Ashfall in Barbados’ Atlantic Shores on Saturday night, 10th April 2021 (Michael Watkins)
|Present La Soufrière Alert Level:||ORANGE||There is a highly elevated level of seismic and/or fumarolic activity or other unusual activity. An eruption may begin with less than twenty-four hours’ notice.|
Starting at the source of the eruption, St. Vincent and the Grenadines (SVG) Meteorological Service has issued a weather warning to “take action to protect life and property.” According to the SVG Met. Service, “moderate concentrations of Saharan dust and ash clouds are spreading from volcanic plumes of the ongoing explosive eruption at La Soufrière St. Vincent, contribute to overcast skies with very poor visibility and unhealthy air quality.” In addition, volcanic lightning and thunder are likely across St. Vincent, lessening toward the Grenadines.
Communities across Sandy Bay, St. Vincent are grappling with the impact of the #LaSoufriere eruption, as the weight of volcanic ash cause roofs to collapse across the area. https://t.co/bqEM6wc1l3 pic.twitter.com/ooXxZkYJXl— TTWeatherCenter (@TTWeatherCenter) April 10, 2021
For St. Vincent and the Grenadines, a marine warning is also in effect as long-period waves are likely to cause life-threatening surf and rip-currents across SVG by Monday. Hence, small-craft operators and sea-bathers should exercise extreme caution and take action to protect life and property due to very poor visibility and air quality.
The St. Lucia Meteorological Services have also issued a volcanic ash advisory for the island. Presently La Soufrière’s ash cloud is mostly affecting Barbados because of this mid to upper-level flow. Due to the close proximity of St. Vincent, it is expected that some small amount of ashfall will occur over the southern part of Saint Lucia. Residents are asked to take the necessary precautions as outlined by St. Lucia’s National Emergency Management Organization.
Heavy ashfall ongoing at Saint John, Barbados as plumes of volcanic ash from #LaSoufriere drift across the island. Visibility is below 1 kilometer.— TTWeatherCenter (@TTWeatherCenter) April 10, 2021
Video: Pat All Brewhttps://t.co/lc2Kv7P4PG pic.twitter.com/2YhuFr9Wqc
Barbados has been experiencing severe ashfall. The Barbados Meteorological Service (BMS) has issued both a Severe Volcanic Ash Warning and a Small Craft Warning for Barbados. A thick plume of volcanic ash from the La Soufrière Volcano in St. Vincent is currently affecting the island. A Small-Craft Warning is issued when reduced visibility (less than 5 kilometers) affects the marine area.
Periodic explosive eruptions from the La Soufriere volcano in St. Vincent continue to send thick plumes of ash traveling eastward towards Barbados. There have been observations and reports of ashfall across the island throughout the last 48 hours. Saharan dust haze also remains present across the island, which will continue to reduce visibility. These adverse conditions are expected to continue to affect Barbados with variations in intensity, and as a result, the Barbados Meteorological Service has issued and extended the Volcanic Ash Warning.
#LaSoufriere’s volcanic ash continues to fall at Lauriston, Carriacou. This is one of Grenada’s dependencies, an island north of Grenada and south of the Grenadines.— TTWeatherCenter (@TTWeatherCenter) April 11, 2021
Video: KOMG Productionshttps://t.co/lc2Kv7P4PG pic.twitter.com/OvUErq2tzt
Ashfall has made its way to Grenada and its dependencies overnight Saturday 10th April 2021 through Sunday 11th April 2021. The Grenada Met Office has received reports of ash-like particles on vehicles, vegetation, and buildings throughout the state of Grenada and has issued a Volcanic Ash Advisory. According to their Met Office, “while the forecast is for the ash to move off to the east and northeast of St. Vincent, it is possible for minute ash particles to spread southward and deposit over Grenada. These small and light particles can be carried over Grenada by the low-level winds as they descend through the atmosphere. Ash deposition is likely to increase with periods of precipitation especially across northern parts of the state.” A marine advisory is also in effect for Grenada’s waters as “a combination of Volcanic ash and Saharan dust is expected to reduce visibility.”
#LaSoufriere's ashfall has made it to mainland Grenada, with ash being reported at Sauteurs, St. Patrick, Grenada.— TTWeatherCenter (@TTWeatherCenter) April 11, 2021
This follows ashfall overnight on Grenada's dependencies of Carriacou and Petit Martinique.
Photos: Grenada Broadcasting Networkhttps://t.co/lc2Kv7P4PG pic.twitter.com/Z58rDJ7qRO
For the aviation industry, regular “Volcanic Ash Advisories” and “Significant Meteorological Information” are being issued by the Washington DC Volcanic Ash Advisory Center and the Trinidad and Tobago Meteorological Service, respectively. Barbados and St. Vincent’s airports have been closed at least until Monday 12th April 2021.
For mariners, an “Ashfall Advisory” is in effect for the marine waters surrounding St. Vincent and extending as far east as east of Barbados from the National Hurricane Center Tropical Analysis and Forecast Branch. Mariners are encouraged to contact the National Hurricane Center at 305-229-4424 if they encounter volcanic ash or floating volcanic debris.
Can La Soufrière’s ashfall impact T&T?
For ash to travel southward, winds will have to originate from the north. This is a highly unusual circumstance only seen when powerful low-pressure systems such as tropical cyclones move across the region, influencing wind speeds and directions across the Windward Islands.
Through the next 14 days, models indicate mostly easterly winds below the 500 millibar level and mostly westerly to southwesterly winds above the 500 millibar level. Hence the islands most at risk for ashfall remain, St. Vincent, St. Lucia, Barbados, and Martinique. If winds at the mid to upper levels of the atmosphere shift toward the south-southwest, ashfall will be possible across Grenada’s dependencies including Carriacou and Petit Martinique, as well as several small, largely uninhabited islands. This occurred overnight from Saturday 10th April 2021 into Sunday 11th April 2021.
Similarly, as ash drifts further and further southeast over time, it is possible eastern areas of Tobago experience some ashfall by next week (April 12th-19th). For Trinidad, it still remains highly unlikely ash may travel as far south as the island. If an ash cloud does drift this far south, it will be highly dispersed in the upper atmosphere, remaining mainly an aviation hazard with little to no impacts on the ground.