Forecasters Watching Tropical Storm Joaquin as It Churns in Atlantic

Forecasters are watching Tropical Storm Joaquin as it churns in the Atlantic near the Bahamas to see if it will become a threat to the U.S. East Coast later this week.

Joaquin was about 385 miles (620 kilometers) northeast of the central Bahamas with winds of 40 miles per hour as of 5 a.m. East Coast time, the National Hurricane Center said in an advisory. It was moving west at 5 mph.

The storm’s structure and larger weather patterns are making it difficult to know exactly where Joaquin will end up.

“Needless to say, confidence in the details of the track forecast, especially beyond 48 hours, is extremely low,” Michael Brennan, a senior hurricane specialist at the center, wrote in an analysis.

Joaquin is the 10th storm of the six-month Atlantic hurricane season that ends on Nov. 30. Current track outlooks call for it to move parallel to the U.S. East Coast and be off the Virginia coastline by Sunday.

However, computer forecast models are having trouble determining the strength of a low-pressure trough that is predicted to set up over the southeastern U.S, Brennan said. This weather pattern will help control where Joaquin will go.

Determining Track

How strong and well-organized Joaquin is will also determine its path and how it moves.
Right now, Joaquin is being torn apart by wind shear, said Rob Carolan, a meteorologist at Hometown Forecast Services Inc. in Nashua, New Hampshire. The storm’s movement has also slowed.

“I think you are going to see a lot of run-to-run disparity in the models,” Carolan said.

Monday, some models called for the storm to drive itself into the East Coast. Carolan said that prediction has since faded. “Anyone who says they have any confidence in where it is going to go is lying to you.”

Another possibility is for a frontal system moving across the eastern U.S. to absorb Joaquin and destroy it.

What is likely is that the U.S. Northeast, including New York, will get drenched from “fire-hose precipitation,” Carolan said. This will be in addition to heavy rain falling on the area from other weather systems through Wednesday.

“I don’t think Joaquin ends up being a wind event; I think the big concern is the rain,” Carolan said.