Later this evening into Tuesday, a weak surface to low level trough/easterly wave, along with the Inter Tropical Convergence Zone (ITCZ) could result in scattered showers, periods of rain and possible thunderstorm activity across the extreme Southern Windward Islands (including the Grenadines)…see image at 4:15pm above compliments RAMMB.
However, most of the shower activity is expected across Grenada, Trinidad/Tobago towards Northeast Venezuela.
Models project that the disturbed area which is to the east of island chain could become an open wave by early Tuesday. As the disturbed area edges closer to the islands, associated moisture could be supported by an upper level low and trough by late Tuesday into Wednesday resulting in scattered showers. Scattered showers could continue on Thursday as the ITCZ nudges northward creating unstable conditions. However, the axis of the area of concern should approach the islands by Friday as an easterly wave, with scattered moderate to heavy showers, periods of rain and thunderstorm activity…. Rainfall accumulations will be monitored.
Moderate trades from the east north-east can be expected overnight across mainland and northernmost Grenadines, while fresh breeze should prevail across the Grenadines. Wind speeds should generally decrease towards gentle by Wednesday afternoon while veering to east south east and moderate breeze should return during Thursday.
Barometric Pressure should range 1012mb - 1014mb, gently rising (1015mb - 1017mb) late Wednesday with a far Eastern Atlantic High Pressure cell rebuilding briefly on Thursday.
Expect slight to moderate seas with ENE swells peaking near 1.2m on west coasts and near 1.8m on east coasts. Expect NE swells by Tuesday afternoon, with a fall in wave heights to slight across SVG by Wednesday morning to range 0.6-1.2m, rising again by Thursday evening.
Occasional slight haze should continue across our islands, possibly clearing for good visibility late Thursday.