Former observatory director Shun Chi-ming on Tuesday warned that Super Typhoon Ragasa is more intense than Mangkhut which wreaked havoc across Hong Kong in 2018.

The city's highest typhoon warning, the Hurricane Signal No 10, was in force for 10 hours as Mangkhut hit the city. This was the second longest duration for the signal since World War II.

Speaking on RTHK's Backchat programme, Shun noted that Mangkhut made partial landfall over the Philippines before heading to the SAR.

"Super Typhoon Mangkhut in 2018, which landed over Luzon before hitting Hong Kong, was weakened by some 30 percent in terms of the maximum intensity," Shun said.

"But in this case, Ragasa seems to cross the Luzon Strait and emerge basically the same, with very strong intensity now heading towards Hong Kong."

Shun called for regional and international collaboration to enhance storm track forecasting amid the emergence of artificial intelligence.

"With different weather models developed around the world, this has led to much better forecasting of the tracks of tropical cyclones in the past couple of years. This is very evident. But still, we have the challenge of correctly predicting the intensity of tropical cyclones. And that's the area we need more collaboration to pursue," he said.

Shun also warned that from now on, Hong Kong can expect to see typhoons later in the year.

"Late typhoons now seem to be a norm. For example, last year, we saw in November four typhoons at the same time in the Western Pacific. So this is going to be our norm. Don't be caught by surprise if we are going to be hit by typhoons in October or even November."