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: 20180422 PERIOD: Morning
During the night we recorded partly cloudy to cloudy skies at times with a few scattered showers. Satellite photos continued to display some large patches and bands of low level cloud moving towards the region. Model data also continues to show a series of embedded low level troughs moving towards the region. There was a marginal weakening of the eastern Atlantic high pressure cell, but it is still responsible for the transporting of those above mentioned patches and bands of low level cloud migrating into the region. up to 6:00am we recorded( 1.8mm) of rainfall here at Charnocks. From St Vincent northward similar conditions were recorded, while Grenada , Trinidad and Tobago reported generally fair skies.
The Guianas recorded cloudy to overcast skies with a few showers. and some light rain.
Winds across the region ranging between 12 to 17 knots. Seas were moderate to rough in open water peaking to 2.0m.
Generally fair skies with a few passing showers were recorded over Puerto Rico and the Virgin Islands during the night. Some patches of low level cloud moving over the area generated little or no precipitation. The Dominican Republic reported some intervals of weak convective activity.
Sunday: Another weak surface to low level trough will maintain instability across the island chain. Thus occasional showers and cloudiness remain the overall weather pattern across the chain. Over the northern portions of the region, the upper level environment is expected to become increasingly favorable for enhancing convection due to the presence of jet moving into the area. This coupled with some mid level moisture, will offer support in enhancing ongoing showers mainly across the northern portions of the region.
Monday: Upper level instability will increase as the jet sits mainly across the northern portions of the region. This feature will help to amplify the instability associated with the weak surface to low level trough traversing the region. Model data is indicating that weather conditions will deteriorate considerably across the Leewards and northern Windwards. This will equate to heavy prolonged periods of moderate to heavy showers and/or rain over the aforementioned areas. Barbados and the southern Windwards will be on the southern fringe of this activity, nevertheless some scattered shower activity remains likely.
Tuesday: The axis of the upper level trough will be near or over Puerto Rico, resulting in the divergent side being over the northern islands. However, around this time, model data is indicating a gradual reduction in low level moisture and instability as the surface to low level trough progresses further westward over the central Caribbean. Another surface to low level trough will draw closer to the region well beyond midnight but by this time the axis of the upper level trough would have moved further eastward, leaving the diffluent pattern to the east of the northern islands hence some gradual improvement is anticipated.
Wednesday: The axis of the upper level trough will continue on its eastward motion away from the island chain. The weak surface to low level trough (from Tuesday night) will traverse the island chain initiating a few brief showers across the region.
Sunday: The surface high pressure across the central Atlantic will continue to dominate the local area through the rest of the weekend. Small patches of low level moisture will move across the region from time to time during the day. An increase in low level moisture is expected. The potential for some afternoon localised action over the central and western Puerto Rico is high . Upper level trough will dominate the western Atlantic .
Monday: As the favorable side of the upper level trough shifts eastward across the eastern Caribbean, some improvement is anticipated across the central Caribbean. However a few weak low level troughs exiting the eastern Caribbean may bring a few showers across those islands. Farther west, as the frontal boundary slowly drifts eastward, convection remains likely across the western Caribbean. Enhanced activity will remain likely across the northern Bahamas as an area of upper level diffluence sits across the area.
Tuesday: A high pressure system will gradually build across the central caribbean however interrupted by a weak low level trough exiting the eastern Caribbean which will continue to generate occasional shower activity. The frontal system will continue to generate some some showers across the western Caribbean and the Bahamas. More so over the Bahamas, as the upper level diffluent pattern remains anchored across the area enhancing convective activity.
Wednesday: A high pressure system will gradually build across the central Caribbean. However as the frontal system drifts further eastward, shower activity will be likely across, Cuba, the Yucatan Peninsula and Jamaica. Some relief is likely across the northern Bahamas islands as the diffluent upper level pattern shifts north of the area.