Michelle McCormick said WJCL is tracking a storm-force non-tropical low pressure area developing tonight off the southeast coast of the United States. The system has a near 0% chance of forming in the next 48 hours, but its 7-day chance rises to 40%.
Michelle McCormick on Gulf Stream track
McCormick said the low is likely to move slowly and erratically over the next couple of days while it stays non-tropical. Later this week, if it remains over the Gulf Stream, conditions could become more favorable for subtropical development.
She said a subtropical cyclone could form over the second half of this week as the system begins moving generally northeastward offshore of the eastern United States. That track keeps the system over open water for now, but it also leaves coastal conditions exposed along portions of the U.S. East Coast.
U.S. East Coast impacts
Regardless of development, McCormick said the system will cause high winds, coastal flooding, and dangerous surf along portions of the U.S. East Coast. The forecast does not hinge on the low reaching subtropical status before those effects arrive.
The practical issue for readers along the coast is timing. The system is already active, and its movement over the next couple of days will shape how quickly those conditions build through the rest of the week.
Subtropical cyclone by week’s end
A subtropical cyclone is a separate step from a non-tropical low, and McCormick’s forecast puts that transition over the second half of this week if the system stays over warmer water. For people near the coast, the question is not whether the low looks organized on a map, but when winds, flooding, and surf begin to worsen.
