Abstract:

 Two typhoons called Muifa (1109) and Bolaven (1215) formed over the Yellow Sea area both moved northward and affected Liaodong Peninsula. There were errors in the forecast of precipitation and wind intensity for these two typhoon processes. Based on the conventional meteorological data, observational data from intensive automatic weather stations and the NCEP reanalysis data, the above two typhoons were compared and analyzed. The results show that low trough at mid-high latitude (from 110°E to 120°E) of 500 hPa, the Okhotsk blocking high, the change of Subtropical High intensity and shape, and the northern cold air all significantly affect the northward track and intensity of the typhoons. The northern cold air was important to precipitation caused by northward typhoon, and spiral rain band around the typhoon leads to precipitation. The Japan Sea High ridge stretching to northeastern China influences significantly gale. The duration of typhoon impact is closely relative to involvement of cold air after landfall.

Key words:  Northwardly typhoon, Liaodong Peninsula, Cold air