The South China Sea is looking interesting.  Satellite image and a couple of charts on my web-page

John McB

Johnny Chan (City University of Hong Kong)

Dear John:

Since you initiated the discussion on the South China Sea monsoon, I might
as well put in my observations.

Recall the discussion earlier about the twin cyclones first in the Arabian
Sea and South Indian Ocean, and then in the Bay of Bengal (BoB) and South
Indian Ocean (see Mark Lander's sat pix on 9 May, as attached).

At that  time, I discussed this with colleagues and suggested the onset of the South
China Sea (SCS) summer monsoon (SCSSM) would be less than a week later,
based on the average time lag of about 1 week between the appearance of a
vortex over BoB and the onset of the SCSSM.  Indeed, westerlies abruptly
occurred over much of the SCS from 13 May (see attached time-latitude
x-section), and hence the onset.

Time-Longitude section of 850 zonal wind averaged from 110-120E, from 1 April (top) to 28 April (bottom).

Convection was generally maintained over the SCS from then on until a
couple of days ago when easterlies began to strengthen in the northern
part of the SCS (see same x-section) due to a weak northeasterly surge
from the north.  This coupled with the westerlies to spin up the convection
that gave birth to TD06W (although only JTWC labelled it as such).
The entire monsoon trough is likely to move northward and affect South
China and the Taiwan Strait.  This might actually hamper the effort to
retrieve the bodies and black box of the downed China Airlines plane.

Johnny Chan