Forecast: Daily Thunderstorms, Showers To Interrupt Hot Days
Over the next five days, partly to mostly cloudy and hot mornings are forecast to be interrupted by rapidly developing late morning through afternoon showers and thunderstorms, which can become locally strong/severe from Thursday through the weekend.
What you need to know
— Rainfall: Over the next five days, through Sunday, overall rainfall accumulations across the country are forecast to range between 25 and 50 millimeters, with totals trending between 75 and 100 millimeters, favoring Trinidad. Daily, favoring Trinidad, rainfall totals exceeding 25 millimeters are likely in highly isolated areas, particularly Tuesday and Friday into Saturday.
— Saharan Dust: Through Thursday, mild to moderate Saharan Dust concentrations are likely, with little to no dust forecast through Sunday.
— Hazards: Daily, particularly from Wednesday, locally heavy rainfall is likely in heavy showers/thunderstorms, producing localized street/flash flooding. Gusty winds up to 50 KM/H, as well as frequent cloud-to-ground lightning, are also possible. Seas in the Gulf of Paria may also become locally choppy due to heavy downpours, particularly from Friday. From late morning through afternoons on Friday, funnel clouds are possible along Trinidad’s western coastal areas and the Gulf of Paria. If these funnel clouds touch down over water, they become a waterspout, and if they do over land, they become a tornado, though this is rare.
— Marine: Generally, slight seas are forecast through Sunday.
Latest Alert
Trinidad and Tobago is NOT under any tropical storm or hurricane threat, watch, or warning at this time.
The Forecast
Tuesday PM
Tuesday PM
5
10
0
1
Late afternoon showers/thunderstorms favoring southern and southwestern Trinidad, with partly to mostly cloudy skies elsewhere. A mostly settled night, with the odd shower or two favoring Tobago and eastern Trinidad.
Late afternoon showers/thunderstorms favoring southern and southwestern Trinidad, with partly to mostly cloudy skies elsewhere. A mostly settled night, with the odd shower or two favoring Tobago and eastern Trinidad.
5/10
Thunderstorm Chances
Medium
Wednesday
Wednesday
6
10
0
1
A mostly sunny day is forecast to give way to isolated thunderstorms and showers from the late morning favoring Trinidad, settling by the late afternoon. A mostly settled night across Tobago and most of Trinidad, with isolated showers/thunderstorms in the Gulf of Paria.
A mostly sunny day is forecast to give way to isolated thunderstorms and showers from the late morning favoring Trinidad, settling by the late afternoon. A mostly settled night across Tobago and most of Trinidad, with isolated showers/thunderstorms in the Gulf of Paria.
6/10
Thunderstorm Chances
Medium – High
Thursday
Thursday
7
10
0
1
Early morning showers and isolated thunderstorms are forecast from the south, moving northward in the Gulf of Paria and Columbus Channel with activity settling by daybreak. A mostly sunny and hot day, with showers and thunderstorms developing by midday, favoring Trinidad. Locally intense/severe showers and thunderstorms are possible favoring the northern and western halves of Trinidad during the early afternoon. Activity forecast to gradually diminish through the afternoon, with partly to mostly cloudy skies. By the evening and through the night, showers and thunderstorms are likely to drift off of northern Venezuela into the Gulf of Paria and Columbus Channel.
Early morning showers and isolated thunderstorms are forecast from the south, moving northward in the Gulf of Paria and Columbus Channel with activity settling by daybreak. A mostly sunny and hot day, with showers and thunderstorms developing by midday, favoring Trinidad. Locally intense/severe showers and thunderstorms are possible favoring the northern and western halves of Trinidad during the early afternoon. Activity forecast to gradually diminish through the afternoon, with partly to mostly cloudy skies. By the evening and through the night, showers and thunderstorms are likely to drift off of northern Venezuela into the Gulf of Paria and Columbus Channel.
7/10
Thunderstorm Chances
High
Scattered early morning showers and thunderstorms are forecast across both islands, settling by the mid-morning, leading to a mostly cloudy and hot day. By midday, additional showers and thunderstorms are forecast to develop favoring northern Trinidad initially, spreading across the country through the afternoon. Mist/fog may develop after nightfall, with northward moving showers/thunderstorms nearing midnight.
Scattered early morning showers and thunderstorms are forecast across both islands, settling by the mid-morning, leading to a mostly cloudy and hot day. By midday, additional showers and thunderstorms are forecast to develop favoring northern Trinidad initially, spreading across the country through the afternoon. Mist/fog may develop after nightfall, with northward moving showers/thunderstorms nearing midnight.
7/10
Thunderstorm Chances
High
Saturday
Saturday
6
10
0
1
Early morning showers and isolated thunderstorms are forecast from the south, moving northward in the Gulf of Paria and Columbus Channel. Throughout the day, variably cloudy conditions are forecast to be interrupted by rain, showers and thunderstorms. Conditions to briefly settle into the evening, with a return of showers and isolated thunderstorms are forecast from the south, moving northward in the Gulf of Paria and Columbus Channel.
Early morning showers and isolated thunderstorms are forecast from the south, moving northward in the Gulf of Paria and Columbus Channel. Throughout the day, variably cloudy conditions are forecast to be interrupted by rain, showers and thunderstorms. Conditions to briefly settle into the evening, with a return of showers and isolated thunderstorms are forecast from the south, moving northward in the Gulf of Paria and Columbus Channel.
6/10
Thunderstorm Chances
Medium – High
Early morning showers and thunderstorms to give way to a mostly hot and sunny day. By the late morning through the afternoon, scattered showers and thunderstorms moving from the south to north are forecast to develop across the country. Conditions to settle by the evening across both islands.
Early morning showers and thunderstorms to give way to a mostly hot and sunny day. By the late morning through the afternoon, scattered showers and thunderstorms moving from the south to north are forecast to develop across the country. Conditions to settle by the evening across both islands.
6/10
Thunderstorm Chances
Medium – High
Temperatures
Forecast Impacts
Flooding
Over the next five days, through Sunday, overall rainfall accumulations across the country are forecast to range between 25 and 50 millimeters, with totals trending between 75 and 100 millimeters, favoring Trinidad. Daily, favoring Trinidad, rainfall totals exceeding 25 millimeters are likely in highly isolated areas, particularly Tuesday and Friday into Saturday.
Street & Flash Flooding
Street & Flash Flooding
7
10
0
1
The chances of street/flash flooding are high, particularly across Trinidad, particularly following last few days of rainfall.
The chances of street/flash flooding are high, particularly across Trinidad, particularly following last few days of rainfall.
High
Riverine Flooding
Riverine Flooding
1
10
0
1
Based on latest overall forecast rainfall totals, the risk of riverine flooding remains very low. The heaviest rainfall is forecast to occur on Tuesday and Friday into Saturday, with the highest totals occurring during this time frame along western coastal Trinidad and eastern areas.
Based on latest overall forecast rainfall totals, the risk of riverine flooding remains very low. The heaviest rainfall is forecast to occur on Tuesday and Friday into Saturday, with the highest totals occurring during this time frame along western coastal Trinidad and eastern areas.
Very Low
Forecast Rainfall Totals
- Wednesday: Less than 10 millimeters of rainfall across the country, with isolated higher totals of up to 25 millimeters favoring western coastal and northern areas of Trinidad. Locally higher totals are possible in isolated heavy showers and thunderstorms.
- Thursday: Less than 10 millimeters of rainfall across the country, with isolated higher totals of up to 25 millimeters favoring western and southern coastal and northern areas of Trinidad. Locally higher totals are possible in isolated heavy showers and thunderstorms.
- Friday: Across Tobago, less than 5 millimeters, with rainfall totals ranging between 15 and 25 millimeters across Trinidad, with isolated higher totals across the island. Locally higher totals are possible in isolated heavy showers and thunderstorms.
- Saturday: Across both islands, between 10 and 25 millimeters of rainfall. Locally higher totals are possible in isolated heavy showers and thunderstorms.
- Sunday: Across both islands, between 10 and 25 millimeters of rainfall. Locally higher totals are possible in isolated heavy showers and thunderstorms.
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
6
10
0
1
Throughout the next five days, due anomalously light and at times westerly and southerly winds, as well as deep-layered moisture from Thursday, and light to moderate wind shear, locally strong or severe thunderstorms are possible, mainly near and after midday through the afternoon from Thursday. The main hazards will be violent rainfall rates with locally high rainfall accumulation, and frequent lightning, as well as the possibility for funnel cloud development.
Throughout the next five days, due anomalously light and at times westerly and southerly winds, as well as deep-layered moisture from Thursday, and light to moderate wind shear, locally strong or severe thunderstorms are possible, mainly near and after midday through the afternoon from Thursday. The main hazards will be violent rainfall rates with locally high rainfall accumulation, and frequent lightning, as well as the possibility for funnel cloud development.
Medium – High
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
Overall wind speeds are forecast to be light across Trinidad and Tobago, with sustained winds remaining generally below 25 KM/H. In heavy showers and thunderstorms, sustained winds can reach 35 KM/H and gusts may reach 50 KM/H.
Overall wind speeds are forecast to be light across Trinidad and Tobago, with sustained winds remaining generally below 25 KM/H. In heavy showers and thunderstorms, sustained winds can reach 35 KM/H and gusts may reach 50 KM/H.
Low – Medium
With winds gusting above 50 KM/H, 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
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.
Over the next five days, generally isolated to scattered rainfall is forecast.
Forecast Discussion
Overnight tonight through Wednesday, Tropical Wave 33 is forecast to move across Trinidad and Tobago, with most of the heavier showers and thunderstorms associated with the wave axis remaining north of the country. However, it will interact with the Intertropical Convergence Zone (ITCZ)/monsoon trough – a feature like the ITCZ, with southwesterly winds meeting northeasterly winds. As a result, showers and thunderstorms are likely during the early morning through mid-afternoon on Wednesday.
From Thursday through the weekend, the pattern remains the same as the ITCZ/monsoon trough, which remains near and across T&T. As a result, winds will be light to at times from the south, especially during the late morning through the afternoon and overnight hours. This will lead to northward-moving showers and thunderstorms, which have two implications.
The first will be evening showers and thunderstorms off of northern Venezuela, moving northward overnight towards T&T and into the Gulf of Paria. This will lead to larger-than-usual waves, particularly along south-facing coastlines and choppy seas in usually tranquil areas.
Secondly, strong daytime heating and sea breeze convergence will trigger cloud, shower, and thunderstorm development, particularly during the late morning through the afternoon. As activity gets pushed over the Central and Northern Ranges from the south to the north, showers and thunderstorms will likely intensify, particularly along the East-West Corridor and the western half of Trinidad.
Light steering currents, which move showers and thunderstorms through the atmosphere, are forecast, which will also compound the locally heavy rainfall threat in highly isolated areas.
Given that the ITCZ will be across T&T and activity associated with the ITCZ peaks during the early morning hours, as well as top models showing a relatively saturated low-level environment, locally isolated heavy rainfall is possible, but widespread heavy rainfall is not likely. Keep an eye out for any official alerts from the Trinidad and Tobago Meteorological Service.