We’re tracking several tropical waves east of the Lesser Antilles, with three forecast to affect Trinidad and Tobago over the next five days. At this time, none are showing signs of organization, and tropical cyclone formation is not forecast in the Atlantic Basin over the next seven days.
What you need to know
— Tropical Wave 05: The axis of this tropical wave is located along 52W on Friday afternoon, moving west at 10 knots (18 KM/H). This wave is forecast to move across Trinidad and Tobago Saturday evening through Sunday morning.
— Tropical Wave 06: The axis of this tropical wave is well-defined, located along 42W on Friday afternoon, moving west at 10 knots (18 KM/H). It is forecast to move across Trinidad and Tobago during the second half of Sunday into Monday morning.
— Tropical Wave 07: The axis of this tropical wave is located along 35W on Friday afternoon, moving west at 15-20 knots (27-37 KM/H). This tropical wave is forecast to move across T&T on Monday into Tuesday, with strong winds likely along the northern portion of the wave axis, mainly north of T&T.
— Tropical Wave 08: This tropical wave has just moved off the African coast, located along 22W on Friday afternoon, moving west at 10 to 15 knots (18-27 KM/H). Forecast models indicate this wave is set to move across the region by next Thursday.
— Hazards: From Saturday afternoon through Wednesday morning, periods of rain, moderate to heavy showers, and isolated to scattered thunderstorms are forecast to affect Trinidad and Tobago as a result of these tropical waves interacting with the Intertropical Convergence Zone. Flooding and landslide concerns will be increasing, particularly by Tuesday.
Tropical Wave 05
The fifth tropical wave analyzed by the National Hurricane Center is located approximately 750 kilometers east of Trinidad and Tobago, along 52W, and moving west at 10 knots (18 KM/H). The tropical wave is producing scattered showers and thunderstorms, with significant dry air located ahead of the wave, mainly to the wave’s northwest.
Across the wave axis, total precipitable water (TPW) values, which measure atmospheric moisture, are high, between 2.5 and 3 inches. Wind shear is generally light and favorable ahead of the tropical wave, and sea-surface temperatures are record-warm.
Forecast models indicate favorable low-level and upper-level conditions as this tropical wave nears Trinidad and Tobago. This will lead to cloudiness, isolated showers, and isolated thunderstorms ahead of the wave on Friday night into Saturday morning and again from late morning Saturday through the afternoon. This tropical wave will be the first of three waves, bringing the Intertropical Convergence Zone across Trinidad and Tobago and keeping a very moist environment across the country for the next four to five days.
Tropical Wave 06
The sixth tropical wave analyzed by the National Hurricane Center is located approximately 1.850 kilometers east of Trinidad and Tobago, along 42W, and moving west at 10 knots (18 KM/H). The tropical wave is producing scattered to widespread showers and thunderstorms, particularly where it interacts with the Intertropical Convergence Zone.
This tropical wave is forecast to move across Trinidad and Tobago on Sunday evening into Monday morning. Forecast models show cloudy skies with scattered pockets of rainfall, showers, and thunderstorms as this wave interacts with the Intertropical Convergence Zone, with fairly favorable low and upper-level conditions, in a low-shear, high-moisture environment.
Flooding concerns will begin to rise from Sunday, mainly across eastern and southern areas, where 36-hour rainfall totals nearing 75 millimeters are likely in the aforementioned areas with isolated higher totals. Additionally, following the passage of this wave, low-level winds are forecast to increase.
Tropical Wave 07
The seventh tropical wave, not yet analyzed by the National Hurricane Center for the 2024 Atlantic Hurricane Season, has caught our attention. Forecast models indicate conditions remain favorable for this wave to strengthen (not develop) as it nears the Windward Islands on Monday through Tuesday of next week.
Update 5:30 PM – The National Hurricane Center has added the 7th tropical wave for 2024 to its surface pressure analysis along 33W as of their analysis at 2:00 PM.
With stronger tropical waves, we see a low-level jet develop along the northern portion of the wave axis, with stronger winds making it to the surface in heavy showers and thunderstorms. Additionally, at the time of this wave’s passage, mid- to upper-level conditions are forecast to be very favorable, supporting deeper convection (showers, thunderstorms) with a light wind shear and high moisture environment.
As a result, the potential for heavy rainfall across multiple areas across Trinidad, Tobago, and the Windward Islands exists. With the Intertropical Convergence Zone also present, as well as rainfall from the prior few days, flooding concerns will be elevated. If you live in flood-prone areas of southern and eastern Trinidad, this may be your first flood event for the 2024 Wet Season. However, soils remain quite dry following a harsh Dry Season, so widespread flooding, or even prolonged flooding, is not expected.
By Wednesday, overall rainfall accumulations across the eastern and southern halves of Trinidad are forecast to range from 50 to 150 millimeters. Across the west-central, northwestern, and north-central regions of Trinidad and Tobago, between 25 and 50 millimeters of rainfall is forecast, with isolated higher totals.
The next tropical wave, also not analyzed by the National Hurricane Center at this time, is forecast to arrive across the region by next Thursday. However, a surge of dry air following Tropical Wave 07 will limit rainfall across T&T.
Not Every Tropical Wave Brings Severe Weather
Tropical waves vary in intensity as they travel westward across the Atlantic. This variability can be in the order of days or as short term as hours. Sometimes, you may see satellite imagery that shows heavy thunderstorms and deep convective activity east of Trinidad and Tobago during the late night and early morning, but by daybreak – nothing.
This is due to diurnal (daily) variations in convective showers whereby convection peaks overnight and wanes during the day for already occurring convective systems (i.e., not triggered by daytime heating).
Activity can be enhanced by its proximity to upper-level troughs and the ITCZ but can also be degraded by hostile upper-level conditions and Saharan Dust.
