— Scattered showers and thunderstorms are likely to begin across both islands this afternoon, with intermittent showers through the next 36 hours into Tuesday as Tropical Wave 17 forecast to move across T&T.
— Favorable atmospheric conditions are in place to support thunderstorms, particularly during the first half of Tuesday.
— Gusty winds up to 60 KM/H are possible. Locally heavy rainfall, favoring Northeastern and Coastal Eastern Trinidad, as well as Tobago may trigger street and even flash flooding. Landslides and downed trees are possible in elevated areas. Severe weather is possible. Much of the “inclement” weather is forecast to occur overnight into early Tuesday.
— A mild surge of Saharan Dust is forecast to follow late Tuesday into Wednesday, reducing air quality to moderate.
— As of 10:45 AM Monday 8th July 2019 – There are no alerts, watches or warnings in effect for T&T from the Trinidad and Tobago Meteorological Service
Tropical Wave 17
The axis of this wave extends along 54W/55W from 15N southward. Widely scattered moderate to isolated strong rain showers are from 07N to 12N between 48W and 60W.
This wave is embedded within the ITCZ. It is forecast to bring a surge of moisture across Trinidad, Tobago and the Windwards by this afternoon, over the next few hours into Tuesday, dragging the ITCZ over T&T. Favorable upper-level conditions will support moderate to locally strong convection (thunderstorms), particularly overnight into the first half of Tuesday.
On Monday afternoon through late Tuesday, Trinidad and Tobago will see an increase in cloudiness, showers, and thunderstorms. Much of the heaviest activity is forecast to occur on Tuesday, with moderate to rough seas, flooding (street and flash flooding), gusty winds and landslides. Note that this wave will be similar to prior inclement weather events for the year as a result of the passage of a tropical wave.
Regardless, an adverse weather advisory (either an alert/watch/warning) may be issued for Trinidad and Tobago from the Trinidad and Tobago Meteorological Service, at models continue to trend towards inclement weather on Tuesday.
Tropical Wave 17 Forecast – What to Expect
Note: Street/Flash flooding, frequent lightning, gusty winds, landslides/mudslides are all possible beginning during the afternoon on Monday through late Tuesday (5:00 PM). In addition, locally severe thunderstorms may produce isolated areas, up to 50 millimeters of rainfall, across eastern parts of Trinidad and Tobago
Models are more in agreement this morning with the potential impacts over the next 24-36 hours across Trinidad and Tobago.
Second Half of Monday (12:00 PM Monday through 12:00 AM Tuesday): Increasing cloudiness and showers as the afternoon progresses, with intermittent showers across both islands. Eastern Trinidad, Tobago has the highest chances of experiencing heavy showers and thunderstorms.
First Half of Tuesday (12:00 AM Tuesday through 12:00 PM Tuesday): Intermittent and scattered, to widespread showers and thunderstorms are likely through the first half of Tuesday. Activity will be similar to previous tropical waves where heavier showers and thunderstorms are isolated and locally heavy rainfall is forecast mainly across Eastern Trinidad.
Second Half of Tuesday (12:00 PM Tuesday through 12:00 AM Wednesday): A few isolated showers and thunderstorms are likely through the early afternoon, favoring Trinidad, becoming more settled as the day progresses. A mild surge of Saharan Dust is likely to begin moving across T&T by the late evening into the night.
Showers and thunderstorms are forecast to become more sparse throughout the day on Tuesday, with severe thunderstorms south of Trinidad, along Coastal Venezuela. Upper-level clouds may produce a partly to mostly cloudy day across Trinidad and Tobago.
Possible Impacts to Trinidad and Tobago
Locally Heavy Rainfall & Flooding: Based on the 0Z and 6Z Monday model runs, from Monday (2:00 PM) through Wednesday (2:00 AM), generally, over the 36 hour period, models are in agreement of less than 20 millimeters across Western half of Trinidad and between 20-40 millimeters across the Eastern half of Trinidad as well as all of Tobago. Isolated rainfall totals up to 60 millimeters are possible across Northeastern Trinidad, as well as parts of Tobago.
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.
Frequent Lightning: In addition, with thunderstorms, frequent lightning is likely. Thunderstorms are forecast to occur mainly after 10:00 PM Monday.
Gusty Winds: Gusty winds, generally up to 60 KM/H are likely. Gusty winds are most likely prior to, in the vicinity of, or occur during heavy showers or thunderstorms. With wind gusts up to 60 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: In landslide-prone areas, particularly in areas that receive heavy rainfall, landslides and/or mudflows may occur. These landslides, in addition to gusty winds, may down trees, utility poles and impede traffic on roadways.