‘Gustnado’ Blow Off Roof In St. James, Trinidad

Gusty winds, dubbed a ‘gustnado,’ from brisk passing showers on Thursday ripped off a roof from a home in St. James, Trinidad.

According to the homeowner, who was not home when the gusty winds moved through, neighbors saw leaves and dust swirling “like a tornado,” before striking the house.

T&TEC and TTFS respond to the blown off roof in St. James
T&TEC and TTFS respond to the blown off roof in St. James

The owner explained beyond the loss of the roof, there was no other major damages. T&TEC responded to the incident and was able to restore supply to the house before the end of Thursday.

There were no other reports of damages in the area nor injuries.

What caused this?

Blown off roof in St. James
Blown off roof in St. James

A high-pressure system has been dominating conditions across T&T and the Eastern Caribbean, with the pressure gradient forecast to intensify this weekend.

Low-level convergence and an approaching low-level trough will keep moisture and instability across the Southern Windwards, allowing for more showers with gusty winds.

However, this particular wind-damage-event was caused by a “gustnado.” A gustnado is a short-lived, ground-based swirling wind that can form on the leading edge of a gust front associated with a downdraft of a shower or thunderstorm.

Diagram of a gustnado (Skybrary)
Diagram of a gustnado (Skybrary)

The downdraft winds then spread outward upon hitting the ground, causing a strong rush of wind at the surface. If there is enough instability, rotation may develop and a gustnado might form.

The gustnado spins upward from the ground, extending between 30 to 300 feet above the surface. However, the rotating column of air in a gustnado is not connected to the base of a cloud, making it different from a tornado.

The average gustnado lasts a few seconds to a few minutes, like a tornado does, but is relatively weak and brief. They may be accompanied by rain, but mostly just toss dust and small debris into the air. Gustnadoes can sometimes reach wind speeds between 60 to 80 mph, resulting in significant damage, similar to that of an EF-0 or EF-1 tornado.

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