Statistical Analysis And Windy Weather Forecast Methods In Dalian

The wind is one of the disastrous weather have a serious impact on Dalian area, but in the past for a long period of time, research on Dalian area wind is relatively less, although in recent years on the Bohai sea and the Yellow Sea and the Bohai Straits have some basic research, its climate characteristic of coastal gale research focus in the Yellow Sea, Bohai, the Bohai Strait statistics and typical case analysis of storm surge, the overall lack of systematic, comprehensive, deep and specific research methods. Dalian area wind comprehensive system research, not only can effectively improve the accuracy rate of forecast and early warning and timely, reduce bring gale disasters on the economic and social losses, at the same time has revealed the wind characteristics of Liaodong peninsula area of scientific significance.In this paper, using the data from1969January to2008December a total of40years in Dalian area8national meteorological observation stations at the height of10m wind field ground observation data (day time refers to the day before Beijing time20to20hours on the same day), station observation data from automatic weather stations, upper air sounding data, satellite data and NCEP grid point data and other meteorological data. Statistical analysis of climate change law of Dalian area wind, clear temporal and spatial variation characteristics of gale weather in Dalian area system and weather situation, focusing on the influence of level8or above of the instantaneous wind. Referring to the existing research results and windy weather type business forecast work experience, study the temporal and spatial variation characteristics of gale weather Dalian area, summarized the effects of strong winds typical types of Dalian area.Based on the statistical Dalian area wind data over the past40years, from the time, space and climate change trend of Dalian area wind change characteristics of statistical analysis, research shows that:Dalian area annual strong wind days have obvious interannual change feature, and gradually less seasonal variation trend; Dalian winds is also obviously, the largest wind in spring, summer, autumn and winter, gale frequency relatively less:from the geographical distribution in southern area of Dalian annual gale days was significantly higher than that in the northern region, the eastern region is slightly higher than the western region.Census Dalian and the surrounding coastal gale weather historical examples, and according to the weather theory to analyze the main impact of Dalian and the surrounding coastal wind system and weather situation, and carried on the research and classified by statistical analysis, the influence of situation similar merge, contrast and so on the windy weather, sum up4main types:influence (1) High pressure type gale;(2) A cold gale;(3) cyclonic gale;(4) the typhoon gale. At the same time, a cold wind and pressure type wind up, cyclonic winds times, typhoon gale frequency minimum.Sample winter cold front gale and cyclonic Gale Process typical, in2008November7-9and2008December two day weather Winter Gale4-5diagnostic analysis. The results showed that:(1) the atmospheric circulation directly influences the formation and maintenance of the wind. North the strong cold air moving to Southeast in guiding the upper northwest flow in the high latitude, altitude southwest warm wet air current moving northward transport, increased pressure gradient of air, increasing the baroclinicity, has a promoting effect on the momentum from the high-altitude passes down the pressure gradient and the enhancement of the ground.(2) the upper trough in front of the positive vorticity advection of temperature advection and low layer flow is conducive to the development of the surface low pressure enhancement, is the basic condition for the formation of low pressure gale. The vertical structure of low level divergence, mid-level convergence caused by momentum exchange, resulting in low pressure gale wind speed increase.(3) continue to supplement and upper troposphere cold air, are favorable to the formation of cold air gale and continuous.(4) strong cold advection intensified the vertical disturbing Huang Bohai warm ocean on low layer convergence, vertical circulation rose formed the ground motion is beneficial to increase the kinetic energy of the wind speed, the kinetic energy produced an increase of input area.On the basis of the situation on the ground in Dalian area field,850hPa low level circulation and500hPa upper situation, carries on the statistics of Dalian and the surrounding coastal winds cause the main effect system of the intensity and location selection, gale forecast factor, the3D conceptual model establishing Dalian area wind, a wind forecast index, and the gale forecast index test report and inspection.The climate statistics and case analysis of Dalian area gale, reveals the spatial and temporal distribution characteristics of Dalian area wind, summarized the main influencing system establishment of windy weather, high pressure type, cold front, cyclone gale3D conceptual model, and obtains the corresponding wind forecast index and test report, concluded that:when the request the24hour maximum wind, strong wind forecast forecast accuracy high pressure type28.6%, type57.1%cold front, cyclone type57.1%; very strong wind forecast accuracy rate of71.4%quasi high pressure type, cold type was71.4%, cyclone type71.4%.48hour winds forecast maximum wind forecast accuracy high pressure type57.1%, type42.9%cold front, cyclone type71.4%; extreme wind forecast accuracy high pressure type71.4%, type42.9%cold front, cyclone type85.7%. The24hour maximum wind forecast testing accuracy cold front, cyclone type is greater than the pressure type;24hours of extreme wind equally accurate;48hours maximum wind and extreme winds forecast accuracy is the highest pressure type cyclone, the second lowest, cold front. Comprehensive consideration,24hours of cold front and cyclonic gale forecast can use the corresponding model and index,48hours of high pressure type and the cyclonic gale forecast can use the corresponding model and index.