The Hazardous Seas Alert
The Trinidad and Tobago Meteorological Service has updated the Hazardous Seas Alert for all coastlines of Trinidad and Tobago, with the exception of the southern coastline of Trinidad. The alert goes went into effect at 11:00 AM Sunday, October 27th, 2019 now through 2:00 PM Monday 4th November 2019. This is in line with much of the global wave modeling. We mentioned the possibility of this extension in a prior update. Note that wind-driven waves will produce moderate to at times rough seas later next week due to a surge of trade winds.
Trinidad and Tobago is NOT under any tropical storm threat, watch or warning.
Based on the latest model guidance and analysis, long period swells are ongoing through next Monday. The effects will be exacerbated by ongoing spring tides. Elevated tides are ongoing due to New Moon occurring on Sunday 27th October, with elevated tides ongoing through October 31st.
These swells are originating from a large low-pressure system, in the Central North Atlantic Ocean.
Generally, battering waves in nearshore areas are forecast to begin on Sunday, particularly during high tide periods. Coastal flooding is also likely in low-lying coastal areas, which will be enhanced by Spring Tides. Beach and coastal erosion are likely, particularly along Northern and sheltered coastlines. Overall, there is a high risk of rip currents and large waves at beaches through next Saturday, so disruptions to beachgoers and marine interests are expected.
Information from the Trinidad and Tobago Meteorological Service concerning the Hazardous Seas Alert for October 27th to November 4th, 2019
“Long-period north-easterly swells are affecting nearshore activity in northern, sheltered and to a lesser extent eastern coastal areas. Effects are usually in the form of occasional battering waves, which can lead to disruption to sea bathing and other nearshore coastal activities. Mild coastal flooding and damage/erosion are also possible. Spring tides are also in effect, which will enhance near-shore impacts during high tides. A peak in the swell event is expected between Wednesday evening and Thursday morning. As such, the above effects can be exacerbated and more in-land areas can be directly impacted with higher surfs.” according to the Trinidad and Tobago Meteorological Service. This “alert” status takes into account the possibility of the event occurring. This hazardous seas event is ongoing.
The color of the alert indicates the severity of the event and the probability of the event occurring. Currently, the alert level is at Yellow. This means that the hazard is observed and you need to be aware of the impacts of hazardous seas in your area. Moderate impacts are expected, so there is the chance of possible injuries and persons would need to take action to ensure safety. There may be minor damage to property.
Sea Conditions For The Next 7 Days
The Takeaway: Based on the latest model guidance and analysis, long period swells are forecast through next week, beginning on Sunday and lasting through next Monday. Spring Tides are forecast to subside by Thursday. A Hazardous Seas Alert is now in effect until 2:00 PM Saturday.
During high tide periods, as noted below, coastal flooding is likely along Mosqutio Creek, Guayaguayare and other low-lying coastal areas. The initial peak occurred on Sunday night through Monday, and the second peak is forecast again on Thursday night into Saturday.
Peak Spring Tides occurs from Saturday 26th October to Thursday 31st October.
Approximate high tides for Trinidad and Tobago are seen below. Mosquito Creek can expect coastal flooding during these times, particularly 30 minutes prior and 30 minutes after when peak high tides occur. Similar conditions are forecast elsewhere during these high tide periods in low-lying coastal areas throughout the week.
On days where localized, afternoon, thunderstorms and heavy showers occur, mainly across Western Coastal Trinidad, onshore winds resulting from this activity may exacerbate coastal flooding.
The general sea state throughout the week is as follows:
AM Wednesday 30th Oct. – PM Thursday 31st Oct.: Slight to Moderate, with waves generally between 1.5 meters to 2.0 meters in open waters, occasionally above 2.0 meters. In sheltered areas, near 1.0 meters but choppy. Long Period Swells ongoing.
PM Thursday 31st Oct. – PM Monday 4th November (beyond the expiration of the Hazardous Seas Alert): Moderate, with waves above 1.5 meters, up to 2.0 meters and occasionally up to 2.5 meters, particularly in Eastern Coastal waters on Saturday into Sunday. In sheltered areas, near 1.0 meters but choppy. Long Period Swells to subside by late Monday.
PM Monday 4th November – PM Thursday 7th November: Moderate to occasionally Rough. Though the long period swells are forecast to subside, a surge in easterly trade winds is forecast to whip up wind-driven waves with waves between 2 meters to 2.5 meters in open waters, with Eastern coastlines particularly affected.
Impacts to T&T’s Shorelines
High tides combined with onshore wind and swell actions could result in localized coastal flooding and beach erosion.
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.
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 surfs can knock spectators off exposed rocks and jetties. Breaking waves may occasionally impact harbours making navigating the harbour channel dangerous. This may be exacerbated during the afternoon, localized thunderstorms and heavy showers across Western coastal Trinidad.