While a weak low-level trough will bring some showers and isolated thunderstorms today (Tuesday), a mostly hot and sunny week is forecast with isolated afternoon rainfall bringing needed heat relief, predominantly across the western and northern areas of both islands.
What you need to know
— Rainfall: Over the next five days, between 10 and 20 millimeters are forecast across Trinidad and Tobago. In isolated areas across Trinidad, locally higher amounts are possible, particularly in isolated heavy afternoon showers or thunderstorms where daily rainfall accumulations could exceed 25 millimeters.
— Saharan Dust: Moderate Saharan Dust on Tuesday is forecast to gradually diminish through the forecast period.
— Hazards: Over the next five days, mainly in the vicinity of isolated showers and thunderstorms, the main hazards will be highly localized street/flash flooding and gusty winds up to 45 KM/H. Stronger wind gusts are likely in showers or thunderstorms on Saturday. From Wednesday, hot temperatures are forecast to return to T&T, with the hottest days expected on Friday through Sunday.
— Marine: Seas are forecast to be slight to moderate, with waves in open waters generally reaching as high as 1.5 meters through Friday and 2.0 meters by Saturday, while in sheltered areas, waves are forecast to be near to below 1.0 meter, but choppy in heavy showers/thunderstorms and along northern coasts due to long-period swells.
Latest Alerts
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
Tuesday
TuesdayWednesday
WednesdayThursday
ThursdayFriday
FridaySaturday
SaturdayMarine Forecast
Seas Forecast: Moderate Seas, Reduced Visibility
Temperatures
Tuesday
Low: 24-26°C
High: 29-32°C
Wednesday
Low: 25-27°C
High: 32-35°C
Thursday
Low: 25-27°C
High: 32-35°C
Friday
Low: 26-28°C
High: 32-37°C
Saturday
Low: 25-28°C
High: 32-37°C
The heat index on Tuesday is forecast to reach as high as 42°C, particularly in urbanized areas. From Wednesday, the heat index could reach as high as 52°C, particularly in developed and urbanized areas, ranging between 35°C and 52°C into the weekend. Note that while hot temperatures are explicitly forecast, pop-up showers/thunderstorms could keep the actual temperature lower than forecast while the heat index remains high. Heat indices above 42°C are dangerous.
Forecast Impacts
Flooding
FloodingForecast Rainfall Totals
- Tuesday: Between 10 and 25 millimeters across T&T, with isolated higher totals in heavy showers/strong thunderstorms where amounts can exceed 35 millimeters.
- Wednesday: Isolated totals nearing 10 millimeters across the western and northern areas of both islands. In thunderstorm activity, locally, higher totals are possible.
- Thursday: Little to no rainfall across the country, with isolated totals nearing 10 millimeters across western and hilly areas of both islands. In thunderstorm activity, locally higher totals are possible.
- Friday: Little to no rainfall across the country, with isolated totals nearing 10 millimeters across the western and northern areas of both islands. In thunderstorm activity, locally higher totals are possible.
- Saturday: Little to no rainfall across the country, with isolated totals nearing 10 millimeters across the western and northern areas of both islands. In thunderstorm activity, locally higher totals are possible.
Understanding Rainfall Rates
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 WindsPossible impacts include localized wind damage to trees, power lines, and small structures. Small potted plants may blow over with light outdoor objects, becoming airborne in stronger gusts. Tents may jump.
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.
The highest rainfall chances are on Tuesday with scattered activity. Thereafter, isolated rainfall is forecast and generally across the northern and western halves of both islands.
Forecast Discussion
Tropical Update
Tropical Update: All Eyes On Invest 94L
On Tuesday, an embedded low-level trough within the Intertropical Convergence Zone is forecast to move across Trinidad and Tobago. Convergence and confluence behind the trough axis will maintain unsettled conditions across T&T through Tuesday afternoon as favorable low-level convergence and deep, tropical moisture are present.
By Tuesday evening, a weak ridge will return to the area with decreasing moisture and instability.
On Wednesday through Friday, though this weak ridge remains present, with light winds, sufficient daytime heating, and sea breeze convergence, late morning through afternoon showers and isolated thunderstorms are forecast under a relatively low-shear environment and weak steering currents. The result also means where showers/thunderstorms form, the downpours may not move quickly, leading to highly localized high rainfall accumulations while most of the country remains dry.
On Friday, what is now classed as Invest 95L as of Tuesday morning is forecast to become a strengthening tropical cyclone passing safely north of the Lesser Antilles based on 00Z and 06Z Tuesday model runs. This potentially powerful tropical cyclone is forecast to influence the wind regime across T&T, and with a 1012-1016 millibar high-pressure ridge across northern South America, strong low-level southeasterly winds are forecast to develop across the Windwards as a result of the pressure difference through Monday, with peak winds expected on Saturday.
As a result, on Friday, the transition from light to near calm winds, then to increasingly stronger southeasterly winds as the day progresses, will lead to local climate effects acting as triggers for shower/thunderstorm development along western/northern Trinidad and then moving northwest. Orographic effects could enhance shower/thunderstorm activity, and as winds turn clockwise with height, funnel clouds are possible. However, the atmosphere is forecast to be dry, limiting any development of widespread showers/thunderstorms.
On Saturday, with an even drier atmosphere and stronger winds, rainfall chances are lowered, with faster-moving showers/thunderstorms if they form. However, with stronger low-level winds, in showers, these winds can make it to the surface, creating a gusty wind threat.
