Storm clouds gathering as ERIKA heads west
General overview Tuesday 25th August 2015
The Caribbean wall of upper level shear sent DANNY went from hero to zero in a very short time and all that now remains is a westbound low pressure wave producing some heavy rain over the Virgin Islands and Puerto Rico. Some localised flooding is possible today before the system dissipates completely.
Today's meteorological sweetheart is tropical storm ERIKA. Currently 590 miles east of the Leeward Islands on a slightly north of westerly heading at 18 knots. Three factors have a bearing on this storm's development over the next day or so. Ground speed is too high for significant development, wind shear is already buffeting the vertical structure and the cyclone is rattling across the cobbles of dry air which put DANNY to the sword. These factors are however temporary, and on the anticipated track slightly to the north of that of DANNY, wind shear will put the brakes on forward progress, dry air will give way to wet air and the system will slip to the north of the wind shear belt. It is entirely possible that ERIKA will weaken then develop again as it brushes the northernmost Leeward Islands. Thereafter, there is great uncertainty between the various commentators ranging from a track towards the Florida peninsula and into the eastern Gulf (albeit but no further west) , a landfall in south eastern Florida, a fly-by between Florida and the Bahamas or a landfall in the Bahamas. Intensity is also tough to call. It is likely that this will recover tropical storm status, and one commentator is even suggesting a hurricane. The current hurricane severity rating is 3 out of a possible 50 points (1 size, 2 intensity). A predicted maximum of 6 out of a possible 50 points (2 size, 4 intensity) is being given, but this is far too speculative to be of any practical use as this is still five to six days ahead.
Disturbance thirty two, a day or so west of the Cape Verde Islands is west bound at 15 knots. This has tracked a little to the north into dry and air and is discovering the difficulty of cyclonic development in Saharan sand and is currently unlikely to pose any threat.