St. Kitts and Nevis Meteorological Forecast

The weather forecast for the period until 8:00 p.m. on Sunday, September 21, 2025, predicts a transition from relatively stable atmospheric conditions tonight to an increased likelihood of showers and thunderstorms tomorrow. Tonight, the forecast calls for mostly fair and cool conditions, providing a pleasant respite before the anticipated change in weather patterns.

As we move into Sunday, the atmospheric dynamics shift. A weak line of moisture is expected to interact with light southeasterly winds and daytime heating, creating favorable conditions for the development of localized showers and thunderstorms. While the initial part of the day may appear partly sunny, cloud cover is expected to increase as the day progresses, culminating in a 70% chance of localized showers. This increased moisture and atmospheric instability also brings a moderate chance of isolated thunderstorms developing during the day. The combination of these factors suggests a shift from the tranquil conditions of Saturday night to a potentially more active weather scenario on Sunday.

The forecast further indicates a slight risk of isolated severe weather associated with these thunderstorms. While the majority of the activity is expected to be localized showers, the potential for severe weather underscores the need for residents to remain vigilant and stay updated on weather advisories. Severe weather can manifest in various forms, including strong winds, heavy downpours, hail, and potentially even tornadoes, though the likelihood of the latter is typically lower in these types of weather systems. The specific nature and location of any severe weather will depend on the precise development and track of the thunderstorms.

Wind conditions are expected to be generally light throughout the forecast period. East-southeasterly winds at 7–19 km/h (5–12 mph) are predicted, with a transition to variable and calm winds anticipated overnight. This relatively calm wind regime suggests that wind-related hazards are unlikely to be a significant concern. However, localized gusts associated with thunderstorms could potentially exceed these speeds, particularly during the afternoon hours when atmospheric instability is expected to peak.

Sea conditions are predicted to be moderate, with wave heights ranging from 1 to 1.5 meters (3 to 5 feet). These conditions suggest relatively calm seas, suitable for most marine activities. However, it’s important to note that localized areas of rougher seas could develop in association with thunderstorms, particularly if they become severe. Boaters and other marine users should monitor weather conditions closely and exercise caution if venturing out on Sunday, especially in the afternoon.

Overall, the forecast points towards a shift from fair and cool conditions tonight to an increased likelihood of showers and thunderstorms tomorrow. While severe weather is not guaranteed, the potential exists, and precautions should be taken. The relatively calm wind and sea conditions are expected to prevail, barring any localized disturbances associated with thunderstorm activity. Staying informed about weather updates will be crucial for planning outdoor activities and ensuring personal safety throughout the forecast period. The sunrise on Sunday is scheduled for 6:01 a.m., while sunset is expected at 6:08 p.m., providing approximately 12 hours of daylight.