Thunderstorm Rhythm And Its Early-warning In Liaoning Area

Violent weather such as heavy rainfall, hail and lightning always accompany with strong thunderstorm process. Short-time heavy rainfall can easily cause the disaster of flood and geological hazard. Hail has seriously threatened to agricultural/industrial production and personal safety, because its sudden happening and short life cycle. Lightning is a weather phenomenon happens in the atmosphere, which has transient high current, high voltage and strong electromagnetic radiation. Different departments such as electric power, aerospace, chemical industry, insurance industry, construction industry and tourism industry's demand of lightning monitoring and early warning becomes more and more strong, because its randomness and quick disaster forming. Thunderstrom process is analyzed based on kinds of current observation data, corresponding references could be provided on lighting's prediction and early warning if the activity rhythm of thunderstorm can be known. Thunderstorm's accurate prediction can prevent disasters and reduce loss, so it is important to monitor and give early warning for the society.First, based on the conventional surface observational data of 59 stations in Liaoning from 1978 to 2007, temporal and spatial variation of thunderstorm day was analyzed in order to find the thunderstorm distribution of study area. The results indicated that, it presents a decreasing trend from east, west mountain area to central area, where is hill, plain and coast.Second, lightning position finder data from January 1,2007 to December 31,2010, were analyzed. The results show that ground lighting month is a single peak, which accords with the thunderstorm month distribution in Liaoning. The frequency of ground lighting is a descending trend, increases slowly at the beginning, and then decreases quickly, which is consistent with the thunderstorm activity rhythm of Liaoning area. However, the maximum of the data are not same, the reason was analyzed, and lightning strike disaster situation from 2007 to 2010 was calibrated, which shows that distribution of disaster is consistent with the thunder lighting distribution.According to the disaster situation of the disaster situation decision query system and file query system of Shenyang regional climate center, which have the description of rainstorm, hail and short-time thunderstorm with strong wind, the severe thunderstorm weather process form 2004 to 2010 of the doppler radar data comparing with the lightning position finder were analyzed, in order to find early-warning function of the 2 data, then screen the thunderstorm early-warning indexes of Liaoning area. Echo intensity>40dBz,0℃layer<4500m,8000m<-20℃layer< 8500m. are the forecast indexes of short-time heavy rainfall; Echo intensity> 40dBz, vertical liquid water>35kg/m2,0℃< layer<3000m,4500m<-20℃layer< 5500m are the forecast indexes of hail. Variation of the max echo top height and the total frequency of lighting have a better correspondence.Taking the thunderstorm weather occurred on July 8,2007, August 8,2008 and June 7,2008 as the examples, early warning indexes of thunderstorm weather were calibrated, which show better results.