A tropical wave is set to be followed by a significant surge of Saharan Dust, and rainfall chances will increase once more toward the end of the week.
What you need to know
— Rainfall: Over the next five days, overall rainfall accumulations across the country are forecast to range from 25 to 75 millimeters. Across western and eastern coastal areas, isolated higher totals.
— Saharan Dust: A significant surge of Saharan Dust is forecast from Monday evening.
— Hazards: Over the next five days, the main hazards will be localized street/flash flooding in heavy showers/thunderstorms, which may be accompanied by gusty winds up to 55 KM/H, as well as lightning in thunderstorm activity.
— Marine: Seas are forecast to be slight to moderate over the next five days, with waves in open waters generally up to 1.5 meters, and occasionally up to 2.0 meters from Wednesday. In sheltered areas, waves are forecast to be below 1.0 meter and choppy in showers/rain and thunderstorms.
Latest Alert
Adverse Weather 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
Monday
MondayTuesday
TuesdayWednesday
WednesdayThursday
ThursdayFriday
FridayMarine Forecast
Sea Forecast: Increasing Winds To Agitate Seas Into Weekend
Temperatures
Monday
Low: 25-27°C
High: 31-33°C
Tuesday
Low: 26-28°C
High: 32-34°C
Wednesday
Low: 26-28°C
High: 32-34°C
Thursday
Low: 25-27°C
High: 31-33°C
Friday
Low: 26-28°C
High: 31-33°C
Forecast Impacts
Flooding
FloodingForecast Rainfall Totals
- Monday: Across the country, less than 5 millimeters are forecast, with isolated totals up to 15 millimeters, favoring eastern and western coastal areas.
- Tuesday: Across the country, less than 5 millimeters are forecast, with isolated totals up to 15 millimeters, favoring eastern and southern areas.
- Wednesday: Across the country, less than 5 millimeters are forecast, with isolated totals up to 15 millimeters, favoring eastern areas.
- Thursday: Across the country, less than 10 millimeters are forecast, with isolated totals up to 15 millimeters, favoring eastern and southern areas.
- Friday: Across the country, less than 5 millimeters are forecast, with isolated totals up to 15 millimeters, favoring 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 50 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.
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.
Isolated rainfall is forecast throughout the week.
Forecast Discussion
Tropical Update
Tropical Update: Tracking Two Tropical Waves, Area of Interest East of Lesser Antilles
The 10th tropical wave analyzed by the National Hurricane Center is located approximately 312 nautical miles or 600 kilometers east of Trinidad and Tobago, along 55/56W, and moving west at 5-15 knots (9-28 KM/H). The tropical wave is producing scattered showers and thunderstorms, mainly associated with the confluence of trade winds occurring along the northern portion of the wave axis and then where the wave interacts with the Intertropical Convergence Zone.
Across the wave axis, total precipitable water (TPW) values, which measure atmospheric moisture, are high, between 2 and 3 inches. An upper-level trough axis is positioned across the Lesser Antilles, with favourable upper-level divergence across T&T and east of the Windwards. As a result, strong westerly to southwesterly wind shear is across Trinidad and Tobago, but any shower/thunderstorm activity across the country will see some local enhancement.
Forecast models show little to no accumulating rainfall across most areas of Trinidad and Tobago, with isolated totals up to 25 millimeters, favoring northern and eastern areas, as well as southwestern Trinidad through Tuesday morning.
On Tuesday, while significant Saharan Dust is moving into the area, the ITCZ is forecast to remain just south of Trinidad. The low-level environment will remain fairly moist, supporting isolated shower/thunderstorm activity before a high-pressure ridge rebuilds by the evening.
This ridge is forecast to remain in place across Trinidad and Tobago on Wednesday, leading to mostly dry, hazy and breezy conditions.
However, a low-level trough is forecast to develop within the ITCZ and is forecast to move across the region, bringing rainfall across the country once more from Thursday.
While localized, short-lived flooding is possible in isolated heavy showers/thunderstorms, flooding across the country has been sparse due to very dry soils. As a result, riverine flood chances remain low at this time.
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.
