As of today, the Joint Typhoon Warning Centre estimated Halong's intensity at 257km/h. But there are plenty of reasons to believe that may be conservative, and that Halong is still intensifying.
"The latest automated values from [the Advanced Dvorak Technique] have it up to 165 knots!" wrote Philip Klotzbach, a hurricane researcher at Colorado State University. That 165 knots equals 305 km/h. Hurricane Dorian, which ravaged the Bahamas in September, had maximum winds of 297 km/h.
Klotzbach referred to the Advanced Dvorak Technique, a means to assign storm intensity remotely using just satellite observations. The Joint Typhoon Warning Centre does not dispatch aircraft into typhoons.
This could put Halong into the top dozen or so tropical cyclones ever observed by weather satellite, based on values churned out by the Dvorak method. The so-called "satellite era" dates back to 1979.
The terrifying shots from above show extremely cold, high cloud tops raging about an ominous, warm eye.
Klotzbach did note that water temperatures in the region being traversed by Halong are slightly above normal, but not by a wide margin. "It's just normally stinking hot in the western North Pacific!" he wrote.
It's been a busy year for typhoons in the West Pacific. Barely a month ago, Hagibis leaped from a tropical storm to a Category five-equivalent Super Typhoon in just 18 hours, intensifying at one of the fastest rates ever recorded.
Hagibis socked Japan thereafter as a Category one or two equivalent, but unloaded torrents of rainfall. More than 1m fell on Hakone in Kanagowa Prefecture in 24 hours, the widespread flooding wreaking havoc across Japan.
Back in February, another Super Typhoon reached Category five status. The storm, named Wutip, sideswiped Guam, bringing 10.7cm of rain to Antonio B. Won Pat International Airport on February 24. Farther to the south, flash flooding struck Inarajan, which recorded a whopping 43cm.
Three Category fives in the west Pacific may sound bad, but it can be far worse; nine of them had spun up by this point in the year back in 1997.
Halong is the seventh Super Typhoon in the west Pacific this year, as well as the 13th typhoon. There have been 29 named storms.
The storm's rapid rate of intensification is consistent with what climate scientists expect in a warming world. There is evidence that rapidly intensifying storms are already becoming more common in the North Atlantic Ocean, for example.
A 2017 study that examined modelled Atlantic storms showed an uptick in the number of storms that would rapidly intensify just before landfall in a warmer world. Another study, published in 2018, found that with continued global warming, more tropical cyclones are likely to undergo rapid intensification than in the past.
Halong is forecast to remain entirely out to sea and begin to weaken some in the next three days or so. In the meantime, though, waves near the storm's centre will top 9 to 12m.
