The Saint Lucia Meteorological Services has issued a flooding and landslides advisory for residents and motorists in areas prone to such occurrences.
In its Thursday weather forecast, the Met Office urged vigilance.
The forecast also advised small craft operators and sea bathers to exercise caution from Thursday night due to locally rough seas.
It stated that moisture and instability associated with a trough system over the Eastern Caribbean and the Inter-Tropical Convergence Zone will continue to cause cloudiness, scattered showers and isolated thunderstorms over the region during the 24-hour forecast period.
Another surface trough located over the western Tropical Atlantic is drifting slowly westward.
That weather system should affect the region from Friday into Saturday.
However, the forecast did not expect Tropical cyclone formation over the tropical Atlantic during the next seven days.