vu Thanh Hang, Kieu Thi Xin

According to Krishnamurti, improvements of physical parameterizations will
mainly affect simulations for the tropics [10]. The study of William A. Gallus Jr. showed
that the higher the model resolution and more detailed convective parameterizations,
the better the skill in quantitative precipitation forecast (QPF) in general [16]. The
quality of precipitation forecast is so sensitive to convective parameterization scheme
(CPS) used in the model as well as model resolution. The fact shows that for high
resolution regional model like H14-31 CPS based on low-level moisture convergence as
Tiedtke did not give good heavy rainfall forecast in Vietnam. In this paper we used the
scheme of Betts-Miller-Janjic (BMJ) based on the convective adjustment toward tropical
observationally structures in reality instead of Tiedtke in H14-31. Statistical verification
results and verification using CRA method of H14-31 of two CPSs for seperated cases
and for three rain seasons (2003-2005) shows that heavy rainfall forecast of H14-31/BMJ
is better than one of H14-31/TK for Vietnam-South China Sea. CRA verification also
shows that it is possible to say that heavy rainfall forecast skill of H14-31/BMJ in tropics
is nearly similar to the skill of LAPS of Australia.