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Periods of Showers, Thunderstorms Forecast For T&T Over Next 5 Days

May 20, 2023
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Though Trinidad and Tobago is not officially in the 2023 Wet Season, showers and thunderstorms are forecast across the area over the next five days, with flooding concerns likely. Severe weather is possible on Monday.

What you need to know

— Rainfall: Through Friday, most areas are forecast to receive up to 75 millimeters during the five-day period. In isolated areas favoring eastern and western coastal Trinidad, particularly in areas that experience persisting heavy showers or thunderstorms, five-day rainfall accumulations could exceed 150 millimeters.
— Saharan Dust: Little to no Saharan Dust is forecast across Trinidad and Tobago over the next five days. However, a mild surge is forecast for May 23rd through May 25th.
— Hazards: The main hazard over the next five days will be street/flash flooding and gusty winds. Though overall winds are forecast to remain near calm or light, in heavy showers or thunderstorms, wind gusts may exceed 45 KM/H, with winds possibly gusting upwards of 55 KM/H on Monday. By mid-week, landslides are possible as soils become increasingly saturated. The highest chances for severe weather exist on Monday, where very heavy rainfall and strong winds are likely.
— Marine: Seas are forecast to be moderate in open waters with waves up to 2.0 meters and near 1.0 meter in sheltered areas. By mid-week, seas are forecast to become slight, with waves in open waters reaching up to 1.25 meters. Seas may become locally choppy or rough in heavy showers or thunderstorms. Spring tides are forecast to end on Monday.

Latest Alerts

2 minute read

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…
October 25, 2024

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

The Forecast

Sunday

Sunday
6 10 0 1
Partly to mostly cloudy with scattered showers and rain across both islands. From the mid-morning, heavy showers and thunderstorms are possible, favoring southeastern areas initially, spreading northwestward across both islands. Conditions to gradually settle by the late afternoon, with the odd shower and light rain possible. By nightfall, a resurgence in showers and isolated thunderstorms is possible, favoring eastern Trinidad and Tobago initially. Gusty winds, street/flash flooding possible.
Partly to mostly cloudy with scattered showers and rain across both islands. From the mid-morning, heavy showers and thunderstorms are possible, favoring southeastern areas initially, spreading northwestward across both islands. Conditions to gradually settle by the late afternoon, with the odd shower and light rain possible. By nightfall, a resurgence in showers and isolated thunderstorms is possible, favoring eastern Trinidad and Tobago initially. Gusty winds, street/flash flooding possible.
6/10
Thunderstorm Chances
Medium – High

Monday

Monday
8 10 0 1
Periods of rain, showers and isolated to scattered thunderstorms are forecast across both islands with peak inclement weather forecast from mid-morning and continue into the evening. A few thunderstorms may become strong/severe with strong, damaging winds and heavy rainfall being the primary, but not sole hazards. See the forecast discussion for more information. Rainfall to continue into the night with rain, showers and isolated thunderstorms. Street/flash flooding likely.
Periods of rain, showers and isolated to scattered thunderstorms are forecast across both islands with peak inclement weather forecast from mid-morning and continue into the evening. A few thunderstorms may become strong/severe with strong, damaging winds and heavy rainfall being the primary, but not sole hazards. See the forecast discussion for more information. Rainfall to continue into the night with rain, showers and isolated thunderstorms. Street/flash flooding likely.
8/10
Thunderstorm Chances
High – Very High

Tuesday

Tuesday
7 10 0 1
Cloudy conditions to be interrupted with periods of rain, showers and thunderstorms from the early morning, gradually diminishing by the early afternoon with increasing sunshine. A mostly settled evening with partly cloudy skies. Gusty winds, street/flash flooding possible.
Cloudy conditions to be interrupted with periods of rain, showers and thunderstorms from the early morning, gradually diminishing by the early afternoon with increasing sunshine. A mostly settled evening with partly cloudy skies. Gusty winds, street/flash flooding possible.
7/10
Thunderstorm Chances
High

Wednesday

Wednesday
3 10 0 1
Mostly sunny with brisk isolated showers throughout the day, particularly during the afternoon. An initially settled night, with the chance of a heavy shower or thunderstorm favoring eastern areas nearing midnight.
Mostly sunny with brisk isolated showers throughout the day, particularly during the afternoon. An initially settled night, with the chance of a heavy shower or thunderstorm favoring eastern areas nearing midnight.
3/10
Thunderstorm Chances
Low

Thursday

Thursday
5 10 0 1
Variably cloudy conditions with isolated showers and thunderstorms favoring western half of Trinidad during the early morning and early afternoon periods. Elsewhere, partly to mostly cloudy with the odd shower. Gusty winds, street/flash flooding possible.
Variably cloudy conditions with isolated showers and thunderstorms favoring western half of Trinidad during the early morning and early afternoon periods. Elsewhere, partly to mostly cloudy with the odd shower. Gusty winds, street/flash flooding possible.
5/10
Thunderstorm Chances
Medium

Marine Forecast

Temperatures

Generally, over the next five days, maximum highs and minimum lows are forecast to be below average due to increased cloud cover.

Tuesday through Saturday

Low: 22-24°C

High: 28-31°C

Maximum high temperatures are forecast to range between 28°C to 31°C trending cooler across eastern Trinidad and higher across urbanized areas of Trinidad, where in built-up areas, maximum high temperatures could exceed 31°C. Minimum lows are forecast to remain warm, ranging between 22°C and 24°C in Trinidad and Tobago, trending cooler in interior areas. The heat index will generally exceed 34°C over the next five days.

Forecast Impacts

Flooding

Flooding
7 10 0 1
Over the next five days, up to 75 millimeters of rain is forecast across most areas in both islands. Totals exceeding 100 millimeters are forecast particularly across eastern Trinidad and isolated areas across western Trinidad. Isolated totals could exceed 150 millimeters over the five-day period. Note, with light winds, slow-moving showers and thunderstorms are possible, with these high-rainfall accumulations occurring in short periods.
Over the next five days, up to 75 millimeters of rain is forecast across most areas in both islands. Totals exceeding 100 millimeters are forecast particularly across eastern Trinidad and isolated areas across western Trinidad. Isolated totals could exceed 150 millimeters over the five-day period. Note, with light winds, slow-moving showers and thunderstorms are possible, with these high-rainfall accumulations occurring in short periods.
7/10
Likelihood
High

Forecast Rainfall Totals

  • Sunday: Between 5 and 15 millimetres of rainfall across the country, trending higher across eastern Trinidad and western coastal Trinidad in localized areas, with isolated totals exceeding 25 millimeters.
  • Monday: Up to 25 millimeters across the country, trending higher across Trinidad. In isolated areas across western coastal and eastern Trinidad, rainfall totals could exceed 25 millimeters. Note: There is the potential for very heavy, flooding rainfall on Monday, particularly across northwestern Trinidad. See the discussion for more information.
  • Tuesday: Up to 10 millimeters across both islands, trending higher across western coastal Trinidad, with totals reaching as high as 25 millimeters.
  • Wednesday: Less than 5 millimeters of rainfall forecast across both islands, with little to no rainfall forecast across western areas of both islands.
  • Thursday: Between 10 and 20 millimeters of rainfall across Trinidad, favoring western and central areas of the island. Across Tobago, little to no rainfall is forecast.

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
On Monday, there are higher-than-normal chances for strong thunderstorms to develop. Near calm winds at the surface, with veering winds through the atmosphere, strong upper-level winds and a very saturated atmosphere are all supportive of strong thunderstorm development, particularly during the afternoon.
On Monday, there are higher-than-normal chances for strong thunderstorms to develop. Near calm winds at the surface, with veering winds through the atmosphere, strong upper-level winds and a very saturated atmosphere are all supportive of strong thunderstorm development, particularly during the afternoon.
6/10
Likelihood
Medium – High

Gusty Winds

Gusty Winds
6 10 0 1
Over the next five days, sustained winds exceeding 30 KM/H are possible in heavy shower or thunderstorm activity, with higher gusts possible exceeding 45 KM/H, with gusts exceeding 55 KM/H possible on Monday.
Over the next five days, sustained winds exceeding 30 KM/H are possible in heavy shower or thunderstorm activity, with higher gusts possible exceeding 45 KM/H, with gusts exceeding 55 KM/H possible on Monday.
6/10
Likelihood
Medium – High

Possible impacts include localized wind damage to trees, power lines, and small structures.

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.

Through the forecast period, isolated to scattered rainfall is forecast, with isolated rainfall forecast on Wednesday.

Forecast Discussion

Tropical Update

All tropical waves to date have skirted south of Trinidad and Tobago, producing no measurable rainfall thus, officially, the 2023 Wet Season has not begun. However, over the next coming days, periods of showers and thunderstorms are forecast, with potential severe weather on Monday, May 22nd, 2023.

On Saturday night, a surface-to-low-level confluent pattern (winds slowing down and piling up, causing convergence) was in place across Trinidad and Tobago, resulting in cloudy conditions and a few showers. Moisture levels are increasing across the area, which is supporting increasingly cloudy conditions and will fuel activity in the coming days.

By Sunday, a combination of several mid-level troughs, an upper-level jet, and increasing atmospheric moisture will support increasingly cloudy conditions, periods of showers and isolated thunderstorms from Sunday through the first half of Tuesday.

Particularly on Monday, the atmosphere is forecast to be primed for heavy rainfall, with nearly saturated conditions at the 300-850 millibar levels, light surface winds, veering winds through the atmosphere, and strong upper-level winds with sufficient instability at the low to upper levels of the atmosphere and a divergent upper-level pattern. All severe hazards are on the table, including strong winds exceeding 55 KM/H, and heavy rainfall rates exceeding 25 mm/hour, with a favorable atmospheric profile for funnel cloud development. If a funnel cloud touches down on land or water, it will become a tornado or waterspout, respectively. The highest chances for this type of activity exist along western Trinidad. The sole limiting favor will be strong wind shear up to 40 knots from the west, resulting in overall heavier rainfall favoring the eastern half of Trinidad. In addition, with slow steering currents, showers and thunderstorms will not be moving quickly, leading to possible prolonged rainfall. However, across isolated areas of western Trinidad, high rainfall accumulations are possible.

Conditions are set to get increasingly stable from Tuesday evening into Wednesday, mid to upper-level conditions are forecast to become slightly drier, with reduced rainfall chances. However, by Thursday and into the upcoming weekend, conditions become increasingly moist across all levels of the atmosphere yet again and shear is set to decrease, with sufficient instability and moisture for shower and thunderstorm development.

In addition, across the region this week, an arriving convectively-coupled Kelvin wave is forecast to enhance convection and overall rainfall totals.

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