Moisture will increase by this evening as instability from a strong tropical wave approaches the islands. Generally, cloudy skies and showers with the chance of isolated thunderstorms are forecast Tuesday night into Wednesday; intensifying from Wednesday afternoon into Wednesday night as this broad wave moves across Saint Vincent and the Grenadines. Model guidance is indicating approximately 35mm of rainfall accumulation by 8 o’clock Wednesday night. Showers are forecast to continue throughout the night as the wave axis crosses over the islands. A further 25mm is possible by early Thursday night as the wave moves west north-westward to affect the Northern Windward Islands.
There is another well defined tropical wave traversing the Atlantic, and based on model guidance it is likely to develop further as it crosses SVG around Friday night. Model guidance is currently forecasting intense convective activity (heavy showers and thunderstorms) into Saturday with over 2 inches of rainfall accumulation possible in a short period of time around Friday night. Winds are forecast to be NE- SE at approximately 40km/h -60km/h from Friday evening and seas are going to deteriorate, especially to the south, over the Grenadines with swells possibly peaking to 13ft or 4m. Saharan dust intrusion will be present but may have little impact on this system. The Saint Vincent Meteorological Services will monitor this wave and residents and motorists are urged to stay updated.