Barbados Meteorological Services
Charnocks ChCh
Weather Discussion
http://www.BarbadosWeather.org

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: 20180119 PERIOD: Evening

Brian Murray 4 Evening Fair to partly cloudy skies with a few brief showers prevailed across Barbados during the day. Similiar conditions were reported over the remainder of the island chain as the high pressure system briefly dominated the weather conditions. The leading edge of a approaching low level trough was noted on satellite imagery heading towards the central Windwards, being transported by the easterly wind flow. Radar composite analysis also showed a few echoes over the Leewards with the more prominent ones located to the west coasts of Barbados. Another band of moderate echoes were observed approaching the islands of St.Lucia and Martinique during the afternoon.

Rainfall accumulations across the islands ranged from traceable amonts to as much as 2.0mm in St.Kitts and the republic of Trinidad and Tobago. Here in Barbados, no rainfall was recorded at the Charnocks station.

Further to the south, fair to partly cloudy conditions were experienced across Trinidad, Tobago and the Guianas. A few isolated areas of moderate convection flared up along the interior districts of Suriname and French Guiana during the afternoon.

Seas remained moderate in open water peaking to 2.5m. Light winds were reported across some islands, with wind speeds peaking to 15 knots elsewhere. During the day, the southern end of a frontal boundary over the Atlantic became stationary from 24N 68W southweswards across eastern Cuba, over the southwestern Caribbean Sea to just off the coast of Nicaragua near 11N, 84W. Satellite imagery showed some scattered showers and thunderstorms still existing to the east of the front. Similar activity occurred south of 11N west of 77W being aided by a favourable upper-level diffluent flow. Northeasterly winds in the 20 to 25 kt range continue to the west of the front, The just mentioned front also generated partly cloudy to cloudy skies skies and scattered showers across Hispaniola. On the other hand, Puerto Rico and the Virgin islands remained under the influence of a high pressure system although some low level clouds linked to a low level trough traversed the northern coasts of the isla Tonight: Little change in the weather is expected as the high pressure system with its center near the Azores will remain the dominant weather feature across the island chain. In addition to this, a stable air mass at the mid and upper levels will also persist, limiting any significant shower activity. However, a weak confluent pattern across the Windward islands and the passage of a weak low level trough, will still generate a few brief showers. Showers are expected to increase during the nighttime across the central and southern Windwards, as moisture and instability levels increase due to the presence of the low level trough.

Saturday: The low level trough will make its exit from the island chain, accompanied by its cloudiness and scattered shower activity . Model data analysis is indicating that low level confluence across the south-easterly and southern periphery of the high pressure system is still likely to generate some scattered showers mainly across the central and southern portion of the region until sunset. The remainder of the island chain will be under the influence of the high pressure system with the presence of a few brief isolated showers.

Sunday: The high pressure system will remain dominant across the region, also weak low level confluence along the south easterly and southern periphery of the high pressure system will generate some low level cloud patches over the central and southern Windwards. No significant change in weather conditions from previous day is expected.

Monday: No significant change in the overall weather pattern is anticipated. Model data is indicating some low level moisture linked to a weak pulse traversing the Leewards and northern Windwards. This will trigger occasional cloudiness and brief showers over the just mentioned areas.

Tuesday: Surface to upper level ridge pattern will exists. Shallow low level cloud patches drifting in the predominantly east north-easterly trade wind flow will produce brief occasional scattered shower activity. A building high pressure system in the western Atlantic will generate bands of low level clouds on its southern fringe which will affect the Leewards.

Breezy conditions will return across the eastern Caribbean around Saturday. As the high pressure system rebuilds across the region strengthening the pressure gradient, this will lead to an increase in wind speeds, 20 to 25 knots from model analysis. Tonight: The stationary front extending from the southwestern Atlantic across eastern Cuba, southwestwards over Jamaica into the southwest Caribbean Sea will continue to generated generally cloudy skies with most of the significant showers and thunderstorms occuring east of Nicaragua . Scattered showers will occur over the Bahamas and to a lesser extent, eastern Cuba. As it journeys eastward, the Cayman islands and Hispaniola will continue to receive their share of the activity associated with the front. At the same time, an upper level Jet field will offer some convective enhancement across the just mentioned areas. Strong low level convergence and upper level diffluence will remain across central America with continued convection.

Saturday: Frontal system will journey further eastward across the central Atlantic. Showers will remain across the southern Bahamas, Cuba, Jamaica and Hispaniola following the front's passage. Favourable upper level conditions due to the presence of an upper level jet across the area, may enhance a few isolated convective cells. The low level convergent pattern and upper level diffluence will remain across central America.

Sunday:An upper level diffluent pattern will be across the western and central Caribbean basin. A mid level inverted trough and convergence across the western and south west Caribbean will maintain some convection across those areas. However, as a western Atlantic high pressure system builds in tandem with a mid level high over Puerto Rico, only a few isolated areas of enhanced convection are anticipated mainly over the southwest Caribbean basin.

Monday: No significant change is anticipated across the basin.

Tuesday: Apart from some low level convergence on the southern fringe of the western Atlantic high pressure system which will generate some cloudiness and showers over Puerto Rico westwards to the eastern Cuba, no significant change in weather pattern from previous day is anticipated across the remainder of the region.

An increase in wind speeds across the Caribbean is likely as the high pressure builds. 20 to 30 knot winds from model analysis. This will cause an agitation in sea swells mainly in the western Caribbean Sea.