Two potential tropical developments close to the Caribbean

Monday 17th July 2017

From west to east –
Disturbance Fourteen is now ashore in Nicaragua and off radar. Not a peep from the guy in the hut.

Disturbance Fifteen is around 700 miles east of Trinidad and moving west-nor'west at 12 knots. Yesterday we identified a window of opportunity for this to develop before reaching the Windward Islands late tomorrow. The disturbance has spotted this too and formed a slight surface organisation, which may indicate that this is developing. Shipboard observers* have reported that the glass has fallen a little overnight - quite rapidly. This may therefore have a short burst as a tropical depression or even a weak tropical storm in the short term, but after a gusty and wet run ashore in the Windward Islands, westerly upper level shear awaits, which should put it back in its box.

Disturbance Seventeen is new. This has spun off from a tropical wave and is currently centred around 500 miles north east of the mouth of the Amazon. This is quite a large disturbance and may also have a window of opportunity. As this is already curving slightly north of west, this seems likely to bend away from the Leeward Islands and pass north east of the Caribbean islands. Nonetheless, this is making a decent web of squalls already and could also be set to upgrade to a depression or a tropical storm within the next few days, but once past the north east Caribbean, upper level wind shear will be there to spoil the party.

Weather watch in the Windward Islands - otherwise stand easy.