用动力相似方法预报8月份暴雨

利用1989～1998高空资料和东营市降水资料,采用修改的动力相似方法研制出8月份暴雨预报系统,经检验和试用,无漏报,历史拟合率为65.9%,试报准确率为33.3%.     

用动力相似方法预报8月份暴雨

利用1989-1998高空资料和东营市降水资料，采用修改的动力相似方法研制出8月份暴雨预报系统经检验和试用，无漏报，历史拟合率为65.9%，试报准确率为33.3%。     

铜川市暴雨动力相似预报方法

利用高空实况资料客观分析,计算出多层、多时次的诸物理量格点资料,采用动力相似方法,找出铜川市有暴雨日与无暴雨日的前期、开始、过程中的物理量气候差别,建立暴雨动力相似预报方法,业务化时用实况资料与T2 1 3数值产品共同作预报,效果良好     

利用动力相似法作梧州地区台风暴雨短期预报

首先计算在台风暴雨出现前24小时，25个探空站相应的24个物理量场，利用相关分析，筛选出能较好地反映暴雨天气系统的物理量场，并用动力相似法作出24小时台风暴雨落区预报。最后用动力因子作出逐步回归预报方程来比较效果。     

HLAFS产品暴雨动力过程相似预报方法研究

阐述了“HLAFS产品暴雨动力过程相似预报方法”制作的过程、应用及其对暴雨的预报性能，指出：本方法对暴雨预报的检验效果比较满意，能够达到人工预报暴雨的水平，对暴雨的漏报率很小，具有较好的推广前景。     

宁夏暴雨动力相似过滤预报系统

通过对北京ＨＬＡＦＳ暴雨模式产品中诸多物理量场与历史个例进行动力过程相检验,在较全面地掌握预报对象的三维空间物理结构和动力过程前提下,通过渗入有明确天气学意义,并对宁夏暴雨有实际预报能力的综合指标和模型,在天气系统自动识别技术的支持下,应用螺旋度修正方案,建立自动、客观化的暴雨落区预报系统。     

鹤壁市暴雨相似预报系统

利用欧洲中心3层数值预报产品，综合运用相似系数和距离系数，研制了既反映环流形势相似又反映强度值相似的鹤壁市暴雨24h预报系统。     

综合相似预报法在短期暴雨预报中的应用

该文选取１９６１－１９９８年４－１１月造成陕西暴雨天气的５８６个个例，用专家预报暴雨经验与多元相似相结合，把每个个例总一组暴雨指标，同时又做为和以相似的历史样本，在有限区域内对陕西暴雨天气进行短期预报，１９８９年７－８月作预报９次，其次确率达７８％。     

试用相似离度方法作暴雨中期预报

试用相似离度方法作暴雨中期预报白瑞芳苗玉芝梁明珠（山西省气象台０３０００６）１引言目前数值预报已有了相当的预报水平，在对数值预报产品作统计动力释用的过程中，相似预报方法仍被广泛使用。常用作相似比较的标准有相似系数、海明距离、欧氏距离等。国内已有人对这...     

相似方法在夏季降水预报中的应用

以短期降水为研究对象,利用Ｔ１０６资料提供的７００ｈＰａ高度场和８５０ｈＰａθｓｅ场格点资料,计算欧氏距离找相似的方法,实现了２４、４８ｈ２１个市（县）夏季降水预报的自动化。经检验达到一定的精度,可成为日常预报的参考工具。     

1994年6月广东省特大洪涝期间气象要素的小波分析

通过对１９９４年６月广东洪涝期间省内南雄与电白两站逐时地面降水、气压和温度的小波分析,清楚地将影响两站的不同尺度的扰动显示出来,利用小波方差图可帮助确定该段时间的主要天气系统,利用小波逆变换可对原序列进行多种形式的重构。     

1994年6月广东省特大洪涝期间气象要素的小波分析

通过对１９９４年６月广东洪涝期间省内南雄与电白两部逐时地面降水、气压和温度和小波分析,清楚地将影响两站的不同尺度的扰动显示出来,利用小波方差图可帮助确定该段时间的主要天气系统,利用小波逆变换可对原序称进行多种形式的重构。     

低纬度地区局地暴雨的神经网络预报方法研究

以南宁市所辖8个站暴雨集中的6-8月逐日降水量作为预报对象,采用人工神经网络方法进行了新的数值预报产品释用预报方法研究.通过运用动力相似法,结合日本降水预报模式对未来暴雨发生的可能性进行判别,然后通过对欧洲中期数值预报中心预报场进行滑动分区车氏展开计算,求出与降水量序列相关较好的预报因子,并对这些因子进行自然正交分解,有效浓缩数值预报产品因子,建立了南宁市逐日暴雨的神经网络释用预报模型.利用该预报模型,对2006年6-8月的逐日暴雨预报试验结果表明,该预报模型对南宁市的暴雨强降水具有很好的预报能力.     

IMPROVEMENT OF REGIONAL PREDICTION OF SEA FOG ON GUANGDONG COASTLAND USING THE FACTOR OF TEMPERATURE DIFFERENCE IN THE NEAR-SURFACE LAYER

The relationship between the factor of temperature difference of the near-surface layer(T_(1000 hPa)-T_(2m))and sea fog is analyzed using the NCEP reanalysis with a horizontal resolution of l°xl°(2000 to 2011) and the station observations(2010 to 2011).The element is treated as the prediction variable factor in the GRAPES model and used to improve the regional prediction of sea fog on Guangdong coastland.(1) The relationship between this factor and the occurrence of sea fog is explicit:When the sea fog happens,the value of this factor is always large in some specific periods,and the negative value of this factor decreases significantly or turns positive,suggesting the enhancement of warm and moist advection of air flow near the surface,which favors the development of sea fog.(2) The transportation of warm and moist advection over Guangdong coastland is featured by some stages and the jumping among these states.It also gets stronger over time.Meanwhile,the northward propagation of warm and moist advection is quite consistent with the northward advancing of sea fog from south to north along the coastland of China.(3) The GRAPES model can well simulate and realize the factor of near-surface temperature difference.Besides,the accuracy of regional prediction of marine fog,the relevant threat score and Heidke skill score are all improved when the factor is involved.     

COMPARISON STUDY ON THE INTRASEASONAL VARIATIONS IN CIRCULATIONS AND PRECIPITATION MODULATED BY THE TROPICAL CYCLOGENESIS OVER SOUTH CHINA SEA–WESTERN PACIFIC DURING GUANGDONG FLOODING PERIOD

Based on tropical cyclone datasets from Shanghai Typhoon Institute of China Meteorological Administration, the National Centers for Environmental Prediction (NCEP, USA) reanalysis data and the rainfall records from 743 stations in China, the impacts of cyclogenesis number over the South China Sea and the western Pacific are studied on the 30-60-day oscillations in the precipitation of Guangdong during the flooding period. The year with more-than-normal (less-than-normal) tropical cyclogenesis is defined as a ‘high year’ (‘low year’). In light of the irregular periodic oscillations, the method used to construct the composite life cycle is based on nine consecutive phases in each of the cycles. Phases 1, 3, 5, and 7 correspond to, respectively, the time when precipitation anomalies reach the minimum, a positive transition (negative-turning-to-positive) phase, the maximum, and a negative transition phase. The results showed that the precipitation of the 30-60-day oscillations is associated with the interaction between a well-organized eastward propagation system from the Arabian Sea/Bay of Bengal and a westward-propagating system (with cyclonic and anticyclonic anomalies in the northwest-southeast direction) from the South China Sea to western Pacific during the high years, whereas the precipitation is affected during a low year by the circulation over the South China Sea and western Pacific (with cyclonic and anticyclonic anomalies in the northeast-southwest direction). During the high year, the warm and wet air mass from the ocean to the west and south are transported to Guangdong by westerly anomalies and an enclosed latitudinal cell, which ascends in the Northern Hemisphere low latitudes and descends in the Southern Hemisphere low latitudes. During the low year, the warm and wet air mass from the ocean to the south is transported to Guangdong by southwesterly wind anomalies and local ascending movements. Because the kinetic energy, westerly, easterly shift, vertical velocity and vapor transportation averaged over (109–119° E, 10–20° N) is stronger in high years than those in low years, the precipitation of the 30-60-day oscillations in Guangdong is higher in high years than that in low years.