DANNY deepening and heading west
General overview Thursday 20th August 2015
Disturbance thirty is now defined by an upper level low and a surface trough. Winds within are freshening and there is a chance that this could creep into subtropical storm status. As far as surface motion is concerned, this is still dithering more or less due south of Nova Scotia and due east of New York having drifted west overnight. This is still more likely to curve to the north and east, but will remain seaborne and cause only gusty winds and local heavy rainfall to coastal Canada next week.
Tropical storm DANNY is currently centred 990 miles east of Barbados and on a westerly heading at a leisurely 10 knots. The system has a current hurricane severity index rating of 3 (1 for size and 2 for intensity) with a predicted peak of 8 (3 for size and 5 for intensity), although we'd suggest this is a little low. Sustained winds are estimated to be near 45 knots with gusts up to 60 knots with a 60 mile radius windfield, however surface and vertical organisation have improved and the associated winds are increasing. Aerial thermal images overnight have shown DANNY teasing observers with a ‘now-you-see-it-now you-don't' warm spot. This is indicative of eye development. If this continues, DANNY could become a hurricane later today. We have polled 19 observers and all have DANNY reaching the Caribbean across a wide sweep, but the more reliable modellers seem to be favouring the northern Leeward Islands and some - who we would be inclined to agree with - opting for this cyclone reaching Hispaniola. The unknown factor here is the effect of dry air which could take the sting out of this before landfall. It is important to note that this is very slow moving which can aid development but also cast doubt on forecast tracks. None of the modellers we have checked out this morning have DANNY making the Gulf of Mexico. Not even the Canadian guy.
Disturbance thirty one is now a day west of the Cape Verde Islands and moving west at 10 knots. A west-nor'west motion is expected over the next week with a reasonable chance of becoming a depression at some time. Early days.
Batten down in the western Atlantic, otherwise stand easy.