CHANTAL racing across the north eastern Caribbean

General outlook 9th July 2013

Oddball disturbance fourteen is now causing thunderstorms and showers over the Bahamas and into Florida in the next few hours whilst losing surface organisation as it moves west at 5 knots into residual wind shear from this week's busy high altitudes. Over the next few days, disturbance fourteen will clip southern Florida and then turn towards the north into the eastern Gulf of Mexico where it will merge with an upper level trough. Despite its unusual formation and track, and the early hopes of some enthusiastic modellers, tropical development is not expected.

All eyes today on tropical storm CHANTAL, currently centred just to the north of Martinique headed west-nor'west at a logic defying 25 knots. This has a maximum windfield of around 100 miles, with peak winds at the centre of 55 knots. The current HSI is 5 (2 size /3 intensity), and a forecast maximum 6 (2 size /4 intensity).

Satellite imagery of CHANTAL looks disorganised, possibly due to its extravagant and unnecessary high ground speed, however reported to be well defined on the ground. Reconnaissance aircraft data suggest that the central pressure has fallen and that flight level winds support surface winds near 55 knots. Some wind shear is expected to impact CHANTAL as it moves across the Caribbean but not enough to prevent some slow strengthening. CHANTAL could be just short of hurricane strength when it reaches the Dominican Republic on Wednesday. The system will then weaken as it crosses Hispaniola but slowly restrengthen as it moves through the Bahamas later in the week and through the weekend and then decelerate. The question being asked is which way will CHANTAL go. The ridge that has been such a feature this week over the Gulf coast will be the decider. If this ridge builds, it is possible that CHANTAL may head west into the Gulf. If it weakens, east towards the Carolinas. If it remains unchanged, on the current track - ashore over northern Florida. I wouldn't say any of the three are certainties yet.

Disturbance sixteen is around three days west of the Cape Verde Islands and racing west – also at an energy-wasting speed of 20 knots which will prevent development. Satellite imagery shows a rather weak cloud system and a dismal future.

The disturbance seventeen which we reported on yesterday as having a rather well developed cloud system and a determined look to it as it left the African coast has been recognised and designated disturbance seventeen. This is attracting some attention and some modellers are expecting this to develop.

Stand by in the north eastern Caribbean where storm cones are aloft.