The maintenance processes of the large PW in the subtropical high over China were examined, based mainly on the GAME reanalysis data during June to July 1998. The schematic figure is shown in Fig. 7. In the subtropical high area to the south of the Meiyu/Baiu front, the larger amount of precipitable water was sustained over China with smaller temporal variation then over the East China Sea area. The large PW there was associated with the thick moist layer up to ～ 700 hPa level. In Period 2 (the first heavy rainfall event in Changjiang River Basin), extremely large PW and northward moisture transport was observed in the subtropical high area over China. In this case, the large northward flux with its maximum at ～ 900 hPa level would destabilize the stratification for moist shallow convection to result in the upward transport of moisture. On the other hand, although PW over the East China Sea area was rather small, PW in the subtropical high area over China was not so small. In this case, relatively large sensible heat, together with latent heat, was supplied from the ground there. The sensible heat flux seems to enable the moisture to be transported upward, at least, to upper than ～ 850 hPa level there, although the upward transport due to shallow cumulus clouds would not be so effective. The results in the present study imply that the subtropical high area over the continental part of China is under the favorable condition for maintenance of the huge moisture content without great fluctuations. This is because at least one of the above mentioned processes could be realized even when the synoptic situations change considerably.
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