Abstract:The spatial and temporal characteristics of drought in the north of China from Feb to July, 2000, the features compared with those in China history and aboard, the reasons of drought in atmosphere, ocean, weather and climate features as well as global climate change, the influences on the developments of industry and agriculture, human activities, water resource and ecosystem were analyzed.The prediction of rainfall anomaly and its service in the passed spring and summer are reviewed, and the precipitation predictions in the coming autumn, winter and spring were looking ahead In the end, a suggestion was given that while working out the emergency scheme of drought, protecting the ecosphere environment and water resource, the operational development and study works of meteorology and climate must be enhanced, such as the weather modification, the early warning system as well as the mechanism research of drought.

Abstract:Some problems determining prediction indicator set for hailfall with stepwise decreasing FAR method,such as the determining procedure,the searching key,the identification and the number of the prediction indicator,were discussed.

Abstract:The composite analysis of some major physical quantities in a few hours before 12 heavy rains occurring in the upper reaches of the Changjiang River reveales mesoscale features of flow, energy and moisture fields.Analytic results may be applied into prediction of heavy rain in the region.

Abstract:The weather circulation pattern of the summer tight precipitation period and the main heavy rain course in 1998 were analyzed with the NCAR/NCEP and daily precipitation data from 94 surface stations in Songhuajiang and Nenjiang area.The continuous rainfall can be contributed to the following weather patterns:(1)the steady blocking pattern in the middle and high latitude of Asia,(2) controlled by cold vortex long term,(3)advancing north ward of the subtropical high over the west Pacific and its suitable position,(4)the strong monsoon in midsummer.

Abstract:The NCAR/NCEP re-analysis data and the daily precipitation data in July—August,1998 from 94 surface stations in the Songhuajiang and Nenjiang area were used to analyze vapor transport,which causes a severe flood of 1998.The analysis considers that the meridional transport of abundant vapor is the key.The water source comes from the low latitude south of the subtropical high over the west Pacific and the Indian Ocean.The strength of south jet,position of the subtropical high over the west Pacific and so on, are closely related to summer monsoon, affecting vapor transport.

Abstract:The meteorological and hydrological data in the Songhuajiang and Nenjiang area were used to discuss the effect of precipitation on the change of the water level.The conclusion is that there is a close relationship between the water level in floodwater season and the precipitation over the Songhuajiang and Nenjiang area.The severe flood in the summer of 1998 was caused by more precipitation over the Nenjiang river.The daily change of water level is closely related to the upstream water level and the precipitation over the near region.

Abstract:Surface observation of hourly precipitation, infrared pictures of stationary satellite and TBB were used to discuss the feature of two cloud types of meso-scale rain cluster and TBB over the Nenjiang and Songhuajiang area in 1998.The conclusion shows the features of the meso scale rain cluster generation, development,movement, and extinction.

Abstract:A detail method of recognizing hail cloud was introduced by stepwise decreasing FAR.The synoptic pattern,convective parameter and radar echo parameter were used for the factors to produce the indicator set of hail cloud recognition.

Abstract:The evaporation capacity in the summer (May to Sep.) from 1986 to 1997 and ice surface evaporation in the winter of 1997 (Oct.to next Apr.),measured by small-sized evaporation gauge,were compared with the measurement by E₆₀₁ at Changchun National Standard climatic station.The conversion coefficient of two Rinds evaporation data was obtained by correlation analysis and contrast.The climate estimated values of E₆₀₁ evaporation for years in succession were obtained.

Abstract:Through the test,contrast and analysis among the three numerical prediction products of T106 HLAFS and Japanese model used in present work on the effect of Yantai rainfall prediction,it is found that the numerical prediction products have some directive functions in the rainstorm and rainfall prediction,and Japanese model is better than HLAFS.Yet,HLAFS is better than T106 on the effect of the rainstorm and general rainfall prediction.The accurate rate of rainfall prediction of the three prediction products to the low pressure and upside down trough is commonly higher,and the accuracy of rainfall is 75.9% when the three prediction products all predict that there will be rainfall.

Abstract:The diagnosis analyses of the heavy rain process over the east part of the Qingzang Plateau on 9—10 September 1999 was made, and the cloud band pattern and physics fields of the heavy rain process was summarized.

Abstract:The main substance, function and features of the new generation weather forecast system in Henan province were described.The system developed by Henan Meteorological Observatory consists of two versions, or SGI working station and computer.