtropical storm like Leslie is close enough to a tropical storm, and has effects that are similar enough, that the NHC treats it as if it were fully tropical by assigning the storm a name and issuing forecasts, watches, and warnings.
This could be one of the longest-lived storms we’ve seen so far this year. The latest forecast from the NHC shows Leslie meandering toward the southwest through the middle of next week. After that, weather models hint that the storm will linger somewhere in the central Atlantic for a while longer—the storm may still exist beyond next weekend.
Two weeks is a long time for a storm to dawdle over the same region of the ocean. Leslie is likely to disrupt some shipping lanes, but that’s about it for direct impacts for now. The immense churning of the ocean will drive rough surf thousands of miles from the storm, bringing the potential for high waves and rip currents to pretty much every coast that faces the Atlantic Ocean, including the U.S. East Coast. Local authorities may restrict or prohibit going in the ocean in spots. It’d be wise to obey these instructions even if the weather is clear and calm.
It’s too soon to tell what will become of Leslie. The storm is expected to linger for so long that the storm’s ultimate fate is beyond the reliable reach of weather models. The most likely scenario is what usually happens to storms in this part of the Atlantic. The storm will probably either peter out or an approaching upper-level trough will force the storm to lose organization and rocket toward the northern Atlantic. It looks highly unlikely right now that the storm will pose any direct threat to the United States. However, hurricane season isn’t over for another couple of weeks, and it’s a good idea to keep track of the tropics for any other threats that may pop up between now and then.