KOTA KINABALU (THE STAR/ASIA NEWS NETWORK) - Threatening cloud formations in south-western Beaufort have created a stir among the people as pictures and videos went viral on social media.

To allay the concern of people in Beaufort and the surrounding areas, meteorologist Lim Ze Hui has stepped in to explain that the cloud formations were squall lines that came about as a result of several thunderstorms banding together in a line.

A squall line usually forms between a cold front and a warm front, the acting Meteorological Department director explained, saying that there is no need for any panic or worry over the weather condition.

Since early Monday (June 28), heavy rains and thunderstorms have hit Beaufort and the south-western area, northern Kudat district, Kota Kinabalu and Labuan before tailing off by noon.

According to Mr Lim, the weather condition is due to the current south-west monsoon and has nothing to do with a tropical storm over the South China Sea off the northern Philippines.

"There is nothing to fear," he assured the public.

In a statement, Science, Technology and Innovation Minister Datuk Seri Madius Tangau said the extraordinary formation was harmless.

"This happened before in Kota Kinabalu in 2012, Sungai Petani in 2014 and in Kota Baru last year," he said, adding that the phenomenon happened along with rolling clouds.

"The length of the squall line can go on for several kilometres with a relatively long life span when compared to the usual thunderstorm," he added.

A squall line can result in strong winds of over 32kmh and protracted heavy rain.

Due to this, the Meteorological Department has issued a warning on possible thunderstorms on the west coast of Sabah and Labuan and bad weather conditions for aviation.

Beaufort OCPD Deputy Supt Azmir Abd Razak said the downpour at about 8am lasted less than two hours and did not result in flash floods or unwanted incidents.