From west to east:

Revitalised Disturbance Ten is crossing the northern edge of the Bay of Campeche headed west-nor’west at 10 knots. Upper level wind shear is getting the better of the vertical formation and this is likely to disappear without further development.

As anticipated, Disturbance Twelve dug in and has formed tropical storm ELSA, which is the talk of the day. Currently 650 miles east of Trinidad and moving west at a brisk 25 knots, this has enough energy to overcome both upper level wind shear (albeit diminishing), and the negative effect that its own ground speed would normally produce. ELSA will cross the Windward Islands tomorrow as a fairly robust tropical storm. Interaction with the islands may cause deceleration but in any event, will move  quickly across the north-eastern Caribbean towards Cuba. The general consensus is a turn thereafter across Cuba and into the eastern Gulf of Mexico, with a northerly track to the west of the Florida peninsula towards a landfall along the north-eastern Gulf coast on Tuesday. With at least two land masses to cross and an as yet undetermined turn to starboard, the experts’ assurances that this will pass clear of the peninsula as a weakened tropical storm are in my view premature and unreliable, at this stage. What can be predicted with reasonable certainty is intensity as it makes first landfall over the Windward Islands. A hurricane severity index rating of 6 out of 50 (being 2 for size and 4 for intensity) is most likely, which translates into winds gusting 65 knots over a windfield radius of 110 miles with heavy rain and potential localised flooding. Aerial imagery shows the convection column displaced slightly north of the storm centre, which would indicate the general area of the storm’s worst excesses when it makes landfall.

Three days in the wake of ELSA, Disturbance Fifteen is now around 850 miles north-nor’east of the mouth of the Amazon. This is westbound at 15 knots but as yet showing no signs of organisation.

Stand by for tropical storm conditions across the Windward Islands.

Image Marc Dorsel