Tropical Storm Gustav – downgraded from a hurricane after interaction with the mountainous terrain of western Haiti – made the expected turn to the west toward the Cayman Islands on Wednesday.
The official forecast track by the National Hurricane Center in Miami as of Wednesday afternoon showed the eye of Gustav passing very close to Cayman Brac around 7am Friday morning.
AccuWeather.com meteorologist Carl Erickson said people should not become too focused on the path of Gustav’s eye.
‘The effects will be felt well out ahead and away from the centre,’ he said. ‘All of the Cayman Islands will likely experience tropical storm force wind gusts at the least.’
Erickson agreed, however, that Cayman Brac and Little Cayman were most susceptible to facing hurricane-force conditions.
‘[Cayman Brac and Little Cayman] could be experiencing tropical storm conditions by [Thursday] night and hurricane conditions by early Friday morning.’
The exact track of Gustav was still subject to wide disparities on Wednesday, with some computer models still forecasting the storm to dip south to come very close to Grand Cayman and other models predicting a turn to the north, well away from even the Sister Islands.
Gustav’s meandering course on Wednesday did not help the forecasts, as the storm slowed and basically stalled after exiting the Haitian coast that morning. Erickson said the storm’s stall-out was likely a sign that the high pressure ridge to the north of the storm was intensifying.
‘When [cyclones] begin to slow down or stall like that, it’s often an indication of a transition and a change in direction.’
That is what happened with Gustav. After travelling northwest for several days, the storm turned toward the west Wednesday morning, although it only had a forward speed of 5mph.
The storm was predicted to pass in between northern Jamaica and southern Cuba, traversing very warm water along the way. Those high sea surface temperatures in combination with forecasted low wind shear are conducive for Gustav to regain hurricane strength, possibly as soon as Wednesday evening, Erickson said.
Cayman Island Chief Meteorologist John Tibbetts said the forecasts called for Gustav to intensify to anywhere between a Category 1 to Category 3 hurricane by the time it reached the Cayman Islands.
Mr. Tibbetts agreed that the Sister Islands were likely to feel tropical storm force winds by late Thursday night, and said Grand Cayman would likely start feeling strong winds by mid-morning Friday.
Based on the National Hurricane Center’s predicted path for Gustav as of Wednesday morning, Mr. Tibbetts said Cayman Brac and Little Cayman could expect to feel maximum sustained winds of 78 knots, with gusts up to 98 knots; and Grand Cayman could expect maximum sustained winds of 43 knots with gusts of 53 knots sometime Friday afternoon.
Storm surge did not appear in the computer models to be a major factor with Gustav, but rainfall could be. According to one prediction programme subscribed to by the Cayman Islands Meteorological Services, rainfall amounts from Gustav for Grand Cayman were expected to be 5.5 to six inches and nine to 10 inches for the Sister Islands.
On Cayman Brac, Sister Island’s District Commissioner Ernie Scott was urging residents not to drop their guard because of the storm’s weakening Wednesday morning.
‘The experts are telling us that it is going to become a hurricane once again,’ he said.
Mr. Scott said residents should know where they will ride out the storm and be there before nightfall Thursday. ‘By that time we definitely want people to be in the shelters because trying to operate in the nighttime is not easy.’
As of Wednesday morning, all visitors to Little Cayman had voluntarily left the island. Two Cayman Airways 737 jets were being made available later Wednesday afternoon for visitors still on Cayman Brac who wanted to leave. Shuttering of government buildings was completed Wednesday morning, Mr. Scott said.
‘We are taking full advantage of the fact that the forward movement has slowed a bit, although that could spell bad news for us. But we are grateful for the extra opportunity to get even more prepared.’
The District Commissioner said he did not expect Governor Stuart Jack to enforce a mandatory evacuation of Little Cayman to the Brac, as happened as Hurricane Dean approached last year. ‘That’s going to be the Governor’s call … but based on his statements after the Dean experience, I am not expecting there will be a mandatory evacuation order for Little Cayman.’