Thunder and heavy rain as FIONA shapes up for north-eastern Caribbean
From west to east:
We picked up a disturbance forming over west Africa three days before the professional agencies who even after launch, dismissed this as a non-starter. This was not our view. Now, there are early whispers of this becoming a hurricane. Disturbance Thirty deepened overnight and has formed Tropical Storm FIONA. Currently just under two days east of the northernmost Leeward Islands headed west at 12 knots, this cyclone is producing some impressive thunderstorms with winds gusting 60 knots with a windfield radius of 100 miles, which equates to a hurricane severity index (HSI) rating of 3 out of a possible 50 points (1 for size and 2 for intensity). FIONA is feeling the effect of some upper level shear which should persist until it enters the north-eastern Caribbean as a heavy rainmaker but environmental conditions thereafter will become more fertile for development although there is likely to be some weakening as it moves near or over Puerto Rico and Hispaniola on Sunday. There is still some uncertainty over its track beyond Hispaniola. Some modellers take FIONA towards the Bahamas, while others take the storm more to the north. The stronger FIONA becomes over the Caribbean, the further north and east it is likely to move over the southwest Atlantic. The smart money is taking FIONA east of the Turks and Caicos Islands and the south-eastern Bahamas before a turn to the north. At this time, conditions are likely to be favourable for intensification and hurricane intensity cannot be ruled out. Track and intensity are vague but it would seem that this will not reach the Gulf Of Mexico.
Disturbance Thirty One is now two days north-west of the Cape Verde Islands moving to the west-nor’west at 15 knots. This is drifting clear of the fertile tropical convergence zone and is unlikely to develop or indeed, survive.
Disturbance Thirty Two is centred 200 miles south-east of the Cape Verde Islands moving to the west at 10 knots. A slight acceleration is expected over the next day or two but at this stage, development is not expected.
Weather watch for the north-eastern Caribbean otherwise stand easy.