As of 6:00 PM Tuesday 6th August 2019, partly cloudy skies are ongoing across much of Trinidad and Tobago. Isolated showers are affecting parts of Western and Eastern Trinidad, as well as Tobago. Additional showers are likely overnight through tomorrow as the ITCZ, local climatic features affect T&T.
A few thunderstorms are also forecast, particularly across Eastern and Southern Trinidad overnight and Western Trinidad on Wednesday.
Street/flash flooding, gusty winds, landslides and frequent thunder and lightning possible.
There are no alerts, watches or warnings in effect for Trinidad and Tobago from the Trinidad and Tobago Meteorological Service as of 6:00 PM Tuesday.
What We Know
Winds are now mostly southeast to east across Trinidad and Tobago as the influence of Tropical Wave 32 finally wanes across the region. The ITCZ is moving southward and is present across Trinidad and Tobago.
This activity, combined with local climatic features such as daytime heating and sea breeze convergence, has triggered locally heavy showers and thunderstorms across and near Trinidad and Tobago.
An isolated thunderstorm across Couva dumped in excess of 50 millimeters of rain in 40 minutes, between 4:29 PM and 5:09 PM. This triggered street flooding across Couva.
High total precipitable moisture and minimal wind shear are present. In addition, neutral upper-level divergence and low-level convergence are present across T&T. Regardless, conditions are favorable for showers and thunderstorm development over the next 12-24 hours across T&T.
The Adverse Weather Alert by the Trinidad and Tobago Meteorological Service has been cancelled as of 1:39 PM Tuesday 6th August 2019. This is due to, “the threat of significant activity and accompanying impacts has now decreased. However, the chance of heavy showers and thunderstorm activity remains in the forecast for the next several days.”
Information from the Trinidad and Tobago Meteorological Service concerning the Adverse Weather Alert Cancellation on August 6th, 2019.
What We Expect (For T&T)
The Takeaway: Isolated to scattered showers are likely overnight tonight through Wednesday across Trinidad and Tobago. Isolated thunderstorms is forecast to favor Eastern and Southern Trinidad overnight and Western Trinidad on Wednesday.
This activity is forecast to interrupt mostly cloudy skies over the next 36 hours, at times sunny on Wednesday, with the heaviest activity favoring Northern and Western parts of Trinidad.
Activity is forecast subside by Wednesday night, but begin again after mightning into Thursday as Tropical Wave 33 approaches the region.
Generally, widespread severe weather is not likely. Localized to scattered severe weather reports are possible, with heavy rainfall.
Light easterly to southeasterly winds are forecast. This overall wind regime dictates the forward speed (or lack thereof) of shower and thunderstorm activity and allows for heavy shower and thunderstorm development, focusing along Western Trinidad and along the Northern Range
Street/Flash Flooding and gusty winds possible continue to be possible through Thursday as periods of late morning through afternoon showers and thunderstorms persist across mainly Trinidad, but also Tobago.
Overnight – Isolated showers and thunderstorms are likely, interrupting a mostly partly to mostly cloudy night across both islands.
Wednesday – After some early morning showers, favoring Trinidad, brief partly to mostly cloudy skies are forecast with even some sunshine. By the late morning through the late afternoon, showers and thunderstorms are forecast across Trinidad, with isolated activity possible across Tobago. Thunderstorms are forecast to favor the Western half of Trinidad. Conditions to become settled by the late evening, with another round of showers and thunderstorms possible after midnight into Thursday.
Based on the latest model guidance, isolated to scattered showers and isolated thunderstorms are forecast to move across both islands, with heavier activity favoring much of Trinidad over the next 24-36 hours.
Locally Heavy Rainfall & Flooding: Next 36 hours – Based on the latest model runs on Tuesday evening, from Tuesday afternoon (2:00 PM) through Thursday (2:00 AM), generally, over the 36 hour period, models are in agreement of fewer than 20 millimeters across of Trinidad and Tobago and between 20-40 millimeters across isolated areas of Trinidad and up to 50 millimeters across Northwestern Trinidad.
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, based on the above-mentioned forecast rainfall totals associated with the ITCZ as it moves across the area over the next 24-36 hours.
Frequent Lightning: In addition, with thunderstorms, frequent lightning is likely.
Gusty Winds: Gusty winds, generally between 40 and 50 KM/H are possible Gusty winds are most likely prior to, in the vicinity of, or occur during heavy showers or thunderstorms. With wind gusts up to 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.
Landslides: Heavy showers across the Northern Range may trigger landslides in landslide-prone areas. Particularly in areas that receive heavy rainfall, landslides and/or mudflows may occur across both islands. These landslides, in addition to gusty winds, may down trees, utility poles and impede traffic on roadways.
Tonight’s minimum temperatures are forecast to be near 24°C at Piarco, Trinidad, and 26°C at Crown Point, Tobago.
Tomorrow’s maximum high temperatures across T&T are forecast to be near 32°C at Piarco, Trinidad and 31°C at Crown Point, Tobago. Tomorrow, similar maximum high temperatures are forecast. Heat indices may top at 40°C across Trinidad and 35°C across Tobago. The heat index is an index that combines air temperature and relative humidity, generating a “feel’s like” temperature.
Seas are forecast to remain moderate in open waters through the next day or so. Waves in open waters are forecast between 1.5 to 2.0 meters, particularly East of Trinidad and Tobago. In sheltered areas, seas to remain below 1.0 meters but choppy during heavy showers or thunderstorms. Winds are forecast to remain near 10-15 knots, from the east to southeast.