5 Things You Need To Know About The 2022 Dry Season

Sunrise in Southern Trinidad on January 9th, 2022 (Sham Sahadeo)

It is that time of year again where water from the skies and the taps become an even rarer commodity. In a stark contrast from the 2021 “Dry” Season, which had many floods, Adverse Weather Alerts, and felt like the 2020 Wet Season 2.0, 2022 is promising much sunnier skies, according to the Trinidad and Tobago Meteorological Service (TTMS).

2022 Dry Season Is Forecast To Be Drier Than Usual

Category of rainfall likely for the 2022 Dry Season with the highest chance of occurrence expressed as probabilities and color-coded on the map. Blues indicate that it is more likely for above-normal rainfall to occur than for below normal or near normal. Browns indicate it is more likely for below normal rainfall, while greens indicate it is more likely for near-normal rainfall. Normal is defined by the rainfall that was observed in the middle one-third of the Dry Seasons over the 1991-2020 period used as the climate normal.(Trinidad and Tobago Meteorological Service)
Category of rainfall likely for the 2022 Dry Season with the highest chance of occurrence expressed as probabilities and color-coded on the map. Blues indicate that it is more likely for above-normal rainfall to occur than for below normal or near normal. Browns indicate it is more likely for below normal rainfall, while greens indicate it is more likely for near-normal rainfall. Normal is defined by the rainfall observed in the middle one-third of the Dry Seasons over the 1991-2020 period used as the climate normal. (Trinidad and Tobago Meteorological Service)

The dry season is never devoid of rainfall. Low-level cloud patches, troughs, and shearlines bring occasional cloudy skies and brief showers to the country. When favorable conditions come together, uncommon thunderstorms can also occur during this five to six-month period from January through May or early June. However, the dry season is characterized in Trinidad and Tobago, where lower than average rainfall occurs.

In 2022, this months-long span of overall dry weather is forecast to be drier than usual, according to the Met Office. In their outlook, they indicate a “strongly enhanced signal for suppression of rainfall that tilts the odds in favor of drier than usual conditions.” Across most of the country, the odds of below-average rainfall totals are above 55%. For an average dry season, T&T receives 412 millimeters of rainfall.

However, as we’ve seen this past week, the onset of drying is expected to be delayed as January is forecast to receive near-normal rainfall. Drying is forecast to intensify through March and April, typically the driest and the hottest dry season months, respectively. On the other hand, February is forecast to be the driest of the 2022 Dry Season.

Tobago To Be The Driest

Possible accumulated rainfall totals with the highest chance of occurring during the 2022 Dry Season. (Trinidad and Tobago Meteorological Service)
Possible accumulated rainfall totals with the highest chance of occurring during the 2022 Dry Season. (Trinidad and Tobago Meteorological Service)

The TTMS’ outlook shows across both islands, rainfall percentages will vary between 46% to 90% of the national 412-millimeter-rainfall average. The majority of Trinidad is likely to get percentages of average seasonal rainfall that are less than 76% of average. For those looking for rainfall, the largest percentage of average seasonal rainfall ranges between 76% and 90% and is confined to portions of northeast and northwest Trinidad.

Specifically, areas across northeast Trinidad, near Sangre Grande, Valencia, Toco, Fishing Pond, and Plum Mitan and northeast Tobago near Scarborough to Mount Saint George, have the highest probabilities for rainfall totals greater than 412 mm during the season.

In Tobago, seasonal rainfall totals are likely to range between 200 and 350 mm, with the lowest total likely in the windward part of the island near Kings Bay and Speyside. Both the southwestern and northeastern ends of Tobago are likely to get a percentage of average totals less than 76%. Elsewhere, values are likely to be between 76% and 90%.

Low Chance For A Short-Term Drought

Chances for extremely dry conditions over the 2022 Dry Season. Extremely dry conditions refer to the lowest 10% of Dry Season total rainfall amounts in the historical record.
Chances for extremely dry conditions over the 2022 Dry Season. Extremely dry conditions refer to the lowest 10% of Dry Season total rainfall amounts in the historical record. (Trinidad and Tobago Meteorological Service)

According to the Met Office, the probability for rainfall totals to be in the lowest 10% of all dry season rainfall totals ranges between 20-32%, which is considered low to moderate. However, they maintained that the chances for short-term drought conditions to develop during the 2022 Dry Season are “likely to be low.”

There are five types of drought:

  • Meteorological Drought: A prolonged time with less than average precipitation.
  • Hydrological Drought: When low water supply becomes evident in the water system.
  • Agricultural Drought: When crops become affected by drought.
  • Socioeconomic Drought: When the supply and demand of various commodities is affected by drought.
  • Ecological Drought: When natural ecosystems are affected by drought.

Meteorological drought is usually the first to appear as it is easily quantified through different indices and rainfall measurements.

For the 2022 Dry Season, while a drought isn’t likely at this time, the country is likely to get about 113 dry days during the season, which is slightly more than the average of 109 dry days. According to the TTMS, a dry day has less than 1.0 millimeters of rainfall.

Also, T&T has a tiered system of warnings before a drought is declared based on the Standard Precipitation Index. This warning system ranges from no concern, little concern, heightened concern, a Dry Spell Watch, Dry Spell Warning, Drought Watch, and Drought Warning.

The country usually receives three to eight seven-day dry spells and one to five ten-day dry spells in the dry season. For the 2022 Dry Season, there is a 68% probability for four to nine seven-day dry spells and two to six ten-day dry spells.

Overall Temperatures To Be Warmer

The map shows the color-coded category (below-normal, above-normal, and near-normal) of maximum and maximum temperatures that are most likely to occur across Trinidad and Tobago for the 2022 Dry Season. The color-coded blocks with the numbers at the bottom give the likelihood for each forecast category to occur. (Trinidad and Tobago Meteorological Service)
The map shows the color-coded category (below-normal, above-normal, and near-normal) of maximum and maximum temperatures that are most likely to occur across Trinidad and Tobago for the 2022 Dry Season. The color-coded blocks with the numbers at the bottom give the likelihood for each forecast category to occur. (Trinidad and Tobago Meteorological Service)

2022 is forecast to be warmer than average across all average temperature metrics: minimum lows, daily averages, and maximum highs.

The Met Office notes that the greatest odds for warmer than average nights and warmer than average days are located in the cities, most urban and built-up areas.

March is usually the start of the local Heat Season, which runs through October. During the 2022 Dry Season, maximum temperatures are likely to peak near 33.5°C, which is most likely to occur between April and May.

“Very Cold” Nights Still Expected

Preliminary minimum low temperatures across Trinidad and Tobago on Wednesday, January 5th, 2022.

For Trinidad and Tobago, minimum low temperatures below 20.0°C are considered very cold. The TTMS forecasts at least three very cold nights between January and March 2022.

At Piarco, temperatures have dipped below 20.0°C once on January 5th, 2022. Cool nighttime temperatures are normal from January through March as colder and drier air further north makes its way southward.

When dry (and at times cool) air is present across T&T, with a cloud-free night and near-calm winds, maximum radiational cooling occurs, allowing heat to escape the earth’s surface.

What Should You Do This Dry Season?

Percentage of average rainfall totals likely for the 2022 Dry Season (Trinidad and Tobago Meteorological Service)
Percentage of average rainfall totals likely for the 2022 Dry Season (Trinidad and Tobago Meteorological Service)

The major impact of a drier-than-usual dry season will be on the nation’s water supply, particularly towards the latter half of the dry season. Surface water (rivers, reservoirs, and dams) accounts for 60% of the nation’s freshwater supply, while groundwater (aquifers) accounts for 23%. The Met Office is forecasting between 63% and 72% of an average dry season rainfall to accumulate at the nation’s reservoirs.

Rainfall deficits will negatively impact water management due to reduced recharge rates, slower and lower than usual stream flows, and water levels. Thus, the public needs to conserve, store and manage water safely and adequately while the water and energy sectors revisit contingency plans and upgrade based on historical extremes rather than averages.

With dry conditions, there will be an increased potential for bush, forest, and landfill fires potential as the season progresses, especially during late February and March. Additionally, these fires, along with smoke, Saharan Dust, and blowing dust, can reduce air quality across the country, so take steps to protect your home from air pollution. If you live in an area close to trees and bushes, now would be a great time to trim and clear around your home.

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