Lee Tsz-cheung, a senior scientific officer on the Observatory, stated the rainfall on Saturday was unusual and fell in an “extraordinarily uneven” means.
He attributed the various precipitation in several components of town to the low pace at which the rain clouds moved.
Leung Wing Mo, a former assistant director of the Observatory, stated it was uncommon to document greater than 200mm of rainfall in a day in Might.
He stated that though he was “not 100 per cent positive” whether or not Saturday’s rainfall was a direct results of local weather change, the prevalence of such an occasion was anticipated to be extra frequent because of world warming.
2. When has Hong Kong recorded more-than-usual rainfall in Might?
Official statistics present that Hong Kong was hit with 520mm of rain on Might 30, 1889, adopted by 324mm on Might 8, 1992. The town additionally recorded 273mm of rain on Might 24, 2017.
3. Why did the rainstorm come so abruptly?
Leung stated present meteorological applied sciences may solely predict whether or not the general climate sample was beneficial for heavy rainfall.
“The Observatory can predict which climate system could trigger heavy rain,” he stated. “However with present know-how, it’s unattainable to foretell when the rainstorm will come, how heavy it will likely be and the place it can happen.
“If yesterday’s forecast stated there could be heavy showers right now, it will solely be a normal abstract of right now’s scenario.”
Leung stated the Observatory’s rainstorm indicators already supplied the general public with real-time climate data.
“The Observatory issued an amber rainstorm warning earlier than it began to rain closely,” he famous. “And because the rain intensified, the warning stage was raised to pink. The issuance of such indicators has achieved the aim of nowcasting.”
The pink rainstorm warning was in impact from 8.55am to three.50pm earlier than being lowered to an amber sign.
4. What about the remainder of the nation?
Since mid-April, southern China has been affected by a trough of low strain, upper-altitude disturbances and divergences, leading to rainstorms which have lasted for days.
Statistics present that as of April 25, rainfall in lots of areas of Guangdong province broke native data for the month of April, with the cumulative rainfall within the metropolis of Shaoguan reaching 4 occasions regular ranges.
In Hong Kong, April was additionally wetter than regular, with the entire rainfall exceeding the typical worth by 68 per cent. The convective climate that affected Guangdong additionally triggered waterspouts in Clear Water Bay, hail in Yuen Lengthy and 110km/h gusts in Tai O.
The Observatory stated rising world temperatures elevated the quantity of water vapour within the environment and sped up the rain cycle, thus rising the possibility of heavy rainfall.
5. What must you do in preparation for the unstable climate?
The newest climate forecast confirmed that the rainfall would begin to subside on Sunday and provides solution to vivid and sizzling climate on Monday and Tuesday.
Nonetheless, an easterly airflow will attain the coast of southern China on Wednesday, bringing showers and robust winds alongside the coast.
The Observatory reminded the general public to concentrate to the most recent climate forecasts earlier than planning out of doors actions and going out.
Leung stated two-hour forecasts have been out there on the Observatory’s cellular app.