SMG justifies long-lasting signal 8 due to Koinu’s strong winds despite small size

The Macao Meteorological and Geophysical Bureau (SMG) has justified the decision of keeping Typhoon Signal No. 8 hoisted for a total of 17 hours and 30 minutes based on the fact that Typhoon Koinu was “small but strong,” the bureau said in a press statement.

According to the report from SMG, “On the afternoon of October 8, when Koinu came within a 100-kilometer radius of Macau, some neighboring regions continuously recorded winds of level 8-10 on the Beaufort Scale. Koinu’s circulation area was very small, however, when an area of strong winds near the eye of the tropical system crossed Zhuhai’s Miaowan Island station, a maximum wind speed of level 14 on the same scale was recorded.”

According to the Royal Meteorological Society, the Beaufort Scale is “an empirical measure that relates wind speed to observed conditions at sea or on land. Its full name is the Beaufort wind force scale.”

Created by the Irish hydrographer Francis Beaufort, a Royal Navy officer (later Rear Admiral), while serving on HMS Woolwich in 1805, the scale is divided into 13 classes (zero to 12) and relates a relative wind speed in knots “usually averaged over 10 minutes by convention, and do[es] not capture the speed of wind gusts.”

As mentioned also by the Royal Meteorological Society as well as by the USA’s National Weather Service, “the scale starts with 0 and goes to a force of 12,” being used to estimate wind strengths.

As also noted by the Royal Meteorological Society, the Beaufort levels “do not reflect the wind speeds that you would feel on the ground. At 2 meters, wind speed may be only 50-70% of these figures.”

“The specifications [of the scale levels] are descriptions of likely observations on land or at sea, and the probable and maximum wave heights (in meters) are quoted for the open sea. The figure for sea state (on a scale from 0-9) is a shorthand way of describing the sea surface conditions to various users,” the same organization notes.

Level 0 is defined as “Calm” in “Sea like a mirror; smoke rises vertically” up to level 12 which is defined as “Hurricane” and explained visually as “Devastation. Air filled with foam and spray, very poor visibility.”

This level 12 is reached when the wind speeds reach or surpass 118 km/h or 64+ knots.

As mentioned by SMG in their preliminary report of the passage of Koinu, “Although typhoon Koinu brought considerable winds to the neighboring region, Macau remained outside its level 8 wind zone. The bridges and monitoring stations at Macau International Airport, generally recorded sustained winds level 7 to 8 [which equals to between 50 to 74km/h].”

The weather bureau added that the rain bands associated with Koinu continued to widely affect the Pearl River Estuary area until 9 a.m. on October 9 with several areas of Macau registering an accumulated precipitation exceeding 100mm. In some areas of Taipa and Coloane, the accumulated precipitation exceeded 200mm.

Damages were little to none

According to the Civil Protection Operations Centre (COPC) between 4:30 p.m. on October 8 and up to 9 a.m. on October 9 there were only 13 incident reports recorded. These mostly included lampposts, trees or other structures that were addressed by the COPC for being on the verge of collapsing or potentially posing a risk to the population. Two people have been rescued after being trapped for some time in an elevator although the causes of this malfunction are yet to be determined.

There were two people reported injured during this period but the injuries were due to causes unrelated to the typhoon. The victims were allegedly involved in a traffic accident while riding a motorcycle and have been treated at the Kiang Wu Hospital.

Only a few people (13) utilized the emergency shelters set up by the Social Welfare Bureau as, on this occasion, the COPC did not evacuate anyone from the low-lying areas of the city since there was no threat of a severe flood.

According to figures released by the aviation authority, a total of around 150 flights have been canceled at the Macau International Airport as well as 22 flights delayed and 50 that have been rescheduled.

Evacuations ordered as remnants of Typhoon Koinu hit southern China

People have been moved to shelters and nearly 2,000 boats recalled to port as the remnants of Typhoon Koinu slammed into southern China yesterday after leaving one dead and over 300 injured in Taiwan.

The storm bore down on the southern Chinese island province of Hainan yesterday.

The Hong Kong Observatory said on its website that Koinu was weakening from a typhoon into a tropical depression as it moved southwest along the coast of China’s Guangdong province.

Air and rail services have been suspended as Koinu, meaning puppy in Japanese, rolled into the region.

Koinu arrived a month after southern China, Hong Kong and Macau were lashed by Typhoon Saola, which triggered Hong Kong’s highest storm signal on a scale of 11. A week later, Guangdong province and Hong Kong were hit with the heaviest rains in almost 140 years.

The storm also broke a windspeed record off Taiwan’s east coast, which faces the Pacific Ocean.

Ferry services connecting Hainan with mainland China, as well as ferry services between Hong Kong and Macau, were also suspended as Koinu moved across the island.