Tropical Disturbance North of Tobago Being Monitored For Development

The National Hurricane Center has tagged an area of disturbed weather north of Tobago that is following Tropical Wave 60 for tropical cyclone development over the next five days as it moves into the Southwestern Caribbean.

If this system forms, it will be called Eta. To date, 2020 has produced 27 named storms – 1 named storm shy of tying the Atlantic single-season record of 28 named storms set in 2005

Tropical Wave 60 (Tropical Disturbance) Key Messages:
– This tropical disturbance has medium chances of development over the next 5 days as it moves west across the Lesser Antilles, with development likely across the Western Caribbean Sea.
For T&T: Active weather associated with this tropical disturbance will remain well north of the country. However, another approaching tropical wave will bring heavy rainfall to the region on Friday into Saturday. On Thursday, afternoon showers and thunderstorms are possible across Trinidad, with breezy conditions.

Tropical Wave 60: Medium Chances for Tropical Cyclone Formation

Tropical Weather Outlook as of 8:00 AM Thursday 29th October 2020

In their 8:00 AM Tropical Weather Outlook on Thursday morning, the NHC is monitoring, “A large area of disturbed weather moving from the tropical Atlantic across the Lesser Antilles and into the eastern Caribbean Sea is associated with a pair of tropical waves. Upper-level winds are expected to become more conducive for the development of this disturbance during the next couple of days, and a tropical depression could form over the weekend or early next week while the system moves westward across the central and western Caribbean Sea.

Presently, the NHC has given this tropical wave a low, 20%, chance of development over the next 48 hours and a medium, 60%, chance over the next 5 days.

What We Know

Tropical Wave 60 in the Atlantic, producing an area of scattered showers and thunderstorms. (Weathernerds)
Tropical Wave 60 in the Atlantic, producing an area of scattered showers and thunderstorms. (Weathernerds)

A tropical wave is along 64W from 20N southward moving west at 15 knots. Scattered moderate convection is noted within 60 nm both sides of the wave axis, including Puerto Rico. This wave is forecast to move into the western Caribbean Sea by this weekend, bringing gusty winds and thunderstorms with it.

Over the last several days, we’ve been keeping an eye on this (and the following wave) as inclement weather was possible for T&T. However, due to strong westerly wind shear, stronger showers and thunderstorms has remained to our north and east. Still, abundant moisture and low-level spin exist, associated with the southern portion of the wave, following the wave axis. This tropical disturbance is located in an area of favorable upper-level divergence and low-level convergence.

What We Forecast

Tropical Wave 60: Track

The tropical disturbance will generally progress west with active weather remaining to T&T’s north and east, moving across the Central and Northern Lesser Antilles. It is then likely to impact parts of Honduras and Nicaragua by mid-next week.

EPS (EMCWF Ensembles) showing up to 95% of model runs bringing at least a tropical depression into Nicaragua and Honduras mid-next week. (Weathermodels.com)
EPS (EMCWF Ensembles) showing up to 95% of model runs bringing at least a tropical depression into Nicaragua and Honduras mid-next week. (Weathermodels.com)

A surface to low-level ridge (high-pressure system), anchored in the northwestern Gulf of Mexico, is dominating the steering flow of Tropical Wave 60, moving this disturbance to the west. This movement is forecast over the next several days, taking the system over the Caribbean Sea through the weekend, moving it somewhat southwest into the southwestern areas of Central America.

On this track, little to no impacts are anticipated for Trinidad and Tobago.

Tropical Wave 60: Intensity

Several models continue to show an organized tropical storm to an organized hurricane moving into Central America by mid-week next week. No significant impacts are expected to T&T.

GEFS (GFS Ensembles) showing several model runs bringing a tropical cyclone with minimum pressures of at least a tropical storm or hurricane into Nicaragua and Honduras mid-next week. (Weathermodels.com)
GEFS (GFS Ensembles) showing several model runs bringing a tropical cyclone with minimum pressures of at least a tropical storm or hurricane into Nicaragua and Honduras mid-next week. (Weathermodels.com)

Dynamical model guidance on systems that have not yet formed has a difficult time showing the eventual track or intensity of undeveloped systems.

Still, all of the operational models from top global models (EMCWF, GFS, UKMET) shows this system developing next week. Up to 95% of ensemble runs from the EPS (European EMCWF ensembles) bring winds of tropical depression strength (20+ knots) into Central America.

This disturbance, as it crosses the Lesser Antilles, has produced and is forecast to produce significant rainfall mainly north of T&T. An additional 2-4 inches (50 to 100 millimeters) are possible across the Central Lesser Antilles, with isolated totals up to 6 inches (150 millimeters). Note that across Trinidad and Tobago, little to no widespread rainfall is forecast.

But this model shows…

Individual model runs are just one possible outcome from a myriad of outcomes. Weather does not always follow what is modeled, and even what may be forecast. Beware of individual model runs being posted on social media.

Always check the National Hurricane Center for the latest information for tropical cyclones and your local meteorological offices for country-specific advisories.

What should I do?

For those in Trinidad and Tobago, nothing. This system will remain north and east of the country resulting in mostly hot and sunny skies on Thursday. Still, a few late morning through afternoon thunderstorms are possible. See our forecast.

For those north of Barbados and St. Vincent and the Grenadines, follow the advice of your local meteorological offices as flood alerts, watches and warnings are in effect and could be issued over the next 24 hours.

If you are a risk-averse person, now is a good time to check your inclement weather, flood, or hurricane season plan, ensuring your preparedness supplies are not expired, stocked, and in a safe location.

The Office of Disaster Preparedness and Management has put together a comprehensive guide for preparing for the Wet and Hurricane Season.

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