| Popis: |
Convergence lines are formed during the winter monsoon season in the southern side of the Tokai on the southern Kanto region, Japan. The convergence lines with cumulus clouds (Cu) sometimes drive sudden changes in wind patterns and precipitation such as rain and snow. Therefore, the general conditions of cloud formation and precipitation with the convergence lines and their three-dimensional structure were examined by conducting case analyses when the conver-gence lines occurred. The convergence lines with the clouds stretching eastward formed in the upward current regions on the eastern side of a trough at the 500hPa level. A small cyclonic pressure system, that is a polar low, was generated by a trough with positive vorticity at 500hPa. Transport of a strong cold Siberian air mass and its subsequent inversion layer over the leeward mountainous regions of Central Japan led to the zonal cloud patterns off southeast of the Kanto region. |
