Abstract:Interactive Forecast Preparation System (IFPS) has been one of the highest priority projects of the National Weather Service (NWS) for years. It is also an important component of Advanced Weather Interactive Processing System. The NWS has been developing and testing techniques that support interactive forecast preparation for more than a decade. With interactive operation, IFPS could help forecasters to predict and deliver products effectively. The basic structure of IFPS is introduced and some interactive technical details used in IFPS are discussed. Not only does it show some operational applications of the NWS, but it also gives some useful reference relating to the development of the Chinese New Generation Weather Forecast Process.

Abstract:Based on weather facts and synoptic cause of formation, a strong dust devil weather case occurred on 18th to 19th April, 1998 is analyzed and diagnosed, and then numerical simulation with nonhydrostatic MM5 model for this case is made. The result shows that cold air from the western Siberian moves rapidly eastward and forms strong frontal zone over the western Xinjiang, which corresponding surface cold front moves to such special underlying surface as desert, gobi in Xinjiang, Inner Mongolia, Gansu and Ningxia provinces where were heated, and as a result, gale, strong dust devil weather would form. The MM5 model can successfully simulate the formation and development of this surface severe gale and upper air front zone.

Abstract:Using vapor convergence and condensation method, the vapor convergence rate, condensation rate and precipitation efficiencies of the main synoptic systems in spring and autumn during 1997-1999 in Shandong Province are calculated. The spatial distribution and the difference of the above mentioned characteristics concerning the south cyclone and northwest cold front are analyzed. The results can be used for choosing the seeding area and designing flight course in the artificial precipitation enhancement operation.

Abstract:The ETA model of the Chengdu Regional Meteorological Center has its function of forecasting the heavy rainfall occurring in the Northwestern Sichuan Basin on 18 Sept. of 2001. The model can reveal the movement and stability of the rainfall area ,and the tendency of the alleviation in rainfall intensity except a little weakness in the intensity and difference in the rainfall area. The numerical experiment shows that during the early stage of the process, southwest and southeast air flow in the middle and lower troposphere are very important to the rainfall while this is not true for the cold air from north.

Abstract:Based on the T106 objective analysis data obtained from 17 to 21 September of 2001,the physical conditions and possible mechanism of Sichuan ″9.18″ torrential rain are analyzed. The results reveal that northward low level south east jet would cause favorable thermodynamic, moisture and dynamic conditions for the heavy rainfall in the northwestern Sichuan. The strong upward vertical movement, resulted from the convergence ascending of low level south east jet exit region and the local topographic forcing, stimulated strong convective clouds. The heavy rain was amplified to a great extent by local topographic forcing, and the convergence of low level wet air.

Abstract:The heavy rain process causing mud rock flow calamity in the northwestern Sichuan Basin on 18-20, sept. 2001 is analyzed. The results are obtained as follows: (1) Heavy rain causing mud rock flow is connection with early rain day, intensity of heavy rain, geology, landforms. It is suitable that the forecasting area are divided by geology landforms for the heavy rain causing mud rock flow. (2)The weather influence systems at 500hPa are difference in the early and late period of the heavy rain. (3) The heavy rain is presented under the condition of the strong positive vorticity, convergence, vapor flux convergence in middle and lower troposphere and stronger divergence at upper troposphere. (4) Q-vector convergence band has indicative significance for the heavy rain. Specially, Q-vector analysis is more beneficial when the weather influence system is not obvious.

Abstract:Using the radar echo data, a heavy rain event occurred in the northwestern Sichuan basin from 18 to 20 September of 2001 is investigated. The results show that the strong precipitation area is coincided with the echo variation with the intensity of 45dBz. In fall season, when the strong echoes with 45-55dBz presented in the floccose echo region, the radar warning observation should be conducted. Furthermore, the middle intensity echoes in the flooding region should also be tracked and observed, and the service to the users should be made.

Abstract:During 19-21 September of 2001, a rare heavy rain event was suddenly appeared and accompanied with powerful thunderstorm over Mianyang region. Under the condition of insufficient energy is not enough and stable atmospheric stratification after lasting a month with rainy weather. Its forming reasons using meteorology, NWF products, satellite image, and energy condition etc. are analyzed. It's considered that existence and stretch northwards of higher energy tongue with the type Ω in the low layer is a major reason for the heavy rainfall appeared suddenly. It is main energy of the suddenly arising rare torrential rain that releasing of latent heat energy for warm and wet flowing atmosphere climbing along could front face. The feedback speed up the low pressure grow, form the CISK(second unstable condition)mechanism. The article raise a point of view for movement′s energy accumulating, and attempt to explain the reason forming the suddenly arising torrential rain under condition of lower temperature and stable atmosphere.

Abstract:WMO suggests that period of normals expressing the anomaly of an element variable can be changed from the old period of 1961-1990 to a new period 1971-2000.Because of the different normals,the anomaly of an element,such as the temperature,precipitation,SST and geopotential height,will be changed.The winter temperature anomaly will be 0.5℃ below in the northern part of China.The summer rainfall anomaly will be more in the Yellow River valley,the North China and Northeast China,and will be less in the Northwest China and the south of Yangtze River.It is based on the different climate state in the two periods of 1960s and 1990s.

Abstract:The statistical analysis of climatological data concerning the strong northeast monsoon caused by cold air during the decade from 1988 to 1997 along the coast of Guangdong province reveals that the monthly change of the northeast monsoon is clear, and its interannual change is reducing. It is closer related with the surface predictors than that with the 850hPa ones. In addition, the location of the center of surface cold high, which would change with the different month and the forecast period, has high centralization.

Abstract:Based on WSR-88D radar data, the radar echo′s characteristics of the torrential rain in Shanghai on the night of August 5th 2001 are analyzed to find out its precipitation mechanism and characteristic.It is found that a south wind velocity convergence on the side of subtropical high,the echo′s consolidation in the spiral rain band,convergence caused by wind′s perpendicular shear and high precipitation rate of tropical system are the precipitation mechanism and characteristic of the rain event.Some key points are presented about forecasting this kind of heavy rain events:heavy precipitation echo′s appearance and development are always related with local strong convergence in wind field,local convergence′s appearance and evolution can be found from the continuous change of Doppler radar wind data,thus,the forecast of heavy precipitation′s probability can be made.

Abstract:Based on the analysis of the meteorological data of Beijing area during the period of 1961-2000,the characteristics of sandy and dust weather in Beijing are discussed. Also, the possible way of preventing and controlling of dust devil is discussed.

Abstract:The instability of wind in speed and direction could lead to vibration in the structure and cause its damage. Because the meteorological data to be take in the longer period but free-vibration period of the construction is order of magnitude in second, the present data to describe instability of wind does not meet the demand of the construction motive analyzing. The observation of simultaneous change of wind speed and direction by seconds at seaside, mountain and outskirts of a city shows that instability of wind is less in the seaside and is more in the outskirts and wind observed is some instability in different direction of wind in the mountain site. It indicates the unsteadiness of natural wind in the wind velocity and direction is mainly related with the landforms and relief. Therefore, the wind dynamical analysis is necessary for constructions working in the disadvantageous landform conditions.

Abstract:By statistical analysis of the data of outpatients day by day from a hospital and meteorological data in Lanzhou form 1996 to 1998, 2000, a daily grade forecast equation is built in the seasons for eight diseases, the pathological repository is also built. Based on the relation of meteorology and disease, Lanzhou medical meteorological forecasting system was built, which includes automatically collection and data processing, MICAPS system, figure display of the evolvement of the meteorological factors, edit manuscript, automatically printing system, etc. This system has already been running since October of 2001. The result shows that the forecast result has high accuracy, the system runs well and it has high robotization.