Abstract: Based on hourly precipitation data at 1587 automatic weather stations in Liaoning province from May to October during 2010-2018,we identified short-term rainstorm and heavy rainstorm events according to the standards of orange and red rainstorm warning signals issued by China Meteorological Administration.The spatial distribution and multi-scale temporal variations of the short-term rainstorm and heavy rainstorm were analyzed to obtain high-incidence areas and periods after synoptic analysis.The results showed that high-incidence areas of short-term heavy rainstorm events are distributed in the southeastern coastland of Liaoning province.The mutual effects of weather systems such as cold vortex in Northeast China,cyclone moving to the north,and subtropical high in the western Pacific probably result in the frequent occurrence of heavy and persistent rainstorm events over wide areas.The ten-day variations of day numbers of the short-term rainstorm and heavy rainstorm exhibit a "convex" shape,with a single peak between early May to early October.The occurrence frequency of heavy rainstorm significantly increase after early July and decrease sharply after late August.The diurnal variations of rainstorm and heavy rainstorm events exhibit the "two peaks and one valley" pattern.Rainstorm events mostly occur at night,which is probably due to the strengthening of southwestern jets.The highest occurrence frequency of short-term rainstorm occurs from 00:00 to 08:00 Local Standard Time (LST),especially in areas of Fuxin-Chaoyang,Fushun-Panjin-Huludao,and the southeastern Liaoning province.The high-incidence areas of short-term heavy rainstorm between 00:00 and 08:00 LST include the western,eastern and southeastern parts of Liaoning province.

Key words: Short-term rainstorm, Short-term heavy rainstorm, Warning signal