Barbados Meteorological Services
Initial to 4 days discussion based on Satellite imagery,BMS Radar composite,S.P.I.E products,GEM, GFS, WW3, UKMET and BMS WRF modeling, surface and upper air observations, Satellite derived products.
DATE: 20181113 PERIOD: Evening
Today: A surface to low level trough system drift over the northern half of the island chain, generating cloudy to overcast skies with scattered moderate to heavy showers and isolated thunderstorms over some of the islands in the region. This prompted a flash-flood warning to be issued for Dominica at midday and will continue until 6:00 pm today. While over the southern half of the island chain, trailing moisture from the trough system generated some weak instability over the area resulting in cloudy skies with some scattered showers and a few light periods of rain.
Further south, over Trinidad and Tobago and the Guianas, mixed weather conditions were observed for most of the morning session. However, during the afternoon, a low to mid level trough position over Suriname generated cloudy skies with moderate to heavy thunderstorms over the area.
Wind speeds across the region were fairly brisk ranging between 6 to 22 knots. While Sea conditions over the region were moderate to rough in open water with swells peaking at near 3.0m.
Today: The surface to mid level western Atlantic high pressure system was the dominant feature across the basin. As a result, mostly fair weather conditions were experienced over the area. However, across the Greater Antilles from Hispaniola eastwards to Puerto Rico and the Virgin Islands elevated moisture ahead of the a weakening area of disturbed weather, generated some instability over the area, which resulted in cloudy skies, scattered showers and moderate to heavy periods of rain being spread over the area. Some convective activity was also observed over these parts. A favourable upper level diffluent pattern also continued to add some support.
Tonight : The surface to low level trough will continue on its westward motion across the Caribbean Sea. However, moisture trailing its axis will maintain partly cloudy to occasional cloudiness and showers across the island chain with the more prominent showers and thunderstorms across the Leewards, north and central Windwards. Some additional enhancement will be provided by a persistent favourable mid to upper level environment. While that is happening, a shearline will make its entrance during the late night hours generating occasionally cloudy skies, scattered showers and possible isolated thunderstorms across Barbados and the region. Following in its wake, a surface to mid level ridge pattern extending from a high pressure system with its center near 30N 52W will gradually build across the region. As a result, surface winds are expected to increase possibly around 20 knots thus generating the breezy conditions.
Wednesday: The surface to mid level Atlantic high pressure system will be dominant across the region. Conditions will gradually improve across the region as surface to mid level moisture along with the above mentioned shearline continues to gradually decrease while moving further westward and away from the island chain. There will be a progressive increase in the pressure gradient as the high pressure continues to build. Thus fair to partly cloudy and windy conditions are anticipated. Some weak upper level diffluence will remain across the Windwards however as surface to low level conditions gradually become more dry and stable, the chances of significant convective activity occurring will be further diminished.
Thursday: The surface to mid level high pressure system will remain dominant generating fair to partly cloudy and windy conditions with a few showers mainly over the northern Leewards due to some low level confluence .
Friday: Little change is expected across the region as the central Atlantic high pressure system continues to maintain its presence. Weak low level confluence on the southwest fringes of the above mentioned feature will continue to initiate a few showers across the Leewards and the northern Windwards.
Saturday: The surface to mid level high pressure system remains in full control of the weather pattern across the Eastern Caribbean apart from an area of low level confluence which will trigger some cloudiness and brief showers across the northern half of the region. Barbados will be on the southern fringe of this activity hence some brief showers are likely as the day progresses.
Tonight : The surface to mid level western Atlantic high pressure system will remain the dominant feature across the basin. The exception will be across the Greater Antilles from Hispaniola eastwards to Puerto Rico and the Virgin Islands as elevated moisture ahead of the weakening area of disturbed weather will spread some scattered showers and a few isolated thunderstorms . Significant activity will be supported by a nearby mid to upper level low with its center near 16N 68W.
Wednesday: Not much change from the previous days is expected across the western Caribbean during the day time. The area of disturbed weather will continue on its west north-westward motion just to the north of Hispaniola and Puerto Rico with activity associated with this feature reaching the southern most Bahamas by nightfall. A trough emanating from the center of this system will affect Hispaniola, with a speed convergent line bringing some convection to Puerto Rico and the Virgin islands. At the same time, an easterly moving frontal system in the Gulf of Mexico will bring some convection across the Yucatan Peninsula and the western most parts of Cuba.
Thursday: Model data is indicating that the area of disturbed weather will continue to to move west north-westward generating some showers across the Bahamas . The aforementioned trough will continue to generate some showers across the central Caribbean. Surface to low level moisture convergence on the south western periphery of a building Atlantic high pressure system will facilitate some shower development across the eastern Caribbean Sea. Meanwhile over the far western Caribbean, moisture pushing southward from a frontal system will continue to generate some showers across the Florida Panhandle southwestwards to the Yucatan Peninsula.
Friday: As the central Atlantic high pressure system continues to build across the eastern section of the Greater Antilles, a surface to low level confluent pattern will bring occasional cloudiness along with brief showers to Puerto Rico and the Virgin islands. Meanwhile the area of disturbed weather is expected to move northwards away from the Bahamas. The surface to low level trough trailing from the abovementioned feature will gradually traverse the central Caribbean. No significant change is expected over the western Caribbean.
Saturday: Not much change is anticipated across Puerto Rico and the Virgin Islands, westwards to Hispaniola as low level confluence on the southwestern fringe of the central Atlantic High pressure system will maintain occasionally cloudy skies and brief shower activity. Further to the west, residual moisture from a frontal system will generate some showers across western Cuba, the Yucatan and Honduras.