A series of low-level to surface troughs are forecast to move across Trinidad, Tobago, and the Windward Islands through the end of the week, bringing periods of rain, heavy showers, and thunderstorms. While heavier rainfall is forecast to remain offshore and affect eastern areas, street/flash flooding will be a concern, with gusty winds accompanying heavy/violent rainfall, particularly from Thursday.
What you need to know
— Rainfall: Over the next five days, across the western half of Trinidad, between 10 and 30 millimeters are forecast, while across the eastern half of Trinidad and Tobago, between 25 and 75 millimeters of rainfall is forecast. In isolated areas across eastern Trinidad and eastern Tobago, five-day totals approaching 100 millimeters are possible. In highly isolated heavy showers and thunderstorms, 24-hour rainfall totals could exceed 50 millimeters.
— Saharan Dust: Mild concentrations of Saharan Dust will be present through the forecast period, with rainfall tempering air quality impacts.
— Hazards: The main hazards, primarily Wednesday through Friday, will originate from periods of rain, heavy showers, and thunderstorms, producing cloud-to-ground lightning, gusty winds that may occasionally exceed 55 KM/H, and periods of heavy/violent rainfall, which can trigger street/flash flooding. In elevated areas of northern Trinidad and eastern Tobago, landslides are also possible, particularly as the weekend progresses. Elevated winds are set to continue into the weekend.
— Marine: Seas are forecast to be moderate, with waves in open waters generally reaching as high as 2.0 meters on Wednesday and getting as high as 3.0 meters into the weekend. In sheltered areas, waves are forecast to be up to 1.5 meters and choppy in heavy showers and thunderstorms and along north-facing coastlines of T&T.
Latest Alert
Hazardous Seas Alert Discontinued For T&T
Trinidad and Tobago is NOT under any tropical storm or hurricane threat, watch, or warning at this time.
The Forecast
Wednesday
WednesdayThursday
ThursdayFriday
FridaySaturday
SaturdaySunday
SundayMarine Forecast
Seas Forecast: Moderate Seas, Reduced Visibility
Temperatures
Wednesday
Low: 23-25°C
High: 29-31°C
Thursday
Low: 23-25°C
High: 29-31°C
Friday
Low: 23-25°C
High: 29-31°C
Saturday
Low: 23-25°C
High: 31-33°C
Sunday
Low: 23-25°C
High: 31-33°C
Maximum high temperatures are forecast to remain near to below-average levels for November across Trinidad and Tobago over the next three days due to forecast rainfall and cloudy skies, with actual temperatures reaching as high as 33°C across both islands, mainly by the weekend. Across the country, over the next five days, the heat index, or feels like temperature, is forecast to range between 34°C and 38°C, trending higher over the weekend. Minimum lows are forecast to range between 23°C and 26°C daily but can trend lower in interior areas of the country and across eastern Tobago, where rainfall persists.
Forecast Impacts
Flooding
FloodingForecast Rainfall Totals
- Wednesday: Across the western half of Trinidad, between 5 and 15 millimeters of rainfall. Across the eastern half of Trinidad and Tobago, between 10 and 25 millimeters of rainfall is forecast with locally higher amounts.
- Thursday: Across the western half of Trinidad, between 5 and 15 millimeters of rainfall. Across the eastern half of Trinidad and Tobago, between 10 and 25 millimeters of rainfall is forecast with locally higher amounts.
- Friday: Across Trinidad and Tobago, rainfall totals between 10 and 25 millimeters are forecast, with isolated higher totals along the western and eastern coastal areas of Trinidad.
- Saturday: Less than 5 millimeters across most of Trinidad and Tobago, with higher totals across eastern areas.
- Sunday: No rainfall forecast across the western half of Trinidad. Less than 5 millimeters across most of Trinidad and Tobago, with higher totals across eastern areas.
Understanding Rainfall Accumulations
Putting the rainfall forecast into context, rainfall rates in excess of 50 millimeters per hour or areas that receive in excess of 25 millimeters within an hour tend to trigger street flooding across the country or flash flooding in northern Trinidad. For riverine flooding to occur, a large area of the country (not just in highly localized areas of western coastal Trinidad) would have to record upwards of 75 millimeters within 24 hours, and rainfall would have to fall across major rivers’ catchment areas.
Strong Thunderstorms
Strong ThunderstormsWhat is a strong or severe thunderstorm?
Given how rare these types of thunderstorms are in our region – we classify a severe or strong thunderstorm as one that produces any of the following:
- Damaging wind gusts exceeding 55 KM/H;
- Frequent lightning (more than 30 cloud-to-ground strikes within a 10-minute period);
- Hail (of any size);
- Rainfall of more than 50 millimeters or more within an hour or exceeding 75 millimeters or more within three hours;
- The sighting of a funnel cloud or touchdown of a waterspout/tornado associated with the thunderstorm.
Gusty Winds
Gusty WindsWith winds gusting to 55 KM/H and occasionally above, whole trees can be in motion, with larger trees and weaker branches falling. Light outdoor objects can topple or become airborne, such as garbage cans, loose galvanize, construction material, and outdoor furniture. Tents may also jump. Note these impacts are mainly possible ahead of and during heavy/violent showers and thunderstorms.
Other Hazards
Saharan Dust Forecast
Major Saharan Dust Surge Now Moving Across T&T
Why I May Not/Will Not See Rainfall?
A frequent complaint is the forecast is wrong because I didn’t experience any rainfall. Scattered showers mean that you, individually, may experience some showers intermittently throughout the day, and there is a higher chance for this activity than isolated activity. Widespread showers mean that nearly all persons and areas may experience rainfall.
Isolated rainfall is forecast on Saturday, while isolated to scattered rainfall is forecast on Wednesday through Friday. Highly isolated to no rainfall is forecast on Sunday.
Forecast Discussion
On Wednesday, surface-to-low-level confluence (winds slowing down, piling up like a traffic jam, and creating an area of convergence), increasingly deep-layered moisture, and a marginally favorable upper-level pattern is forecast across T&T, with a surface-to-low-level trough east of the area, making its way westward. These features will support cloudiness with light to moderate rain, isolated to scattered showers (at times heavy), and even the odd, brief thunderstorm. Wind shear remains very strong, up to 35 knots from the west on Wednesday, then shifting from the northwest to north by Friday into Saturday. As a result, the heaviest rains are forecast to remain offshore eastern T&T, with thunderstorms and heavy showers remaining fairly weak.
By Thursday into Friday, a slightly stronger low-level trough will move across the Windwards, including T&T, bringing more cloudiness, rain, showers, and thunderstorms. Low-level winds are also forecast to increase during this period, which will cause windy conditions at the surface and stronger gusts in and ahead of showers/thunderstorms/heavy rain.
Though stronger winds are forecast to continue into the weekend, the mid and upper levels of the atmosphere are forecast to dry out, reducing cloudiness and rainfall. By Friday night, a high-pressure ridge is forecast to become the dominant weather feature across the Windwards, including T&T, and remain present across the area into next week.
Note that as an extended forecast goes further into the future, it is normal for the certainty to be reduced relative to the extended period.
