The Meteorological and Geophysical Bureau (SMG) said in a special weather warning last night that it was unlikely that hail would fall again, after an extremely rare hailstorm hit Macau at around 9 p.m. yesterday.
Hail is a form of solid precipitation, consisting of balls or irregular lumps of ice, each of which is called a hailstone.
By 1 a.m. today there were no reports of any damage caused by the hailstorm in Macau.
The observatory issued a Red Rainstorm Warning Signal at 9:10 p.m., with strong winds and thunderstorms, minor flooding in some low-lying areas due to slow drainage, and waterlogging at some construction sites.
The Red Rainstorm Warning Signal is the second-highest of a three-level warning system, between Black at the highest and Yellow as the lowest.
Red means that “heavy rain has fallen or is expected to fall over extensive areas, exceeding 50 millimetres in an hour, and is likely to continue,” according to the bureau.
At 9:37 p.m. yesterday, the weather station said the convective rainstorm area had moved away and the rain continued to ease, so the Red Rainstorm Warning Signal was lowered to the Yellow Rainstorm Warning Signal at 10: 20 p.m. and dropped completely at 23:50 p.m., while the Thunderstorm Warning was lowered at 00:20 a.m. today, when the rain was expected to subside.
Convective storm is the scientific term for severe thunderstorms, including heavy rainfall, strong winds, hail and tornadoes. Convection is the vertical movement of heat and moisture, especially by updrafts and downdrafts in an unstable air mass. According to Wiktionary, the terms convection and thunderstorm are often used interchangeably, although thunderstorms are only one form of convection.
However, the observatory stated on its website that under the influence of a trough of low pressure, there will be showers, heavy at times, today and tomorrow.
Considering the possibly extreme weather conditions affecting Macau today and tomorrow, the bureau urged the public to take shelter in a safe indoor place and to pay close attention to the weather conditions and the latest news from the education authorities to guard against possible damage and when driving beware of the impact of strong wind.
Meanwhile, the Hong Kong Observatory warned last night that hail could affect the city after it was reported in the Pearl River Delta, including Macau. It called on the public to be alert and seek safe shelter, as violent gusts reaching 110 kilometres per hour were affecting Hong Kong last night.
This photo downloaded from a social media platform shows last night’s hailstorm in Macau.
