Summer heatwave set to soar in at 33 degrees after year's first Red rain

Following a week of turbulent weather that brought the city's first red rainstorm of the year, Hong Kong is set to experience a prolonged period of hot weather as a system of strengthening high pressure brings sunny skies and temperatures climbing to a scorching thirty-three degrees Celsius next week.

A swift transition to searing summer heat

According to the latest nine-day weather forecast from the Hong Kong Observatory, an atmospheric high-pressure ridge situated over the northern South China Sea is gradually strengthening. 

This system is expected to blanket the coast of southern China from the weekend through to the middle of next week, bringing clear skies and sustained hot weather to Guangdong. 

Starting Friday, Hong Kong is projected to experience nine consecutive days with maximum temperatures exceeding 30 degrees. 

This sharp turn in weather follows the departure of an upper-air disturbance that has plagued the region.

Forecasters noted that a gentle southerly airstream is currently affecting the coast, resulting in a mix of cloudy and sunny intervals with temperatures ranging between twenty-seven and thirty-two degrees.

Year's first red rainstorm

The sudden arrival of summer heat stands in stark contrast to the severe weather experienced earlier in the week. 

In an official weather blog, the observatory recalled the dramatic events of late Wednesday and early Thursday when the year's first Red Rainstorm Warning Signal was triggered. 

The unstable weather began on Wednesday night under the influence of strong southerly winds and upper-air disturbances, which sparked intense convective activity, heavy downpours, and squally thunderstorms across the Pearl River Estuary.

The observatory initially issued a Yellow Rainstorm Warning at nine o'clock on Wednesday night. 

While the heaviest downpours were initially localized, they quickly concentrated over the northern parts of the New Territories, dumping more than one hundred millimeters of rain and causing localized flooding.

Science of forecasting

As the rain bands expanded across the territory, the Geotechnical Engineering Office and the observatory jointly issued a landslide special advisory due to the high volume of accumulated rainfall and the subsequent risk of soil instability. 

At forty minutes past two on Thursday morning, the Observatory upgraded the alert to a Red Rainstorm Warning as widespread areas recorded over fifty millimeters of rain within a short period. 

The deluge finally began to ease after five o'clock in the morning, prompting meteorologists to downgrade the warning to yellow before canceling all rainstorm alerts by mid-morning.

Explaining the nature of the storm, the observatory pointed out that the development and movement of heavy rain in Hong Kong are highly unpredictable and random. 

While broad rainstorm warnings are reserved for times when widespread heavy rain is expected to exceed specific hourly thresholds, localized alerts and special flooding announcements for the northern New Territories are strategically deployed to warn specific communities of imminent danger without unnecessarily alarming the entire city.

𝗗𝗼𝘄𝗻𝗹𝗼𝗮𝗱 𝗧𝗵𝗲 𝗦𝘁𝗮𝗻𝗱𝗮𝗿𝗱 𝗔𝗽𝗽 ↓