DANNY to make reduced impact on Leeward Islands
General overview Sunday 23rd August 2015
Disturbance thirty has opened up into a very broad and weak area of low pressure centered well to the north of Bermuda. This has started to drift north-nor'east in the last four hours and by late tomorrow should turn sharply east before reaching Nova Scotia and will thereafter be off our interest radar with perhaps only passing interest to North Atlantic shipping. By this time tomorrow DANNY will have made a landfall somewhere in the Leeward Islands, but a much reduced storm from the spiteful little hurricane we saw two days ago.
Downgraded to a tropical storm overnight, now 230 miles east of Dominica and westbound at 14 knots. Upper level shear has effectively broken the back of vertical convection and the small 55 mile radius windfield is displaced from the cyclone centre and the eye has disappeared. As a consequence, the hurricane severity index rating has fallen to just 3 (1 for size and 2 for intensity) with winds of little over 40 knots. Impact on landfall will be blissfully lighter than originally indicated and onward into the Caribbean. Let's hear it for upper level wind shear.
Disturbance thirty one continues to show signs of organisation, now a day west of the Cape Verde Islands and moving west at a determined 22 knots. Conditions ahead are quite favourable now and this looks good for development into a decent tropical depression by Tuesday or Wednesday. By Thursday, at this speed, the system could be very near the northernmost Leeward Islands. Some forecasters are predicting this to reach tropical storm strength as it approaches the Caribbean.
Disturbance thirty two has sprung free of the African coast in the last few hours and is headed west at 15 knots. This also has some fertile conditions ahead and has a good chance of developing. Batten down in the Leeward Islands, otherwise stand easy.