Model results reveal a larger precipitation frequency over
urban area, mainly contributed by the light rain events (< 10
mm d−1). Consistent with satellite observation, around 10-20%
more precipitation occurs in urban area than rural area in the
afternoon induced by more unstable urban PBL, which induces
a strong vertical atmospheric mixing and moisture transport to
the upper layer. A significant enhancement of precipitation is
found in the downwind region of urban area in our simulations
in the afternoon.