Five disturbances are seaborne
General outlook Tuesday 12th August 2014
From west to east -
Disturbance sixteen has shadowed disturbance fourteen across the Atlantic almost within towing distance and is now in the Bay of Campeche and expected to complete a similarly uneventful albeit damp home run into Mexico tonight.
Disturbance eighteen is a tropical wave passing the Lesser Antilles. It is producing some showers and storms as it moves west at 14 knots, but upper level wind shear is still the dominant feature aloft in this area.
I still think the frontal boundary off the Carolina coast is potentially dodgy, but that's seems to be not a widely shared view. Aerial images don't show any sign of rotation, but a patch of localised thunderstorms associated with the front has remained static for a couple of days and retreating pressure systems sometimes produce opportunities for development on their wake. If this were to develop, it is likely only to be a fish storm and head seaward.
Disturbance seventeen is westbound at an impressive 20 knots and almost midway between the African and South American coasts, still encountering dry air, but this is diminishing by the day and there is warm and wet air ahead. This may enable development of a tropical depression or weak tropical storm as the system nears the Caribbean this weekend. This has caused excitement and some track forecasts are already being mapped. The more reliable of these points this system to the north-western Caribbean and then towards Florida around the middle of next week.
Another agile low pressure cell has just emerged from the West African coast. This is disturbance nineteen. This is still going to encounter dry air, but much less than any of its predecessors and may develop later.