March 2023 has been unusually dry across Trinidad and Tobago, but that is about to change in the coming 72 hours. A pool of deep-layered moisture is forecast to move across Trinidad and Tobago, with some upper-level support for cloudiness, showers, and even the chance for an isolated thunderstorm. Thunderstorms are uncommon in the Dry Season, but certainly not unheard of.
What you need to know
— Rainfall: Over the next five days, up to 25 millimeters of rainfall is forecast across both islands, with isolated totals between 50 and 75 millimeters possible, favoring eastern and southern areas of Trinidad, as well as isolated western areas with heavy showers or thunderstorms.
— Saharan Dust: A moderate to high concentration surge of Saharan Dust is forecast to begin affecting T&T from Monday, April 3rd, 2023.
— Hazards: Over the next five days, the main hazard will be wind gusts up to 50 KM/H, generally accompanying isolated showers on Friday and Saturday. Localized, short-lived street flooding is possible in isolated heavy showers or thunderstorms.
— Marine: Seas are forecast to be moderate in open waters with waves up to 2.0 meters, but in nearshore areas of eastern and northern T&T, as well as along sheltered western areas of both islands, seas will remain hazardous due to long-period swells.
Latest Alert
There are no alerts, watches, or warnings in effect for Trinidad, Tobago or surrounding marine areas.
Trinidad and Tobago is NOT under any tropical storm or hurricane threat, watch, or warning.
The Forecast
Thursday
ThursdayFriday
FridaySaturday
SaturdaySunday
SundayMonday
MondayMarine Forecast
Seas Forecast: Moderate Seas, Reduced Visibility
Temperatures
Generally, over the next five days, maximum highs and minimum lows are forecast to be fairly seasonal.
Saturday through Tuesday
Low: 22-24°C
High: 29-32°C
Maximum high temperatures are forecast to range between 29°C to 32°C with slightly warmer in urbanized areas and cooler across Tobago and eastern Trinidad. Minimum lows are forecast to remain near 22°C to 24°C in Trinidad and near 23°C to 25°C in Tobago, trending cooler in interior areas. The heat index will generally remain below 35°C.
Forecast Impacts
Flooding
FloodingLocalized street/flash flooding is possible, mainly on Friday and Saturday, associated with isolated heavy showers or thunderstorms.
Forecast Rainfall Totals
- Thursday: Less than 5 millimeters of rainfall accumulation across the country.
- Friday: Between 5 and 15 millimeters across the country, with higher accumulations up to 25 millimeters favoring southern and eastern coastal areas, as well as western coastal areas of Trinidad.
- Saturday: Between 5 and 15 millimeters across the country, with higher accumulations up to 25 millimeters favoring southern and eastern coastal areas, as well as western coastal areas of Trinidad. Locally higher totals are possible in thunderstorm activity.
- Sunday: Less than 5 millimeters of rainfall accumulation across the country.
- Monday: Little to no rainfall is expected in most areas. Less than 5 millimeters of rainfall accumulation is forecast in isolated areas with brief, passing showers
Putting the rainfall forecast into context, rainfall rates in excess of 50 millimeters per hour or areas that receive in excess of 25 millimeters within an hour tend to trigger street flooding across the country or flash flooding in northern Trinidad. For riverine flooding to occur, a large area of the country (not just in highly localized areas of western coastal Trinidad) would have to record upwards of 75 millimeters within 24 hours, and rainfall would have to fall across major rivers’ catchment areas.
Strong Thunderstorms
Strong ThunderstormsGusty Winds
Gusty WindsPossible impacts include localized wind damage to trees, power lines, and small structures. 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.
Other Hazards
Saharan Dust Forecast
Major Saharan Dust Surge Now Moving Across T&T
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.
On Friday and Saturday, isolated to scattered rainfall is forecast. Otherwise, highly isolated showers are forecast, interrupting sunny and hazy skies.
Forecast Discussion
A persistent western Atlantic high-pressure system is forecast to remain in place, while Trinidad and Tobago remains on the southern periphery of the ridge, with a confluent pattern developing overnight through Thursday, combined with a weak low-level trough. However, a dry airmass will inhibit showers on Thursday across the Windwards and Trinidad and Tobago.
By Thursday night, low-level convergence trailing the passage of this weak trough is forecast to begin producing cloudiness with widely scattered showers.
On Friday and through Saturday, a surge of deep-layered moisture associated with yet another low-level trough is forecast to move across Trinidad and Tobago, with an increase in cloudiness, rain, and showers throughout the day.
A mid- to upper-level trough axis, west of the Lesser Antilles, is also forecast to enhance unstable conditions and convection across Trinidad and Tobago. However, wind shear will be roaring across the islands during this period, up to 80 knots, significantly inhibiting strong convection and limiting persisting heavy rainfall.
Conditions are set to become increasingly stable on Sunday into Monday, as dry airmasses at both the upper and low levels move in. Saharan Dust levels are also set to increase from Monday, leading to increasingly hazy skies.
March 2023’s Climate
March 2023 has been unusually dry across Trinidad and Tobago. Only three of the last 29 days recorded measurable rainfall at Piarco, while at Crown Point, four out of the 29 days of March to date recorded rainfall. As rainfall records stand on March 29th, Piarco ranks in the top five driest months for the last 40 years while Crown Point, which has been slightly wetter, ranks as the 11th driest since 1980.
While rains will be a welcome respite from the prevalent dryness, heavy rain on burn scars and very dry soil will lead to increased surface runoff and an elevated potential for flash floods. In addition, with the Friday-Saturday rainfall event shaping up to be the first notable rainfall event for the year, drains may be clogged by garbage, leading to an elevated potential for street flooding.
Rainfall on Friday into Saturday is not expected to be a widespread, high-impact event, but localized flooding may lead to traffic disruptions in some places. If you live in a flood-prone area, use this as a dry run for preparations for the Wet Season to ensure your surroundings are clean and drains on your property are clear.
