Another day of light southeasterly to southerly winds are forecast and combined with strong daytime heating, isolated showers and thunderstorms are possible, mainly across Western and Northern halves of Trinidad by the late morning, through the afternoon.
The risk of scattered to widespread heavy rainfall is very low to none. However, heat-driven showers and thunderstorms can be intense, producing localized and brief street flooding and gusty winds. This activity will mainly be possible across the western and northern halves of Trinidad. With light winds, funnel clouds are also possible.
There are no alerts, watches, or warnings from the Trinidad and Tobago Meteorological Service at this time.
Overview: Abundant low-level moisture is present as the ITCZ remains over T&T, but a dry mid to upper-level environment is in place. This means cloud and shower development will be limited unless strong daytime heating, orographic lift (along the Northern Range), and sea breeze convergence can act as triggers for afternoon shower and thunderstorm development.
Forecast: A mostly hot and sunny day is forecast across both islands. By the late morning, partly cloudy skies are forecast to develop across the Western half of Trinidad. By 11 AM, isolated showers are possible, mainly across Western Coastal and North-Central areas of Trinidad, as well as along the south-facing slopes of the Northern Range. Isolated thunderstorms are possible, favoring the Western half of Trinidad through the afternoon.
Conditions are forecast to settle by the evening. Still, models show an increase in shower and thunderstorm activity overnight, but this depends on if convection can develop along the Northern coast of Venezuela and drift northward. If this occurs, the heavier activity will favor Southern and Southwestern Trinidad, with hazardous marine conditions in the Gulf of Paria.
Marine: Seas forecast to be slight across Northern and Southern coasts of Trinidad, as well as the Western coasts of Tobago, with waves up to 1.2 meters in open waters. Across the Eastern coasts of Trinidad and Tobago, seas will be slight to moderate with waves up to 1.5 meters, becoming more agitated into Friday. In sheltered areas, near calm but shower and thunderstorm activity may agitate sea conditions.
Hazards: The main hazards include brief, localized heavy rainfall, which may reduce visibility and gusty winds up to and in excess of 50 KM/H. Street or flash flooding will be possible in slow-moving showers and thunderstorms. In thunderstorm activity, frequent lightning is also possible. Gusty winds may cause power dips/outages, downed trees, and localized wind damage. With light winds, funnel clouds are also possible. Across the Northern Range, landslides are possible.
Across both islands, hot and humid conditions are forecast. The maximum high for Trinidad is forecast to be near 34.0°C, up to 36.0°C in urban and built-up areas, particularly between 10:00 AM and 2:00 PM. In Tobago, the maximum high is forecast to be near 33.0°C
Temperatures in cities, such as Port of Spain, tend to be much higher than surrounding locations due to a phenomenon called the Urban Heat Island Effect. There are several causes, but the main instigator for this phenomenon tends to be increased dark surfaces such as roads and pavement in cities, which absorb solar radiation more than surrounding areas.
The Heat Index
The heat index will be relatively high on Thursday across Trinidad and Tobago. The heat index and is a combination of air temperature and relative humidity, determining what the air feels like to a person, i.e., how hot it actually feels.
Across Trinidad, the maximum heat index is forecast to be between 35°C and 40°C and even higher in urbanized areas. In Tobago, the maximum heat index is forecast to be between 33°C and 38°C
The heat index is important because of sweating. Your body sweats to cool the skin and maintain a constant, healthy body temperature. This cooling process means that the sweat has to evaporate off the skin to remove heat. However, if the sweat is unable to evaporate, the body isn’t able to regulate temperature.
Heat index is generally classified into four categories: caution, extreme caution, dangerous, and extremely dangerous. On Thursday, the heat index is forecast to be near levels where extreme caution is needed and, in some areas, at dangerous levels! Remain hydrated!
Sustained surface winds will be light to nonexistent. However, during heavy showers and thunderstorms, sustained winds between 25 KM/H and 35 KM/H with gusts up to and in excess of 50 KM/H are possible.
With wind gusts in excess of 50 KM/H, whole trees are expected to be in motion, and there may be some inconvenience when walking against the wind gusts. Light outdoor objects may topple or become airborne such as garbage cans, potted plants, loose galvanize or construction material, and other outdoor furniture. Tents may jump. Older/weaker trees may fall, bringing down utility poles and lines.
Across most areas of Trinidad and Tobago, little to no rainfall is anticipated, with maximum accumulation totals near 5 millimeters. However, across parts of Western and Northern Trinidad, particularly along the south-facing slopes of the Northern Range and the Western half of Trinidad, rainfall totals of up to 25 millimeters are possible, with isolated totals in excess of 25 millimeters, particularly in slow-moving downpours or thunderstorms.
Generally, with heavy showers and thunderstorm activity, street flooding, particularly in flood-prone areas or areas with poor drainage, is possible as well as flash flooding in areas where more prolonged heavy rainfall may occur.
Frequent Lightning: Frequent lightning is possible in thunderstorm activity. Lightning can cause power outages, voltage dips, damage to life and property, particularly during cloud-to-ground lightning strikes.
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 to scattered rainfall is forecast on Thursday. Most will experience hot and sunny conditions.