Tropical Depression 7 formed in the central Caribbean Monday morning and became Tropical Storm Gustav with 60mph winds in the afternoon.
The cyclone was expected to become a hurricane by Tuesday afternoon.
Although the official forecast by the National Hurricane Center in Miami indicated Gustav would head northwest toward Haiti and eastern Cuba, there remained a high degree of uncertainty on its long-term path. Several computer models showed the system bending westward toward Central America in the coming days, while others had it heading toward South Florida or the Bahamas.
Tom Kines, a meteorologist with AccuWeather.com said there were two main reasons for the uncertainty of the Gustav’s path.
‘Number one, the steering flow is very weak,’ he said. ‘Number two, there are two weaknesses, so to speak, in the upper air patterns.’
Kines said there was one ridge centred over Florida and another centred farther east in the Atlantic. Depending which weakness affects the cyclone more, Gustav could head either northerly or westerly.
‘If this thing wobbles in a more westerly track, it could lead to an ending track that would be more favoured toward western Cuba and the Gulf [of Mexico]. Then it could affect [the Cayman Islands].’
However Kines said the storm system was no immediate threat to the Cayman Islands.
‘It just depends on which direction it meanders,’ he said. ‘But our gut feeling is it is more of a threat for Florida.’
Regardless of long-term track, Gustav was forecast to make an initial landfall in Haiti – possibly at hurricane strength – and bring life threatening flash floods and mud slides from intense rainfall.
Hazard Management Cayman Islands issued a statement Monday morning saying it was closely monitoring the cyclone.
‘Residents of the Cayman Islands should remain alert and stay tuned to the local media for updates,’ it stated.
Gustav was not the only storm system brewing in the Atlantic basin. Two areas of low pressure associated with tropical waves were moving westerly across the Atlantic Ocean Monday, with one of them projected to develop into a cyclone.
‘The overall weather pattern favours tropical activity over the next few weeks,’ said Kines, adding that low wind sheer was one of the factors supporting the favourable pattern.
Historically, the peak hurricane season in the Atlantic basin occurs between mid-August and late October, with 10 September the acme.