Research on classification forecast method of severe convective weather in Heilongjiang province based on CMA-MESO

Using the European center reanalysis data (ERA5), China Meteorological Administration mesoscale numerical prediction model (CMA-MESO) products and automatic station data, the convection parameters such as dynamic conditions, unstable stratification, water vapor conditions, and characteristic layer height were calculated, and the statistical characteristics of the quantile value of convection parameters for thunderstorm gale and short-term heavy rainfall, as well as the deviation characteristics of the climate value were counted.The results show that short-term heavy rainfall is more likely to occur in the middle and lower atmosphere which is nearly saturated in the humid and hot environment with high water vapor content.The uplift of the middle and lower layers triggers precipitation and enhances precipitation efficiency.Water vapor condition is the key to short-term heavy rainfall.Thunderstorm gale is easy to happen in the environment with large temperature drop rate, and especially for the conditions with dryness in the middle layer, wetness in the low layer, large vertical wind shear and large Cape.By using the relative deviation fuzzy matrix evaluation method, the classification forecast of two types of severe convective weather in Heilongjiang province is tested.The results show that the method can effectively predict the area and time in which severe convection is most likely to happen and has a good forecast effect and the reasonable rate of missing and falsity.The forecast BIAS is 0.7 for short-term heavy rainfall and 1.04 for thunderstorm gale.