Tropical waves and a low-level trough are forecast to bring increased rainfall to Trinidad and Tobago.
What you need to know
— Rainfall: Over the next five days, rainfall accumulations will vary between 25 and 75 millimeters across both islands. Across eastern and southern areas of Trinidad, eastern Tobago, and western coastal Trinidad, totals may near 150 millimeters. In highly isolated areas, totals could exceed 150 millimeters over the five-day period in the above-mentioned areas. The heaviest rainfall days are expected on Sunday and Thursday due to the passages of a low-level trough, back-to-back tropical waves, improving wind shear, and ample tropical moisture.
— Saharan Dust: A surge of Saharan Dust is forecast to return to the area from Wednesday, but higher concentrations are forecast from Thursday evening.
— Hazards: Over the next five days, street/flash flooding and gusty winds are forecast to be the main hazards near-daily. In and ahead of heavy showers or thunderstorms, wind gusts are likely to exceed 45 KM/H. There is the potential for landslides in elevated areas, particularly as the week progresses. Smaller streams across the southern and eastern halves of Trinidad will need to be monitored closely as the week progresses due to projected high 5-day rainfall accumulations.
— Marine: Seas are forecast to be moderate in open waters, with waves up to 2.0 meters and below 0.5 meters in sheltered areas. Seas may become locally choppy or rough in heavy showers or thunderstorms.
Latest Alerts
Riverine Flood Alert Discontinued For South Trinidad
Trinidad and Tobago is NOT under any tropical storm or hurricane threat, watch, or warning at this time.
The Forecast
Sunday
SundayMonday
MondayTuesday
TuesdayWednesday
WednesdayThursday
ThursdayMarine Forecast
Sea Forecast: Increasing Winds To Agitate Seas Into Weekend
Temperatures
Generally, over the next five days, maximum highs and minimum lows are forecast to be below average due to increased cloud cover.
Saturday through Wednesday
Low: 24-27°C
High: 27-30°C
Maximum high temperatures are forecast to range between 27°C to 30°C, trending cooler on Sunday and Thursday and higher across urbanized areas of Trinidad, where in built-up areas, maximum high temperatures could exceed 30°C. Overall hotter days are forecast on Monday and Tuesday. Minimum lows are forecast to remain mild, ranging between 24°C and 27°C in Trinidad and Tobago, trending cooler in interior areas. The heat index will generally be near or below 34°C.
Forecast Impacts
Flooding
FloodingForecast Rainfall Totals
- Sunday: Between 10 and 25 millimeters across both islands, with higher accumulations favoring the southern half of Trinidad. Across southern and isolated areas of central Trinidad, rainfall totals are forecast to range between 25 and 50 millimeters, with localized totals exceeding the 50-millimeter mark. The highest chances for highest rainfall accumulations favor southern and eastern coastal areas. The chances for flooding are high.
- Monday: Between 5 and 10 millimeters across both islands, with totals trending higher across eastern and southern areas of Trinidad, ranging between 10 and 25 millimeters. For Tobago, rainfall totals are forecast to range between 5 and 15 millimeters.
- Tuesday: Between 5 and 15 millimeters of rainfall across both islands, with totals nearing 25 millimeters across the eastern half of Trinidad, as well as localized areas of western Trinidad where thunderstorms occur. In isolated areas, totals may exceed 25 millimeters.
- Wednesday: Between 5 and 15 millimeters of rainfall across both islands, with totals nearing 25 millimeters across the eastern half of Trinidad and across Tobago, as well as localized areas of western Trinidad where thunderstorms occur. In isolated areas, totals may exceed 25 millimeters.
- Thursday: Between 10 and 25 millimeters across both islands, with higher accumulations favoring the eastern halves of Trinidad and Tobago, where totals can near 30 millimeters. In isolated areas, 24-hour rainfall totals may exceed 40 millimeters, particularly across Tobago, eastern and northern Trinidad. The chances for flooding are very high.
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
Short-Lived Saharan Dust Surge From Thursday into Weekend
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.
Through the next five days, isolated to scattered rainfall is forecast across Trinidad and Tobago.
Forecast Discussion
Tropical Update
Tropical Update: Atlantic Remains Quiet, Tropical Wave To Bring Rainfall To T&T
A low-level trough is forecast to move across Trinidad and Tobago on Sunday. This trough is forecast to move through an environment with favorable low and mid-level convergence, upper-level divergence, low wind shear, and sufficient low-level moisture for showers and thunderstorms. However, these showers and thunderstorms are forecast to be quite fast-moving, up to 25 knots (46 KM/H) from the southeast. The result – fast moving showers and thunderstorms with brief but heavy rainfall and higher rainfall accumulations across southern and eastern areas.
High levels of moisture will linger on Monday, but the low-level environment is not forecast to be as favorable as Sunday. Still, ample instability and favorable low-level convergence will support shower and thunderstorm development through the first half of the day. Winds are set to decrease slightly on Monday into Tuesday, leading to somewhat slower-moving showers and thunderstorms, which could result in locally higher rainfall totals.
By nightfall on Monday, Tropical Wave 11 is forecast to near the country, moving across the islands on Tuesday, increasing atmospheric moisture once again with sufficient instability present to support convection throughout the day.
On Wednesday, conditions are set to be the typical wet season day, with sunny skies to kick off the day, then localized climatic effects (sea-breeze convergence, daytime heating, and orographic convergence) will result in the usual late morning through afternoon showers along coastal and hilly areas. Model guidance indicates a risk for strong thunderstorms southeast of Trinidad, generally remaining offshore Wednesday evening, as Tropical Wave 12 nears.
Forecast models indicate a favorable atmosphere for fast-moving heavy showers and thunderstorms, with an elevated risk of gusty winds on Wednesday night through Thursday with Tropical Wave 12’s passage. Additionally, upper-level divergence is forecast to be quite favorable for the development of heavier showers and thunderstorms. However, wind shear is forecast to be moderate to strong from the northwest, keeping overall heavier rainfall east of Trinidad and Tobago. Still, this is forecast to be a particularly wet day for the country, with more widespread rainfall compared to Sunday, where the heaviest rains are set to favor southern Trinidad.
The wild card, as it tends to be, will be the role Saharan Dust plays in reducing rainfall. Dust models indicate Saharan Dust increasing from Wednesday at mild concentrations, with moderate concentrations from Thursday. In the past, numerical weather prediction models do not accurately take into consideration the role of Saharan Dust in limiting showers and thunderstorms from forming. Given that this is closer to the end of the forecast period, we have some time to wait and see how models evolve.
Regardless, from Sunday through Thursday, total precipitable water, a measure of atmospheric moisture, is forecast to be above 2.0 inches (50+mm), while 850-300 millibar relative humidity fluctuates between 55% and 70% – ample moisture to support showers and thunderstorms across the country.
Given we are set to see days with 25 millimeters or more of rain accumulating in particular areas, repeated days with this level of rainfall in the same areas undoubtedly raise flooding concerns and landslide concerns in elevated areas. Though there are no alerts, watches, or warnings in effect as of Saturday night, if you live in flood-prone areas, ensure that you are ready for the upcoming wet period and overall for the Wet Season and 2023 Atlantic Hurricane Season.
