In my last update yesterday to my post on erstwhile super typhoon Pepeng, this is what I wrote:
FUJIWHARA EFFECT ORFUJIWARA INTERACTIONIn the meantime, you might want to take a look at this Pagasa update on typhoon Pepeng courtesy of GMANews.tv. The 24 Oras video clip was posted at the GMA News website at 8:19pm.It shows Dr. Nathaniel Cruz of Pagasa discussing with Mel Tiangco the possibility of typhoon Pepeng remaining more or less stationary for the next two or three days. He attributed this phenomenon to the presence of a high pressure area in China and the approach of the typhoon Melor farther out in the Pacific. These two factors combine to force typhoon Pepeng to stay more or less where it is right now. Dr. Cruz explained that after typhoon Melor enters the Philippine area of responsibility within the next day or two, it will then turn northward and only after that will typhoon Pepeng be able to move away from its present position. The phenomenon is known as the Fujiwhara effect or Fujiwara interaction named after the Japanese meteorologist who first described it in a 1921 paper about the motion of vortices in water.Before Pepeng eventually moves away from its present position, it is expected to swing back and pass over Northern Luzon anew, according to Dr. Cruz.
Typhoons Pepeng and Quedan (international codename Melor) have actually managed be within the Philippine area of responsibility at the same time when Quedan entered the Philippine area of responsibility this afternoon.
Pepeng was located at 4 this afternoon at around 220 kms. North northwest of Laoag, Ilocos Norte with maximum sustained winds 105 kph and gustiness of 135 kph. It is expected to remain stationary for about two days. Quedan at 4pm was situated at 1,130 kms. East southeast of Basco, Batanes with maximum sustained winds of 205 kph and gustiness of 250 kph. It is expected to move West northwest at 26 kph.
More on this story in this News on Q report featuring a discussion of the two typhoons among Dr. Nathaniel Cruz of Pagasa, Lala Roque and Ivan Mayrina.