Weather TALK [forecasts, etc]

[Jun aka Pekto]

so they missed the effect of that high pressure in china, which caused pepeng to back out a bit ... and now that high pressure is probably gone, with the pressure at the east maybe higher, they are now again forcasting the usual route, westbound?

from the looks of it, it looks like pepeng have the tendency to be attracted by melong, now in japan, so baka mag-northbound sya ... ah ewan, kaya nga ang tawag sa mga yan bagyo eh, pabago-bago isip!

I have my doubts it's simply a matter of Pepeng being attracted towards Melor.

What keeps a tropical system tracking westward is usually a strong (semi-permanent) High over the Pacific. The center of the High is way out there. But it has "ridges" or arms of high pressure extending hundreds to thousands of miles out. Highs in the Northern Hemisphere have a clockwise motion. So, if a ridge extends westward from a High east of the Philippines, a typhoon has to get around that ridge. Hence it moves westward. Once it rounds the corner (where the ridge ends), it then starts moving northeastward because of the Earth's rotation. The northwest quadrant of a High moves towards the northeast or if we're talking about where the wind is coming from, southwesterly. Same premise for the southwest monsoon.