New categories introduced for severe, super typhoons

A new executive order concerning typhoons and tropical storms has come into effect, introducing two new categories for the most extreme forms of the weather phenomenon: the “severe typhoon” and the “super typhoon”.

According to Executive Order 61/2018, a “severe typhoon” occurs when the maximum sustainable wind speed near the tropical storm center is between 150 km/h to 184 km/h, and a “super typhoon” occurs at a wind speed of 185 km/h or greater.

The government has also updated its guidelines for the public in the event of extreme typhoons. It advises the suspension of all outdoor and marine activities, and recommends that the public stay indoors as far as possible, avoiding exposed doors and windows.

Should Macau lie directly in the typhoon’s path, it is possible that the center of the storm – marked by a sudden lull in wind speed – will pass through the city.

“A temporary lull means that the tropical cyclones is centered nearby and a sudden resumption of violent winds is expected. The places that were sheltered from the strong winds originally may become exposed,” the executive order reads. “The public is advised not to relax their guard and [to] pay close attention to the latest message of tropical cyclone.”

The Macau Meteorological and Geophysical Bureau notes on its website that when Signal No.10 is hoisted, “reinforced defense should be applied [in preparation] for severe typhoons and super typhoons.”

In the event of a severe or super typhoon, the latest information regarding the weather forecast will be provided via the internet and social media.

Separately, four new names have been introduced to the list of tropical cyclones in the western North Pacific and the South China Sea, according to a statement published on the Hong Kong Observatory website. The new names are Nyatoh, Trases, Mulan and Hinnamnor, replacing the old names Meranti, Sarika, Haima and Nock-ten respectively.

The names were selected for 2018 by the contributing countries of Malaysia, Cambodia, China and Laos and are named after plant and animal species and a national protected area in the case of the latter.

The new names were endorsed by the United Nations Economic and Social Commission for Asia and the Pacific/World Meteorological Organization Typhoon Committee at its 50th session held in the Vietnamese capital of Hanoi.

According to convention, the Typhoon Committee considers retiring the names of tropical cyclones that cause serious human casualties and economic loss.