Tropical Storm Bret: Tropical Storm Warning Issued For St. Lucia

Tropical Storm Bret continues to move westward toward the central Lesser Antilles on Wednesday, with a bout of strengthening over the last 12 hours.

While Tropical Storm Bret poses no direct threat to Trinidad and Tobago at this time, periods of showers and thunderstorms associated with outer bands and influenced convergence from Bret are forecast from Wednesday evening through Friday night across and near the country.

What you need to know

What has changed: Bret has strengthened with sustained winds up to 95 KM/H and higher gusts, with the tropical-storm-force wind radii increasing to 95 KM, mainly north of the center. Bret has slowed somewhat down to 22 KM/H. An Air Force Hurricane Hunter is en route to investigate the system.
Where is it forecast to move: Forecast models have honed in on the center of circulation moving across the central Lesser Antilles near St. Lucia and Martinique, well north of Trinidad and Tobago.
The Intensity & Impacts: The current forecast track places islands northward of St. Vincent and Barbados and southward of Dominica at the highest risk for damaging winds, flooding rainfall, storm surge, and hazardous seas. The National Hurricane Center’s forecast calls for a tropical storm with sustained winds up to 100 KM/H and gusts to 120 KM/H moving across the central Lesser Antilles. For the southern Windwards, southward of St. Vincent and the Grenadines, as well as Barbados to Trinidad and Tobago, feeder bands could extend southward, bringing showers/thunderstorms and gusty winds. In addition, light to near-calm winds will lead to increased daytime temperatures, localized, slow-moving afternoon showers and thunderstorms, and agitated seas mainly on Thursday, with increased winds from the southeast on Friday.
Latest from officials: A Tropical Storm Warning is now in effect for St. Lucia. Tropical Storm Watches are in effect for Barbados, Dominica, and Martinique, with additional watches or upgrades to warnings likely later today.

The latest

Forecast cone for Tropical Storm Bret as of 11:00 AM Wednesday, June 21st, 2023. While the forecast cone is meant to capture where the center of circulation is forecast to track 66% of the time, impacts can extend well beyond this cone. (National Hurricane Center)

At 11:00 AM Wednesday, June 21st, 2023, Tropical Storm Bret’s approximate center of circulation was located at 13.0°N and 52.5°W, placing the center approximately 930 kilometers east-northeast of Tobago and 760 kilometers east of Barbados.

According to the National Hurricane Center’s 11:00 AM Advisory, Tropical Storm Bret is moving west at a brisk pace of 22 KM/H, and this is forecast to continue for the next several days, approaching the Lesser Antilles by Thursday afternoon into the night with an increase in forward speed expected.

Maximum sustained winds have increased to 95 KM/H with gusts to 105 KM/H, with some strengthening before this system reaches the Lesser Antilles. The NHC says this system is forecast to remain a tropical storm as it moves across the Lesser Antilles, with weakening forecast thereafter in the Caribbean Sea, likely dissipating by Saturday. The current minimum central pressure is 1001 millibars, with tropical storm-force winds extending outwards up to 95 kilometers from the center.

Tropical Storm Bret east of the Lesser Antilles on Wednesday, June 21st, 2023 (Weathernerds.org)
Tropical Storm Bret east of the Lesser Antilles on Wednesday, June 21st, 2023 (Weathernerds.org)

Current Watches & Warnings

Current tropical storm watches and warnings for Tropical Storm Bret as of 11:00 AM Wednesday, June 21st, 2023.

A tropical storm warning is now in effect for St. Lucia. A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area within 36 hours.

Tropical storm watches are now in effect for the following countries:

  • Barbados
  • Dominica
  • Martinique

A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours.

Interests elsewhere in the Lesser Antilles should monitor the progress of Bret. Additional tropical storm watches or warnings will likely be required for other islands later today.

There are no alerts, watches, or warnings in effect for Trinidad and Tobago at this time from the Trinidad and Tobago Meteorological Service.

What could be the impacts?

Overall forecast impact level from the passage of Tropical Storm Bret

For Barbados and the central Lesser Antilles, tropical-storm conditions are possible on Thursday with sustained winds up to 100 KM/H, which can produce wind damage across the islands. Seas are forecast to become hazardous, with forecast rainfall totals likely to produce street/flash flooding and landslides.

South of St. Vincent, southward to Tobago (and to a lesser extent Trinidad), and north of Guadeloupe, feeder bands could produce periods of heavy rainfall and gusty winds which would be capable of producing localized wind damage, street/flash flooding, and locally rough/choppy seas.

For the remainder of the Leewards and westernmost Greater Antilles, little to no major impacts are forecast.

Wind

As mentioned above, the National Hurricane Center is forecasting, as of 11:00 AM Wednesday, June 21st, 2023, a tropical storm with sustained winds up to 100 KM/H and gusts to 120 KM/H moving across the French Antilles, mainly between St. Vincent and Dominica.

Certainty has increased in both track and intensity, with nearly all intensity models, in line with the National Hurricane Center’s forecast, showing a tropical storm at the time of Bret’s passage across the Lesser Antilles.

With weaker tropical cyclones, the stronger winds generally remain on the northern half of the system’s circulation, meaning St. Lucia, Martinique, Dominica, and even Guadeloupe, could see winds of tropical storm strength.

Forecast probabilities of the region experiencing tropical-storm-force winds according to the National Hurricane Center, as of 11:00 AM Wednesday, June 21st, 2023, associated with Tropical Storm Bret (Data: National Hurricane Center)
Forecast probabilities of the region experiencing tropical-storm-force winds according to the National Hurricane Center, as of 11:00 AM Wednesday, June 21st, 2023, associated with Tropical Storm Bret (Data: National Hurricane Center)

With feeder bands forecast to traverse much of the eastern Caribbean over the next 24-48 hours, the National Hurricane Center has much of the eastern Caribbean area, north of Trinidad and Tobago, under a low to medium probability of experiencing tropical storm-force winds, but higher probabilities now exist for the central countries of the island chain.

Forecast probabilities of the region experiencing hurricane-force winds according to the National Hurricane Center, as of 11:00 AM Wednesday, June 21st, 2023, associated with Tropical Storm Bret (Data: National Hurricane Center)
Forecast probabilities of the region experiencing hurricane-force winds according to the National Hurricane Center, as of 11:00 AM Wednesday, June 21st, 2023, associated with Tropical Storm Bret (Data: National Hurricane Center)

While the southern Windwards aren’t in the direct line of fire from Tropical Storm Bret at this time, outer bands from the tropical cyclone could still have strong showers and thunderstorms that produce tropical-storm-force wind gusts or sustained winds for brief moments – hence the risk is not zero.

Global models show higher winds remaining north of the southern Windward Islands, including Trinidad and Tobago. When strong low-pressure systems (strong tropical waves, tropical storms, or even hurricanes) move sufficiently north of T&T, the winds across Trinidad and Tobago become light to near-calm as the pressure gradient across the area slackens. By Friday, across Trinidad and Tobago, winds are forecast to increase from the southeast, with faster-moving showers and thunderstorms forecast.

Rainfall

Overall rainfall accumulations from the passage of Tropical Storm Bret as of 11:00 AM Wednesday, June 21st, 2023

Generally, rainfall totals associated with Bret are forecast to range between 75 and 150 millimeters (3-6 inches), with higher totals up to 250 millimeters (10 inches) along Windward facing coastlines near the center of circulation in the central Lesser Antilles – namely, from Barbados and St. Vincent and the Grenadines, northward to Guadeloupe. Isolated higher amounts are possible, but the fast-moving nature of Bret is forecast to limit persisting heavy rainfall and higher accumulations.

As mentioned above, feeder bands, convergence associated with Bret, and local topography could produce locally heavy rainfall totals that may trigger localized flooding and mudslides/landslides. Ultimately, all islands across the Lesser Antilles should remain on guard for some form of flooding rainfall associated with this tropical cyclone later this week, whether there is a direct impact or not.

Seas and Storm Surge

European model for seas on Thursday into Friday, June 22nd into 23rd, 2023 as a result of Tropical Storm Bret (Windy)
European model for seas on Thursday into Friday, June 22nd into 23rd, 2023 as a result of Tropical Storm Bret (Windy)

Similar to the rainfall totals, how agitated seas become and the level of storm surge is dependent on the strength of the tropical cyclone.

Forecast models are showing waves in open waters are forecast to exceed 2.5 meters (8 feet) and up to 3.5 meters (12 feet) near east-facing coastlines. For areas near the center, waves can reach as high as 4.5 meters (15 feet) near coastlines and up to 6.5 meters (21 feet) in open waters. These higher seas are forecast to remain well north of Trinidad and Tobago, with hazardous seas likely from St. Vincent and the Grenadines, as well as Barbados northward.

For Trinidad and Tobago

Latest Forecast

Trinidad and Tobago is NOT under any tropical storm or hurricane threat, watch, or warning at this time.

In nearly all forecast model guidance as of 11:00 AM Wednesday, June 21st, 2023, Bret’s center of circulation moves well north of Trinidad and Tobago.

As the system nears on Wednesday night into Thursday, convergence ahead of the tropical cyclone, with winds coming from the northeast to north, moves some of the outer bands across the southern Windwards and Trinidad and Tobago. Then, on Thursday, as the center tracks north of Barbados, showers and thunderstorms move across Trinidad, Tobago, and the southern Windwards from the south to the north, feeding into the circulation (feeder bands and localized climatic effects). By Friday into Saturday, southerly to southeasterly wind flow feeds into the tropical cyclone with showers and thunderstorms trailing, moving across Trinidad, Tobago, and the Windwards again.

On Thursday, due to slack to near-calm winds, localized climatic effects like daytime heating, sea breeze convergence, and orographic effects take over, producing slow-moving showers and thunderstorms that are enhanced by topography. These effects can trigger locally heavy rainfall, producing street/flash flooding, gusty winds, and other hazardous weather impacts in localized areas while most of the region experience sweltering temperatures.

Pay close attention to official forecasts in the coming days from your respective authorities. For Trinidad and Tobago, official forecasts and early warnings come from the Trinidad and Tobago Meteorological Service.

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