Singapore on Tuesday night ( Sep 17 ), strong winds and heavy rain tore down trees in various locations.  ,
The immediate storm , was good brought about by a Sumatra storm, authorities told CNA.
What is this climate occurrence, and when does it occur?
What is a Sumatra thunderstorm?  ,
A thunderstorm is simply a sudden collapse of powerful winds followed by heavy rains. It is simple but extreme, and it can kill down as quickly as it started.
A Sumatra storm has traits unique to this place: it is a series of thunderstorms that develop over Indonesia’s Sumatra area or the Strait of Malacca before moving eastward to change Singapore and, eventually, Peninsula Malaysia.
In a common case, a storm line or storm line , can bring about one to two hours of torrential rain.
Wind gusts may reach up to 80kmh.
Squalls have a much larger impact along their path than regular storms because of their straight structure. However, their short diameter prevents swift passage of heavy rain and strong winds.
Storm lines are spatial weather systems that can last hundreds of kilometers, but they generally only hundreds of kilometers wide, and they typically move quickly, according to Professor Matthias Roth from the geography department of the National University of Singapore ( NUS).
According to the statement,” Their emergence is related to the cooling of the heat on the high ground in northern Sumatra by radiation.”
When do storms appear?  ,
Sumatra squall occurs usually between April and November during the southwest monsoon and during the intermonsoon periods.
” It’s strongly associated with southwest wind” , , said Dr Wang Jingyu,  , an assistant professor of physical geography at the National Institute of Education ( NIE ).
The “linear-shaped heat systems that cross the Malacca Strait and the Malay Peninsula are forced to fly over the Bukit Barisan mountain selection” are produced by the southerly winds.
Dr Wang added that on normal, storms occur five to 10 times per month during these peak times.
According to a 2020 review by the Meteorological Service Singapore, the land experiences , 45 storms per year on average.
Storms typically occur in the pre-dawn time or early day.