A shearline is set to bring cloudy periods with passing showers, accompanied by gusty winds, mainly to Tobago from Thursday evening into Friday. At the same time, mostly sunny conditions continue across most of Trinidad. As the weekend progresses, increasingly breezy to windy conditions are forecast across T&T and the remainder of the Lesser Antilles.
What you need to know
— Rainfall: Over the next five days, across most areas of Trinidad and Tobago, most areas are set to receive between 0 and 15 millimeters of rainfall, with areas of northern and eastern Trinidad, as well as Tobago, accumulating up to 25 millimeters. Most of this rainfall is forecast on Thursday night through Friday night, mainly across Tobago.
— Saharan Dust: Little to no Saharan Dust is forecast over the next five days.
— Hazards: The main hazards, primarily from Saturday, will be elevated sustained winds, up to 35 KM/H, and gusts between 45 KM/H and 55 KM/H, particularly in showers/rain. Though the threat remains low, there is the possibility of short-lived street flooding across Tobago on Thursday night through Friday.
— Marine: Seas are forecast to be moderate, becoming moderate to rough from Saturday night, with waves in open waters generally between 2.0 and 2.5 meters. In sheltered areas, waves are forecast to be up to 1.5 meters and choppy in showers.
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
Thursday
ThursdayFriday
FridaySaturday
SaturdaySunday
SundayMonday
MondayMarine Forecast
Sea Forecast: Increasing Winds To Agitate Seas Into Weekend
Temperatures
Thursday
Low: 19-24°C
High: 30-32°C
Friday
Low: 21-24°C
High: 30-31°C
Saturday
Low: 21-25°C
High: 30-32°C
Sunday
Low: 22-25°C
High: 30-32.5°C
Monday
Low: 20-24°C
High: 30-32.5°C
More information
Cool Nighttime Temperatures Forecast For T&T Tonight
Forecast Impacts
Flooding
FloodingForecast Rainfall Totals
- Thursday: Little to no rainfall across both islands, with less than 5 millimeters across Tobago, mainly from the late afternoon into the night.
- Friday: Across Trinidad, little to no rainfall, with isolated accumulations of up to 5 millimeters in northeastern areas. For Tobago, between 10 and 20 millimeters, with isolated totals up to 25 millimeters, particularly on windward-facing coasts.
- Saturday: Little to no rainfall across Trinidad, with isolated totals up to 5 millimeters across northeastern Trinidad and southwestern Tobago.
- Sunday: Little to no rainfall across the country with trace accumulations.
- Monday: Little to no rainfall across T&T, with isolated totals up to 5 millimeters eastern areas of both islands.
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.
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.
Highly isolated rainfall is forecast throughout the next five days, with isolated to scattered rainfall across Tobago on Thursday night into Friday night.
Forecast Discussion
On Wednesday night through Thursday, a dry airmass with North American origins, brought southward by a prevailing surface-to-mid-level high-pressure system, will lead to mostly clear and cool conditions across both islands.
However, a shearline north of the country will also be sagging southward on Thursday, leading to increased cloudiness with periods of rain/showers across Tobago from mid-Thursday and, to a lesser extent, northern and eastern Trinidad from Thursday night into Friday. A shearline is a line or narrow zone across which there is an abrupt change in the horizontal wind direction, which is typically accompanied by areas of low-level convergence, shallow showers/rain and cloudiness.
This shearline is forecast to weaken on Saturday, with the prevailing Atlantic high-pressure system strengthening. Low-level winds are forecast to increase from Saturday. These two features will generally dominate for the remainder of the forecast period with pockets of low-level convergence and moisture within the moderate to strong easterly trade wind flow, bringing brief cloudy periods, sharp showers with gusty winds, and generally breezy to windy conditions.
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.
