A storm-force low-pressure system off the US East Coast has a 40% chance of briefly developing into a subtropical storm, the National Hurricane Center (NHC) has said.
The non-tropical system, currently a few hundred miles off the mid-Atlantic coast, is producing showers and thunderstorms as it moves slowly north-eastwards over the Gulf Stream.
Subtropical storm could be named Josephine
Forecasters said the low could gradually lose its frontal characteristics over the next day or two, allowing it to acquire subtropical features before accelerating away from the eastern United States later this week.
If it reaches subtropical-storm status, it would be named Josephine, the next name on the 2026 Atlantic storm list.
The NHC said the system had a 40% chance of developing within 48 hours and the same probability of development over the next seven days. Conditions are expected to become less favourable for further tropical or subtropical development once it moves away from the US coast.
Regardless of whether it strengthens, the system is expected to bring high winds, coastal flooding and dangerous surf to parts of the US East Coast over the next few days. Local weather authorities have advised people in affected coastal areas to monitor forecasts and any warnings.
The system is expected to track north-eastwards away from the United States and poses no direct threat to Florida.
