Based on the numerical prediction interpretation techniques and forecast experiences，the short － term objective forecast system
of meteorological elements for Northwest China is established． With the aid of meteorological data of real － time observation，the
verification and assessments of objective forecast from the system － output for air temperature and precipitation in winter of 2006 have
been performed． The results show: ( 1) The forecast accuracy of maximum and minimum temperature is much higher than that of precipitation
with the accurate rates of 70% and 34%，respectively． ( 2) The factors affecting the forecast accuracies of temperature and
precipitation are the static stability of atmosphere and relative humidity． ( 3) If the system established on month scale，the forecast accuracy
of temperature is expected to have a 10% improvement．

The main functions of Surfer software，ActiveX automation technique and the interface of VB application and Surfer are introduced in this paper．It is also introduced how to combine the strong ability of development using VB software and the strong mapping in  Surfer based on the interface．and the key program to Ca／Ty out the interface technique and a case of application automatic mapping are presented．

The content，structure，functions，characteristics and key implementing technologies of the Guiding Weather Forecast System in Northwest China are introduced in detail，which is a three levels network architecture based on Active Server Pages（ASP）technology and the Browser / Server（B/ S）. It proves in the practical application that this system is a perfect meteorological information management system for its integrating and sharing information among each department of meteorological bureaus expediently.

 A regional heavy rain process o<(urged in Cansu province on 19 August in 2004 was analyzed from the weather and Climatic
background Circulation Characteristics as well as the(hange of different physical quantities and the evolution of the Cloud Cluster  at
the same time it was simulated by MM5.  Results show that the favorable weather(ondition and the(onvergenc;e of the low一level wind
are the main reasons of this heavy rain the moving of the heavy rain zone lagged the strong(onvec;tive(loud band on FY一2C hourly
satellite images. The simulated result indicates that MMS is available for forecasting the intensity and location of the rainfall partic;ular-
1y for 12一48 hours rainfall forec;asting} it has some signific;anc;e for forecasting strong rainfall events

The previous atmospheric Circulation adjustment and development,strong frost and freeze injury Climate background, weather CharacteristiC，west wind inDex、hanged T213 objective forecast of the rare event OCurged on May 3一5 in 2004 in Cansu provence were analyzed in the paper and it will have some certain directive signific;anc;e for frost predic;tion} disaster prevention and fin fiber in the future.

Based on the "h213 materials of National Meteorological Center and an actual need of the operation and scrv}cc operational system of Lanzhou limited area mesoscale numerical prediction model based on MM5 has   thebeen set up.  A lark    the number of forecasting products arc acquired from the system everyday, which have already become important benchmark for forecasting operation and service，and play more and more important role in elaborate prediction，extreme weather event predic t lon(for example, the torrential rain) and the meteorological geological calamity prediction，ctc.

Based on the historical material of T106 model and observed data of stations, we obtain the predictor after handling the da-
ta, and build the MOS prediction equations about the temperature, wind, cloud and precipitation of 80 stations in Gansu Province.
After the operational application, we get the better prediction results, and supply an objective tool for weatherman.

According to statistical analysis of the seasonal change of the SouthAsia high，the date of the first regional precipitation over
10 mm（the first soaking rain）in spring and the date of changing to more rain period in early summer in Gansu province，the paper reveals the correlativity primarily among the South Asia high during its seasonal change and setting up above Qinghai-
Tibet Plateau，the first soaking rain in spring and changing to more rain period in early summer in Gansu especially in the east region of the River.
Analyse results indicate that there is remarkable relation between the South Asia High visiting the Middle-Southern Peninsulas during its seasonal change and the first soaking rain in spring in Gansu，and between the South Asia high setting up above Qinghai-Tibet plateau and changing to more rain period in early summer in Gansu as well.So it’s important to know the seasonal change of the South Asia high and the date of its visiting the Plateau for us to predict the appearance of the first soaking rain and the date of changing to more rain peiod accurately.

Based on the geological calamity relevant materials of the past 40 years in Gansu province，the current situations，geographical distribution characteristic of geological calamity and its happening characteristic in Gansu were introduced. It also demonstratedthat the meteorological factors such as hardrain etc，are the main factors leading geological calamity in Gansu.The prediction method of geological calamity was given out and the preliminary prediction mode was set up as well，and its effect was examined by using geological calamity which was actually happening in 2003 in Gansu province，found that the rate of accuracy reaches more than 73%，it proved that the prediction mode has certain prediction ability.