Fish storm GASTON and potential hurricane in northern US Gulf.

Wednesday 24th August 2016

Tropical storm GASTON is centred around 850 miles west of the Cape Verde Islands and moving west-nor'west at 15 knots. Wind speeds are now gusting 70 knots and this is likely to hit hurricane strength very soon and further intensification is expected. A tropical storm force wind field radius of 90 miles has been reported and this is also expected to increase. Warm waters lay ahead with only a slim hope of upper level shear a couple of days away. This will move in a west-nor'west to northwesterly direction over the next few days before recurving toward the north and then northeast to pass about 600 miles east of Bermuda. GASTON is going to be deeply unpleasant news indeed for seafarers unfortunate enough to find themselves in the central Atlantic, having a clearly defined eye and lusty eye wall formation, but will not impact any land areas.

With the greatest respect for the plight of affected seafarers, GASTON is not the problem today and the prospects for disturbance twenty six are potentially more worrying. The disturbance is currently 120 miles south-east of San Juan with winds of just 30 to 40 knots. It entered the eastern Caribbean this morning bringing with it heavy, gusty showers and storms over the islands of the northeast Caribbean. By this weekend, it is forecast to become a tropical storm near the Bahamas. From there, the consensus was, until an hour ago, a westward track into Florida by late Saturday and into the eastern Gulf by Sunday with conditions right for this to develop into a strong tropical storm or a hurricane with a sharp turn to the north and a landfall over the Florida panhandle. This has changed in the last hour. Each time a low pressure cell interacts with land, it introduces uncertain track forecasts. This disturbance will interact with the Leeward Islands, the Bahamas, Hispaniola and even a glance at eastern Cuba before crossing Florida into the eastern Gulf, so there is much uncertainty thereafter. At present, this has a hurricane severity index of just 1 (zero for size and 1 for intensity) but has a predicted maximum of 23 (12 for size and 9 for intensity) when it digs in after passing Florida which is about a category 2 hurricane. Now, a number of commentators are suggesting that this will not turn north to the east of Florida but a shifting high pressure system may block its northward progress and cause a westerly track, with a wide variety of landfall options from the Mississippi coast to as far west as Texas. To add to the bad news, a predicted category 2 hurricane may be a little light. Certainly, the European modellers are predicting a category 4 hurricane. Offshore oil interests will be executing their hurricane response plans across the entire northern Gulf of Mexico.

A weather watch needed in the central Atlantic and on disturbance twenty six, otherwise stand easy.