King Tides Ongoing Through Wednesday, Then Long Period Swells

Saltwater on the South Trunk Road at Mosquito Creek on October 17th, 2020 as King Tides cause some of the highest high tides for the year. (Prudent Roach)

King Tides, the highest high tides and lowest low tides for 2020, are ongoing across T&T as a result of a super new moon. This has resulted in minor coastal flooding in low-lying coastal areas of T&T.

Thankfully, the peak of this King Tide event is nearly behind us, as it was ongoing from October 16th through October 18th, though elevated tides will continue through the 21st. With light winds and seas slight, coastal impacts will be negligible though mariners should still exercise caution during high tide.

A long-period swell event is forecast to begin on Wednesday associated with a developing tropical cyclone north of the Lesser Antilles. These swells will predominantly affect our northern and western coastlines through the weekend and into next week. Low-level winds are also forecast to surge by the latter half of the week through the weekend.

There are no alerts, watches, or warnings in effect from the Trinidad and Tobago Meteorological Service as of 3:00 AM Sunday 18th October 2020.

Seas Forecast For Trinidad

Sea state forecast through the next 7 days, as slight to moderate seas are forecast, with long-period swells and king tides affecting the island. Note that sheltered areas include bays, beaches, and generally the Gulf of Paria and western areas of the Columbus Channel. Open waters are the Atlantic Ocean (Eastern Trinidad), the Eastern Columbus Channel (Southern Trinidad), and the Caribbean Sea (north of Trinidad).
Sea state forecast through the next 7 days, as slight to moderate seas are forecast, with long-period swells and king tides affecting the island. Note that sheltered areas include bays, beaches, and generally the Gulf of Paria and western areas of the Columbus Channel. Open waters are the Atlantic Ocean (Eastern Trinidad), the Eastern Columbus Channel (Southern Trinidad), and the Caribbean Sea (north of Trinidad).

The general sea state through the next 7 days is as follows:

Sunday 18th through Wednesday 21st October 2020: Slight. Light winds are forecast across the region, as a deep-layered low pressure develops and remains north of the Lesser Antilles, weakening the pressure gradient. Seas in open waters are forecast to be slight, generally below 1.25 meters. In sheltered areas, near calm, except in the vicinity of heavy showers or thunderstorms, where it can become locally choppy or rough.

King tides will continue, with the tidal range decreasing through Wednesday. Still, for those in nearshore areas and mariners, exercise caution during high tide periods. By Wednesday night, seas will begin to increase, becoming moderate in open waters and long period swells will begin to affect the northern coastlines of the island.

Winds are forecast to be generally below 10 knots from the east to southeast, with gusts to 15 knots.


Thursday 22nd through Saturday 24th October 2020: Moderate. Low-level winds will begin to increase across T&T, as swells from a developed tropical cyclone north of the Lesser Antilles begin to predominantly affect our northern and western coastlines. In open waters, generally northern and eastern areas, waves between 1.0 meter to 2.5 meters are possible and choppy conditions are forecast in sheltered coasts, with waves generally below 1 meter along with these areas.

Large, breaking waves will likely exceed that 1-meter mark along Northern and Western coastlines into the weekend, causing coastal flooding along our southwestern peninsula.

Winds are forecast to be fresh to strong, with winds up to 20 knots from the east, gusting between 25 knots to 30 knots, particularly on Saturday into Sunday.

Below are approximate high tides for Port of Spain, Trinidad. Low-lying coastal areas may experience coastal flooding when long-period swells are occurring, particularly 30 minutes prior and 30 minutes after peak high tides.

High Tide Forecast for Trinidad over the next 7 days as long period swells and slight to moderate seas forecast.
High Tide Forecast for Trinidad over the next 7 days as long period swells and slight to moderate seas forecast.

Seas Forecast For Tobago

Sea state forecast through the next 7 days, as slight to moderate seas are forecast, with long-period swells and king tides affecting the island. Note that sheltered areas include bays, beaches, and generally western coasts of Tobago. Open waters are the Atlantic Ocean (Eastern Tobago) and the Caribbean Sea (west of Tobago).
Sea state forecast through the next 7 days, as slight to moderate seas are forecast, with long-period swells and king tides affecting the island. Note that sheltered areas include bays, beaches, and generally western coasts of Tobago. Open waters are the Atlantic Ocean (Eastern Tobago) and the Caribbean Sea (west of Tobago).

The general sea state through the next 7 days is as follows:

Sunday 18th through Wednesday 21st October 2020: Slight. Light winds are forecast across the region, as a deep-layered low pressure develops and remains north of the Lesser Antilles, weakening the pressure gradient. Seas in open waters are forecast to be slight, generally below 1.25 meters. In sheltered areas, near calm, except in the vicinity of heavy showers or thunderstorms, where it can become locally choppy or rough.

King tides will continue, with the tidal range decreasing through Wednesday. Still, for those in nearshore areas and mariners, exercise caution during high tide periods. By Wednesday afternoon, seas will begin to increase, becoming moderate in open waters and long period swells will begin to affect the northern coastlines of the island.

Winds are forecast to be generally below 10 knots from the east to southeast, with gusts to 15 knots.


Thursday 22nd through Saturday 24th October 2020: Moderate. Low-level winds will begin to increase across T&T, as swells from a developed tropical cyclone north of the Lesser Antilles begin to predominantly affect our northern and western coastlines. In open waters, generally northern and eastern areas, waves between 1.0 meter to 2.5 meters are possible and choppy conditions are forecast in sheltered coasts, with waves generally below 1 meter along with these areas.

Large, breaking waves will likely exceed that 1-meter mark along Northern and Western coastlines into the weekend with possible coastal flooding in low-lying areas.

Winds are forecast to be fresh to strong, with winds up to 20 knots from the east, gusting between 25 knots to 30 knots, particularly on Saturday into Sunday.


Below are approximate high tides for Scarborough, Tobago. Low-lying coastal areas may experience coastal flooding when long-period swells are occurring, particularly 30 minutes prior and 30 minutes after peak high tides.

High Tide Forecast for Tobago over the next 7 days as long period swells and slight to moderate seas forecast.
High Tide Forecast for Tobago over the next 7 days as long period swells and slight to moderate seas forecast.

Impacts on T&T’s Shorelines

Impacts possible from long-period swells include the following:

  • Loss of life
  • Injuries
  • Sea search and rescue disruptions
  • Disruptions to sea transportation
  • Scarcity of seafood
  • Damage or loss of boats and fishing equipment
  • Disruptions to marine recreation and businesses
  • Economic losses
  • Coastal erosion
  • Disruption to outdoor and sporting activities
  • Disruption of transportation (air and especially sea)

There is also the potential for loss of life. There is a high risk of rip currents, strong currents that can carry even the strongest swimmers out to sea.

Rip currents are powerful channels of water flowing quickly away from the shore, which occur most often at low spots or breaks in the sandbar and near structures such as groins, jetties, and piers. If caught in a rip current, relax and float. Don’t swim against the current. If able, swim in a direction following the shoreline. If unable to escape, face the shore and call or wave for help.

There is also the potential for injuries to beachgoers; beach closures; localized disruptions to marine recreation and businesses and financial losses.

High tides combined with onshore wind and swell actions could result in localized coastal flooding and beach erosion.

High surfs can knock spectators off exposed rocks and jetties. Breaking waves may occasionally impact harbors making navigating the harbor channel dangerous.

Saltwater will likely splash onto low-lying coastal roads such as the South Trunk Road at Mosquito Creek, the Guayaguayare Mayaro Road at the Guayaguayare Sea Wall, and the Manzanilla-Mayaro Road. Bays and beaches may become inundated.

Coral reefs may experience increased stress and damages, in addition to localized beach erosion, particularly in areas where battering waves focus.

Facebook Comments