|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: 20170122 PERIOD: Evening
Mixed weather conditions prevailed across the Eastern Caribbean today. The Leewards encountered partly cloudy to occasionally cloudy skies with a few scattered showers due to a shearline extending from a dissipating stationary front trailing in the central Atlantic. While this was happening, a building high pressure system was in control of the weather conditions across the northern Windward islands. Hence, mostly fair to partly result fair to partly cloudy skies prevailed with a notable absence of shower activity.
Further south, low level convergence along the south-eastern periphery of the building high pressure system, generated some showers across Barbados and St. Vincent. Some precipitation was also observed approaching the Grenadines as the day progressed. Cloudy skies with brief showers also prevailed across Grenada and the republic of Trinidad and Tobago and this was verified by sattelite and radar imagery. Moisture levels remained confined beneath 10 000ft, as a dry and stable mid level atmosphere negated any convective activity.
Winds across the area ranged from 5 to 10 knots across the Leewards and extreme southern Windwards, whilst 10 - 15 kt winds were present across the remainder of the region. This allowed sea conditions to remain slight to moderate in open water with swells peaking to 2.0m.
As far as the Guianas were concerned, a mid to upper level trough maintained an extensive area of cloudiness and scattered showers. Some isolated thunderstorm activity was observed over Suriname during the early afternoon.
A band of low level clouds associated with a shearline trailing from a stationary frontal system in the central Atlantic, generated some cloudiness and brief scattered showers across the Virgin Islands, westwards across Puerto Rico and into the northern Caribbean Sea. Some of this cloudiness brushed the south coasts of Hispaniola during the morning hours.
Over the remainder of the westen Caribbean, generally fair skies prevailed as the Western Atlantic high pressure system continued to be the dominant feature. Some clouds were observed passing over Jamaica resulting in partly cloudy conditions there. Meanwhile, the northern coasts of Venezuela experienced some cloudiness and scattered showers and cloudy skies due to low level convergence.
Eastern Caribbean Outlook
Partly cloudy to cloudy skies with brief showers will prevail over the Leewards into Monday due to the lingering presence of the shearline. Simultaneously, the high pressure system with its center in the eastern Atlantic will continue to influence the weather conditions across the northern Windwards. Further south, some low level convergence and elevated moisture levels on the southern periphery of the high pressure system, will maintain some measure of instability across the southern Windwards. Shower activity is expected to brief however, as a dry and stable air mass is stil evident at the mid levels of the atmosphere. Model data is indicating that the high pressure system will briefly dominate weather conditions across Barbados and the Eastern Caribbean into Tuesday. Following this, a south-easterly to southerly wind flow at the lower levels will result in the northward movement of some moisture across the region thus inducing some shower activity at that time. Another deep layered low pressure system propagating eastward is likely to induce a trough across the island chain generating some instability and another round of showers across the region from as early as Wednesday. These showers will persist until late Thursday as a developing high pressure system in the western Atlantic, transports some drier and more stable air over the region.
Western Caribbean Outlook
Cloudy skies will persist across Puerto Rico and the Virgin Islands as the shearline lingers over those islands. Similiar conditions are expected across some sections of Hispaniola during the next 24 hours. Further west, the Western Atlantic high pressure system located near 24N 70W, will remain the dominant feature. Significant shower activity is expected to be minimal due to a strong subsident pattern.Further north of the region, a low pressure system is expected to exit the eastern coast of the USA by late Monday. As it migrates to the east, the trailing frontal system could provide some unsettled weather across the Bahamas abd Cuba as the week progresses.
|Meteorologist Brian Murray|