Tropical system could form southwest of the Azores

A low-pressure system in the eastern subtropical Atlantic is showing signs of becoming more organized, with tropical development possible later today or tonight.

The system, designated AL99, is located several hundred miles southwest of the western Azores. Showers and thunderstorms have become more concentrated near the centre of the low since Friday.

The system is expected to move north-northeast at about 5 mph while remaining well southwest of the Azores.

Forecasters say a short-lived tropical depression or tropical storm could form later Saturday or Saturday night. However, upper-level winds are expected to become less favourable for development beginning late Sunday.

The National Hurricane Center gives the system a 90 per cent chance of tropical formation over the next 48 hours, with the chance remaining at 90 per cent over the next seven days.