Minimum Temperatures Recorded Across Trinidad on Sunday 27th January 2019
This weekend saw several areas across Trinidad dip below 20°C. Multiple areas reported temperatures of 17°C to 18°C across Central and Northern Trinidad, particularly on Sunday 27th January 2019.
Temperatures across Tobago, albeit still cold, remained near 23°C.
Low temperatures during this time of year is normal, as the Northern Hemisphere experiences winter.
Cool temperatures across Trinidad result of several factors occurring:
- Calm/near calm winds
- Almost no cloud coverage
- Winds originating from the North in the lower levels of the atmosphere (over Trinidad)
- Low amounts of low-level moisture (water vapor)
The dew point, which is the atmospheric temperature below which water droplets begin to condense and dew can form, meteorologists can determine both the moisture content of the atmosphere near the surface, as well as an estimate for the minimum temperature.
A lower dew point means that there is less water vapor in the air. Water vapor can absorb and radiate heat back to the surface. Hence, the lower the water vapor content, more infrared radiation (i.e. long-wave radiation) can escape from the surface of the earth and cause rapid cooling.
Calm winds and no cloud coverage are due to a persistent sub-tropical high pressure system which has dominated the weather for much of January, causing dry air at mid and upper levels of the atmosphere, inhibiting cloud formation.
Lack of cloud coverage also leads to fairly warm days, where temperatures can reach 32°C.
Particularly during El Niño years, winter storms move further southward across the United States, increasing the likelihood of cold frontal systems moving across the Caribbean and further dipping temperatures. On the rare occasion a cold front does manage to make it as far south as Trinidad and Tobago, cold conditions would be due to a process called advection, where there is a horizontal mass movement of air.
For vulnerable persons, who might be especially susceptible to cooler temperatures, such as babies or people suffering from arthritis, it may be best to layer up as a way to keep warm at night.
According to data from the Trinidad and Tobago Meteorological Service, the coldest temperature ever recorded at Piarco International Airport was 16.1°C, recorded in January 1964.
On Saturday morning, temperatures across Trinidad remained generally between 19°C and 21°C. Overnight, increased low-level moisture moved across Trinidad, producing showers and generally cloudy weather which dominated conditions throughout the day.
This increased low-level moisture trapped most of the long-wave radiation near the surface and kept low temperatures for the most part above 20°C.
On Sunday, much cooler temperatures were expected, as notably drier air moved across Trinidad and Tobago. The forecast low temperature at Piarco was 18°C according to the Trinidad and Tobago Meteorological Service’s 4PM forecast on Saturday 26th January 2019.
While some cloud cover did prevent temperatures from dipping as low as 18°C at Piarco, much of the country did experience temperatures at or below 18°C.
Several accounts of 17°C to 18°C temperatures were reported from valley areas of Northern Trinidad, as well as interior Central and Southern Trinidad confirmed cooler temperatures.
These cool temperatures were confirmed by the few weather stations that automatically record temperatures. Carapichima, in Central Trinidad recorded an impressively cool temperature of 17.8°C at 6:30AM Sunday morning!
On Monday, due to an influx of moist air and low level clouds, still remaining across the islands on Monday morning, cooling near the surface was limited. Increased low-level moisture will continue to limit cooling through the next day or so, and produce humid conditions.
Temperature Forecast for This Week
Latest model data continue to indicate that a mild to moderate amount of low-level moisture will be present Monday and Tuesday, which is likely to bring some cloud cover and even some early morning isolated showers.
As mentioned above, increased low-level moisture can trap heat at the surface, limiting cooling. However, lows across Trinidad are still expected to remain between 20°C to 22°C, with lower temperatures possible across interior parts of the island.
On Wednesday through Friday, most models are in agreement of dry air (lacking low-level moisture) to move into Trinidad and Tobago. Dry air will result in cooler temperatures across the island over the later part of the week overnight and early morning periods.
In fact, model guidance shows that temperatures of 17°C to 18°C are likely across interior parts of the island, predominantly on Wednesday and Thursday.
Updated temperature forecasts will be posted throughout the week, so keep checking to remain updated as the temperature forecast can change due to the fickle nature of the atmosphere.