MANILA -- The weather bureau on Friday clarified that Typhoon Kammuri, at the moment, is less likely to become a super typhoon once it enters the Philippine area of responsibility (PAR).
The Philippine Atmospheric, Geophysical and Astronomical Services Administration's (PAGASA) weather division chief, Esperanza Cayanan, made the remarks following social media posts claiming that "Kammuri" would hit the country as a super typhoon.
Cayanan, however, noted that "Kammuri" was forecast to steadily intensify before making landfall over southern Luzon.
Esparanza explained that the United States' Joint Typhoon Warning Center (JTWC) "uses one minute as wind averaging period for the estimation of maximum sustained winds near the center (MSW). PAGASA, on the other hand, uses a 10-minute averaging period."
Shorter wind averaging periods yield higher wind estimates than longer averaging periods. Thus, JTWC's MSW announcement is higher than the MSW provided by PAGASA.
She also clarified that meteorological centers use different thresholds in classifying tropical cyclones as a super typhoon.
Since 2015, PAGASA has been classifying a tropical cyclone as a super typhoon if the 10-minute MSW exceeds 185 kph.
JTWC's classification of a super typhoon, when converted from one- to 10-minute averaging period, has MSW exceeding 185 kph.
"That means that on a 10-minute averaging, JTWC has a lower threshold for classifying super typhoon than PAGASA," she said.
"Kammuri" was last tracked at 1,470 km. east of southern Luzon, slowly moving northwestward, according to PAGASA.
It has maximum sustained winds of 140 kph near the center and gustiness of up to 170 kph.
PAGASA forecast "Kammuri" to enter PAR between Saturday and Saturday. Once it reaches PAR, it will be named "Tisoy", the 20th Philippine tropical cyclone for this year.
Source: Philippines News Agency