Oppressive heat is finally finished with Trinidad and Tobago, with near-average daytime maximum highs and nighttime minimum lows forecast for the remainder of October.
What you need to know
— What has happened: Over the last two weeks, Trinidad and Tobago has experienced elevated levels of heat, occasionally surpassing the definition for a hot day at both Piarco (maximum temperatures at or above 34°C) and Crown Point (maximum temperatures at or above 33°C).
— What is expected: Maximum high temperatures are forecast to be near average for both Trinidad and Tobago for the remainder of October.
— Hazards: While temperatures are not forecast to reach excessively hot levels, the heat index, or what outside feels like, will still require caution through the end of October, resulting in the risk of heat exhaustion and heat stroke amongst the population, with heat stress possible for crops and animals.
Latest Alert
Adverse Weather Alert Discontinued For T&T
Trinidad and Tobago is NOT under any tropical storm or hurricane threat, watch, or warning at this time.
The Hot Spell Alert
Officially, according to the TTMS, a hot spell is declared when Trinidad and Tobago experiences maximum high temperatures reach or exceed 34°C at Piarco AND maximum high temperatures reach or exceed 33°C at Crown Point, Tobago. Historically, the maximum high-temperature threshold for Tobago was at or above 32°C, but this was changed in August 2023, as the definition of a hot day is meant to capture maximum high temperatures in the top 95th percentile of temperatures and, according to the TTMS climatologist office, 32°C was too low. Hot spells are the same as heat waves.
The Trinidad and Tobago Meteorological Service discontinued the Hot Spell Alert (Yellow Level) on Monday, October 16th, 2023, at 4:02 PM, for both Trinidad and Tobago.
Trinidad and Tobago is not under any tropical storm watch or warning at this time.
In their discontinuation message, they advise, “As Trinidad and Tobago approaches the end of the heat season, the likelihood of extended periods of extremely high daily temperatures has significantly decreased. This is due to anticipated cloudy and/or rainy conditions associated with wet weather meteorological features over the coming days. The daily temperatures are forecast to be warm as usual for the rest of October.”
The color of the alert indicates the severity of the event and the probability of the event occurring. Currently, the alert level is at Green, as the discontinuation was issued, but the certainty is at its lowest on the risk matrix, at unlikely, and the possible impacts are still moderate.
Generally, at Green Level, according to the TTMS, there is a low risk to public safety, livelihoods, and property. For a moderate alert, even in a discontinuation alert, there is the potential for possible injuries, where behavioral changes are required to ensure safety. Generally, there may be minor damage to property, with income-earning temporarily disrupted and a couple of communities affected more than others.
The Met Office is advising the public to continue to monitor the weather conditions, stay hydrated, and visit the TTMS’ website for the latest weather forecast and alerts.
What caused the excessive heat?
Since mid-August, multiple tropical cyclones have safely moved north of Trinidad and Tobago. The result of these stronger low-pressure systems traversing north of the region is weaker surface winds, coming from the southeast and south, to near calm and calm at times.
Though the mid to upper-level environment remains fairly dry, the low-level environment has marginal amounts of moisture, which leads to elevated humidity. As a result, high amounts of warm air remaining near the surface, while at night, occasional mid/upper-level clouds prevent the escape of heat into the atmosphere.
The result is warm, humid nights and hot, humid days across not only Trinidad and Tobago but the remainder of the Lesser Antilles.
On a larger scale, the solar altitude, or the angle of the sun relative to the Earth’s horizon, is at 90° across T&T (occurred on August 25th). When this occurs, solar radiation is concentrated over a smaller surface area, causing warmer temperatures.
Trinidad and Tobago is also entrenched in its heat season, which runs from March to October, with the first peak in April and May and the second peak in late August through early October. During these months, the islands experience mostly hot sunny periods and warm nights. Winds are generally weak but occasionally moderate strength from the east to southeast with speeds of 20-30 KM/H.
According to the Met Office, there are many climatic features working together to promote warmer to hotter days this month. “The winds are calm to light, with fewer cloudy periods, which enables greater incoming solar radiation, particularly during the mid-morning to afternoon periods:
- A moderately strong El Nino which generally restricts cloud development.
- A negative phase of the North Atlantic Oscillation (NAO) encourages weak winds across the Caribbean.
- A warmer than usual Atlantic Ocean Sea Surface Temperatures (SSTs) east of the Trinidad and Tobago.
- The apparent local position of the sun at our latitude.
- The southeasterly flow of wind from the equatorial region.
