Welcome Showers Kick Off A Breezy And (Mostly) Dry Week

A weak low-level trough is traversing the Windward Islands and Trinidad and Tobago, bringing widely scattered showers accompanied by occasional gusts. As the week progresses, mostly dry and breezy conditions are set to return, barring the odd shower and cloudy periods. This may change again over the weekend.

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 10 millimeters of rainfall, with areas of northern and eastern Trinidad, as well as Tobago, accumulating up to 15 millimeters. In isolated areas, up to 30 millimeters are forecast, with most of this rainfall occurring between Monday and Tuesday.
— Saharan Dust: Little to no Saharan Dust is forecast over the next five days.
— Hazards: The main hazards, primarily through Wednesday, will originate from the odd heavy shower that will be accompanied by gusty winds that may occasionally exceed 45 KM/H. Though the threat remains low, there is the possibility of short-lived street flooding across northern Trinidad on Monday and less so on Tuesday.
— Marine: Seas are forecast to be moderate, 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

The Trinidad and Tobago Meteorological Service (TTMS) has discontinued the Adverse Weather Alert for Trinidad and Tobago. — What has happened: Fast-moving showers and thunderstorms affected…

Trinidad and Tobago is NOT under any tropical storm or hurricane threat, watch, or warning at this time.

The Forecast

Monday

Monday
2 10 0 1
Variably cloudy day with occasional showers. One or two showers may become heavy during the late morning through afternoon period. Rainfall to generally favor northern and eastern areas of Trinidad and across Tobago. Conditions to settle by the late afternoon across both islands, with a mostly settled night, barring the odd shower favoring northern areas of both islands.
Variably cloudy day with occasional showers. One or two showers may become heavy during the late morning through afternoon period. Rainfall to generally favor northern and eastern areas of Trinidad and across Tobago. Conditions to settle by the late afternoon across both islands, with a mostly settled night, barring the odd shower favoring northern areas of both islands.
2/10
Thunderstorm Chances
Very Low – Low

Tuesday

Tuesday
1 10 0 1
Mostly sunny, breezy and warm day with few cloudy periods across Trinidad. Occasional cloudy periods with showers to interrupt mostly sunny skies across Tobago, with an increase in showers across Tobago after nightfall. Trinidad to remain mostly settled into the evening, with isolated showers favoring northern and eastern areas nearing midnight.
Mostly sunny, breezy and warm day with few cloudy periods across Trinidad. Occasional cloudy periods with showers to interrupt mostly sunny skies across Tobago, with an increase in showers across Tobago after nightfall. Trinidad to remain mostly settled into the evening, with isolated showers favoring northern and eastern areas nearing midnight.
1/10
Thunderstorm Chances iThunderstorms not expected.
Very Low

Wednesday

Wednesday
1 10 0 1
Mostly sunny, breezy and warm day with the odd shower or two favoring eastern areas of Trinidad, weakening as they move westward. A mostly clear and cool night.
Mostly sunny, breezy and warm day with the odd shower or two favoring eastern areas of Trinidad, weakening as they move westward. A mostly clear and cool night.
1/10
Thunderstorm Chances iThunderstorms not expected.
Very Low

Thursday

Thursday
1 10 0 1
A misty, clear and cool morning giving way to a breezy, sunny and warm day across both islands. There is a very low chance of an odd shower.
A misty, clear and cool morning giving way to a breezy, sunny and warm day across both islands. There is a very low chance of an odd shower.
1/10
Thunderstorm Chances iThunderstorms not expected.
Very Low

Friday

Friday
1 10 0 1
A misty, clear and cool morning giving way to a breezy, sunny and warm day across both islands. There is a very low chance of an odd shower during the day. After nightfall, an increase in cloudiness with showers/rain possible, favoring Tobago initially, then Trinidad after midnight.
A misty, clear and cool morning giving way to a breezy, sunny and warm day across both islands. There is a very low chance of an odd shower during the day. After nightfall, an increase in cloudiness with showers/rain possible, favoring Tobago initially, then Trinidad after midnight.
1/10
Thunderstorm Chances iThunderstorms not expected.
Very Low

Marine Forecast

Temperatures

Monday

Low: 23-25°C

High: 29-31°C

Tuesday

Low: 22-24°C

High: 30-32.5°C

Wednesday

Low: 23-25°C

High: 30-32.5°C

Thursday

Low: 21-23°C

High: 30-32.5°C

Friday

Low: 20-22°C

High: 30-32.5°C

Cloud cover on Monday will keep minimum temperatures above seasonal averages but maximum high temperatures below average. As the week progresses, a drier airmass will lead to cooler nighttime temperatures with warm daytime maximum highs. The heat index is forecast to range between 33°C and 36°C, particularly from Tuesday.

Forecast Impacts

Flooding

Flooding
2 10 0 1
Over the next five days, across most areas of Trinidad and Tobago, most areas are set to receive between 0 and 10 millimeters of rainfall, with areas of northern and eastern Trinidad, as well as Tobago, accumulating up to 15 millimeters. In isolated areas, up to 30 millimeters are forecast, with most of this rainfall occurring between Monday and Tuesday. With the possibility of isolated heavy rainfall in localized areas of northern Trinidad on Monday and less so on Tuesday, there is a very low to low chance of street/flash flooding on both days. From Wednesday through Friday, street/flash flooding is not expected.
Over the next five days, across most areas of Trinidad and Tobago, most areas are set to receive between 0 and 10 millimeters of rainfall, with areas of northern and eastern Trinidad, as well as Tobago, accumulating up to 15 millimeters. In isolated areas, up to 30 millimeters are forecast, with most of this rainfall occurring between Monday and Tuesday. With the possibility of isolated heavy rainfall in localized areas of northern Trinidad on Monday and less so on Tuesday, there is a very low to low chance of street/flash flooding on both days. From Wednesday through Friday, street/flash flooding is not expected.
2/10
Likelihood
Very Low – Low

Forecast Rainfall Totals

  • Monday: Across the southern half of Trinidad, less than 5 millimeters. Across the northern half of Trinidad and across Tobago, between 5 and 15 millimeters of rainfall with isolated areas of up to 25 millimeters.
  • Tuesday: Little to no rainfall across the country, with isolated totals up to 5 millimeters across northern and eastern coastal Trinidad.
  • Wednesday: Little to no rainfall across the country, with isolated totals up to 5 millimeters across northern and eastern coastal Trinidad.
  • Thursday: Little to no rainfall across the country with trace accumulations.
  • Friday: Little to no rainfall across T&T, with isolated totals up to 5 millimeters favoring Tobago and northern coastal Trinidad (mainly from nightfall on Friday evening onward).

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 Thunderstorms
1 10 0 1
Strong thunderstorms are not forecast. There is a very low chance of a brief, isolated thunderstorm on Monday.
Strong thunderstorms are not forecast. There is a very low chance of a brief, isolated thunderstorm on Monday.
1/10
Likelihood
Very Low
What 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 Winds
4 10 0 1
Mid-level to low-level winds are forecast to remain relatively elevated through mid-week, which can translate to the surface in showers and thunderstorms. As a result, sustained winds are forecast to reach as high as 35 KM/H, and even higher in showers with gusts occasionally exceeding 45 KM/H. Peak winds and gusts are forecast on Monday.
Mid-level to low-level winds are forecast to remain relatively elevated through mid-week, which can translate to the surface in showers and thunderstorms. As a result, sustained winds are forecast to reach as high as 35 KM/H, and even higher in showers with gusts occasionally exceeding 45 KM/H. Peak winds and gusts are forecast on Monday.
4/10
Likelihood
Low – Medium

With winds gusting to 45 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

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 Monday, with highly isolated rainfall through the remainder of the week.

Forecast Discussion

A weak low-level trough is moving across Trinidad and Tobago on Monday with ample surface to low-level moisture, sufficient low-level convergence and confluence to produce cloudy periods with isolated to scattered showers. The atmosphere generally remains dry from the low to upper levels of the atmosphere with strong westerly shear, limiting persisting rainfall or strong convection; hence, convection will remain quite shallow.

However, peak low-level instability, based on model guidance, is forecast during the late morning through afternoon, which can lead to isolated heavy rainfall, particularly along the northern half of Trinidad, western Tobago and, to a lesser extent, western coastal Trinidad.

By Tuesday, stability increases across T&T with a drier air mass temporarily moving in and a west Atlantic high-pressure system re-establishing itself over the area. This will lead to mostly clear and cool nights and warm days, with winds generally coming from the northeast to east-southeast.

From Friday evening, models indicate a robust shearline (weakening cold front) sagging southward across the central and southern Windwards toward Trinidad and Tobago. This increase in instability and surface to low-level moisture will lead to an increase in cloudiness and rainfall by nightfall on Friday across Tobago initially, then Trinidad into Saturday.

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.

Trinidad and Tobago is still officially in the Wet Season, but many of the characteristics needed to declare the 2024 Dry Season are being met. Namely, a reduction of rainfall, the prevalence of westerly upper-level winds, the North Atlantic sub-tropical high-pressure system prevailing across the region, and a stronger, persisting trade wind inversion.

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