Diagnostic Analysis on a Regional Rainstorm Weather in North-central Henan Province

[Objective] The research aimed to analyze a regional rainstorm weather process in north-central Henan Province. [Method] Based on the conventional meteorological observation data and the rainfall data of Henan Meteorological Station, the diagnostic analysis of atmospheric thermodynamics and dynamics on a rainstorm weather process in north-central Henan Province on July 19, 2010 was carried out. The characteristics of physical quantity field and the evolution of weather situation in north-central Henan Province when the rainstorm happened were studied. [Result] Western Pacific subtropical high strengthened to extend westward. The dynamic uplifting of low vortex at the middle and low layers, the strong water vapor transportation of southwest low-level jet caused the regional rainstorm weather process in north-central Henan Province. The diagnostic results of physical quantity showed that the deep, thick wet layer and the sustained water vapor convergence provided the abundant water vapor for rainstorm generation. The positive vorticity advection center developed and spread from northwest to southeast, which was favorable for the development of vertical movement. The structure maintenance of positive vorticity at the middle and low layers, negative vorticity at the middle and high levels provided the power condition for the regional rainstorm generation. The pumping effect of convergence at the middle and low layers, divergence at the high layer was favorable for the strengthening of vertical ascending motion at the low layer. The uplifting effect of dew point front at the middle and low layers triggered the release of unstable energy. The confrontation of warm and cold air was one of the important reasons for the regional rainstorm. TBB characteristic analysis showed that TBB was from -60 to -50 ℃ in north-central Henan Province in the whole strong precipitation time, and the moving speed was equivalent to that of southwest vortex. The low-value belt of TBB corresponded with the rainstorm occurrence zone in Henan, and the minimum-value center of TBB was basically consistent with the strongest center of precipitation. [Conclusion] The research provided the scientific basis for the short-term forecast of rainstorm.

Irregular Information of the Rainstorm in a Continuous Rainy Weather

[Objective] The research aimed to analyze irregular information of the local rainstorm process (during 5-6 September,2009) in autumn continuous rainy weather in north Shaanxi. [Method] Based on V-3θ chart, routine observation data provided by Micaps system, satellite cloud chart and data at 100 automatic meteorological stations of Shaanxi, for rainstorm process in autumn continuous rainy weather in north Shaanxi during 4-10 September, 2009, by using structure analysis method, irregular information in local rainstorm weather was analyzed. [Result] In whole precipitation process, atmospheric structure in rainstorm zone presented obvious evolution process. Before precipitation, typical atmospheric structure information of the sudden convective weather appeared. Obvious ultra-low temperature structure appeared at 200 hPa, and consistent clockwise rotation flow was at vertical wind field. Meanwhile, water vapor was sufficient, and unstable energy existed at low layer. Structure characteristic of the convective strong precipitation appeared by advancing for 12h. As precipitation weakened, unstable energy was released, and ultra-low temperature disappeared. [Conclusion] The research provided some thoughts for the forecast of such weather process.

基于WRF模式的好溪流域致洪暴雨千米尺度预报研究

鉴于好溪流域内多山地和丘陵,梅汛期和台汛期常突发强暴雨,致使其千米尺度下的数值预报难度较大的问题,选取好溪流域2015~2020年的10场致洪暴雨事件,利用中尺度数值天气预报模式WRF和GFS预报数据进行6、30、54 h的回顾性预报,并测试了5种云微物理参数化方案的敏感性。结果表明,在千米尺度下,WRF模式模拟的降雨量偏小,对山区的预报效果优于河谷地区;Lin方案的整体预报效果最佳,而WSM3方案最差;选取的10场极端降水事件受到台风和西南低空急流等异常天气的影响,Lin方案和WSM5方案适用性较好;WRF模式对暴雨的预报效果优于大暴雨。研究结果对于提高山区小流域致洪降雨的模拟和预报精度具有借鉴意义。

2023年5月4—5日铜鼓大暴雨天气分析

为了做好铜鼓大暴雨天气的预警预报工作,文章使用江西省气象资料查询系统和铜鼓县国家基本气象站气象数据、MICAPS平台、江西雷达拼图平台和宜春SA雷达基数据反演PUP产品等资料,对2023-05-04—2023-05-05铜鼓县大暴雨过程进行分析。结果表明:铜鼓大暴雨过程中,铜鼓国家基本气象站降雨量为152.7 mm/12 h,赣西北和赣东北为两个暴雨区;铜鼓国家基本气象站地面气象要素中,2 min平均风速和分钟内最大瞬时风速均较小;在两次短时强降水出现前,2 min平均风速和分钟内最大瞬时风速都有一个峰值;气温、水汽压变化较小;本站气压在短时强降水发生前有个升压过程,在短时强降水结束后有个降压过程;短时强降水高峰期不是闪电频次最密集时段;铜鼓大暴雨的天气系统在100 hPa高度上有明显出流区、500 hPa低槽、850 hPa切变(低涡)和西南急流、地面西南倒槽,在倒槽中江西北部存在辐合线;铜鼓回波特征为絮状回波团和回波短带;45 dBZ强回波面积≥100 km~2,强盛时强回波面积为457 km~2和650 km~2;强降水回波45 dBZ回波顶高度在7 km~8 km,比低质心强降水的回波顶偏高1 km~2 km。研究结果为监测预警铜鼓飑线天气提供了分析依据。

江西大暴雨天气闪电分布与回波强度关系

大暴雨过程中的闪电分布与雷达回波强度关系密切,根据闪电强弱可间接判断雷达回波的强弱变化,为分析回波系统演变趋势提供线索。使用自动站数据、常规天气图、闪电数据和雷达拼图等资料,采用雷电知识、雷达气象学原理及分析方法,对江西2022年4次大暴雨过程的暴雨实况、天气系统、闪电分布、雷达回波特征等进行分析,总结闪电与回波关系。结果表明,江西2022年汛期出现4次较大范围的大暴雨天气过程,主要分布在赣中赣北等地。500 hPa低槽、850 hPa切变线、100 hPa分流区、中等强度CAPE、低空急流和超低空急流等天气系统是造成江西大暴雨天气主要因素。另外,当强回波区≥45 dBZ时,与闪电密集区以及强降水区有对应关系,密集强闪电往往会比强回波和强降水超前出现。研究结果为江西大暴雨过程中闪电分布与雷达监测预警预报提供了分析依据。

2021年8月8日垫江县一次大暴雨天气过程分析

本文利用常规气象观测资料、NCEP再分析资料等相关气象资料对2021年8月8日垫江县一次大暴雨天气过程进行分析。结果表明:此次垫江县大暴雨天气是在高空槽东移南下、台风“卢碧”、高低空急流、高空辐散的耦合及低空西南涡的共同作用下产生的,这些影响为本次垫江县大暴雨天气的发生提供了有利的大尺度环流背景形势。

江西大暴雨天气三种雷达回波特征分析

为了做好江西大暴雨天气的监测预警工作,基于MICAPS天气图、江西自动站和雷达拼图等数据,采用天气学、雷达气象学等原理与方法,对江西2022年4次大暴雨天气中的三种雷达回波形态进行分析,结果表明:江西大暴雨回波形态有短带回波、冷锋回波带和低涡回波团三种;短带回波当单体移动方向与回波带走向近似一致时,降水最强;冷锋回波带在东移过程中呈现顺时针转动,最后演变成东西走向;低涡回波团沿槽前西南急流朝东北方向移动,与切变线雨带合并后,回波团进一步发展壮大。研究结果旨在为江西大暴雨及短时强降水天气的短临预报提供分析依据。

1981-2020年北京市门头沟区部分灾害天气分析

文章中运用线性趋势分析方法和滑动平均法统计分析了1981-2020年北京市门头沟区的暴雨、高温、雷电、大风和低温灾害性天气事件的年际变化趋势,并对每种灾害天气的多年月际分布进行了统计,旨在了解门头沟地区灾害天气演变规律,以便做好气象灾害防御工作。分析结果显示门头沟区除高温日以每10年1.3天的线性趋势递增外,暴雨日、雷暴日、大风日和低温日均在逐渐递减;暴雨大多发生在7月与8月;高温日发生在每年的5月、6月、7月和8月;雷电最早于春季3月来临,最晚于冬季12月结束;冬季大风最为频发,冷空气过程全年均可能发生。

Simulation of a torrential rainstorm in Xinjiang and gravity wave analysis

We used a weather research and forecasting model to simulate a torrential rainstorm that occurred in Xinjiang, China during June 16–17, 2016. The model successfully simulated the rainfall area, precipitation intensity, and changes in precipitation. We identified a clear wave signal using the two-dimensional fast Fourier transform method; the waves propagated westwards, with wavelengths of 45–20 km, periods of 50–120 min, and phase velocities mainly concentrated in the-25 m/s to-10 m/s range. The results of wavelet cross-spectral analysis further confirmed that the waves were gravity waves, peaking at 11：00 UTC, June 17, 2016. The gravity wave signal was identified along 79.17–79.93°E, 81.35–81.45°E and 81.5–81.83°E. The gravity waves detected along 81.5–81.83°E corresponded well with precipitation that accumulated in 1 h, indicating that gravity waves could be considered a rainstorm precursor in future precipitation forecasts.

Comparative Analysis of Two Local Heavy Rainstorms in Northwestern Shandong

[Objective] The aim was to comparatively analyze two local heavy rainstroms in northwestern Shandong Province, China. [Method] Based on the observation data from automatic weather station, sounding data and NCEP reanalysis data, two local heavy rainstorms at night on July 18 and August 9 in 2010 in northwestern Shandong was comparatively analyzed from the aspects of circulation situation, influence system and physical field, and the internal structure and possible formation mechanism of local heavy rain in Shandong were discussed further. [Result] The two rainstorms occurred in the forepart of southwest air in front of 500 hPa trough, and there was stronger atmospheric baroclinicity in the front zone near 850 hPa. The two rainstorms were affected by southwest warm and humid airflow at low level and shear line at 850 hPa; rainstorm often appeared in intensive area behind θse high-energy tongue, and rainstorm area corresponded with the area with high vertical speed well. From the differences, during the first rainstorm, there was obvious southwest low level jet and shear line at 700 hPa, and the area with high precipitation was located in the south of warm shear line at 700 hPa; during the latter rainstorm, there was no obvious southwest low level jet and shear line, and the area with high precipitation was located in the region between two high pressures. [Conclusion] The study could provide valuable thinking for the forecast of this kind of rainstorm in the future.

Analysis of a Heavy Rainstorm in Jincheng in August of 2010

[Objective] A heavy rainstorm in Jincheng in August in 2010 was expounded. [Method] By dint of the conventional meteorological data, and automatic weather station data, and Doppler radar data, one severe torrential rainstorm was analyzed from the aspect of circulation background, physical quantity field, satellite cloud image, and radar echo, etc. [Result] The rainstorm was in the circulation field of low-west-east-obstruction, and was formed under the middle and low layer shear line and low air torrent situation. The low layer shear and convergence of wind favorable to the lift of unsteady air around Jincheng. The intrusion of cold air in the low layer of convective layer and above the ground trigered such convective weather. The torrent of the low air in the southwest sent abundant water vapor to the rainstorm area. The high temperature and the moisture accumulated much unsteady energy for the generation of rainstorm. The main precipitation system of this process was the singular of convective echo which was stimulated by the ground mesoscale shear line. Under the guidance of southwest airstream of the low and middle air, the convective echo singular formed train effect by moving towards Jincheng and formed large rainstorm. Doppler radar data suggested that the characteristics of the generation, development and movement of this mesoscale rainstorm system. The strong precipitation center was in the large value area of the gradient in the back of the TBB center. [Conclusion] The study provided references for the forecast and pre-warning of temporary rainstorm of such kind.

ANALYSIS OF RAINSTORMS ASSOCIATED WITH SIMILAR TRACK TROPICAL CYCLONES HAITANG (0505) AND BILIS (0604)

It is generally thought that the influence of comparable track typhoons is approximately similar, but in fact their wind and especially their rainstorm distribution are often very different. Therefore, a contrastive analysis of rainstorms by tropical cyclones (TCs) Haitang (0505) and Bilis (0604), which are of a similar track, is designed to help understand the mechanism of the TC rainstorm and to improve forecasting skills. The daily rainfall of TC Haitang (0505) and Bilis (0604) is diagnosed and compared. The result indicates that these two TCs have similar precipitation distribution before landfall but different precipitation characteristics after landfall. Using NCEP/GFS analysis data, the synoptic situation is analyzed; water vapor transportation is discussed regarding the calculated water vapor flux and divergence. The results show that the heavy rainfall in the Zhejiang and Fujian Provinces associated with Haitang (0505) and Bilis (0604) before landfall results from a peripheral easterly wind, a combination of the tropical cyclone and the terrain. After landfall and moving far inland of the storm, the precipitation of Haitang is caused by water vapor convergence carried by its own circulation; it is much weaker than that in the coastal area. One of the important contributing factors to heavy rainstorms in southeast Zhejiang is a southeast jet stream, which is maintained over the southeast coast. In contrast, the South China Sea monsoon circulation transports large amounts of water vapor into Bilis – when a water-vapor transport belt south of the tropical cyclone significantly strengthens – which strengthens the transport. Then, it causes water vapor flux to converge on the south side of Bilis and diverge on the north side. Precipitation is much stronger on the south side than that on the north side. After Bilis travels far inland, the cold air guided by a north trough travels into the TC and remarkably enhances precipitation. In summary, combining vertical wind shear with water vapor transportation is a good way to predict rainstorms associated with landing tropical cyclones.

2022年全球重大天气气候事件

2022年,全球平均温度比工业化前水平高出约1.15℃(±0.13℃),是第五暖年。全球海平面继续上升,且加速上升趋势明显。北极海冰面积低于常年值,南极海冰面积创下历史新低。巴基斯坦、韩国、印度、孟加拉国、澳大利亚东部、巴西和非洲中部和南部地区遭受暴雨洪涝;北非地区和东非大部分地区发生严重干旱;欧洲、中国、美国、日本、巴基斯坦和印度等地遭遇创纪录的高温热浪;北美和欧洲遭受寒流和暴风雪侵袭;强对流天气频繁袭击世界各地;全球共生成40个热带气旋,数量和强度均低于历史平均水平。成因分析表明,7月北半球副热带高压带异常强大以及欧洲上空持续的极强暖高压,西欧地区整个对流层盛行下沉气流,造成欧洲多地出现破纪录的高温热浪;7—8月西太平洋副热带高压异常强大且偏西,孟加拉湾地区东部的水汽输送路径折向印度北部和巴基斯坦,在南亚和东亚夏季风的共同作用下低层水汽辐合极为强盛,导致了极端降水事件的长时段维持和严重洪灾的发生。

2022年4月25日江西暴雨强对流过程分析

利用常规天气图、雨量、大风等气象观测资料、江西WebGIS雷达拼图等平台资料,对2022年4月25日江西中北部大范围的强对流天气过程进行了分析,结果如下:短时强降水、雷暴大风、强雷电、146站次的8级以上大风(极大风速达29.6 m/s)是此次强对流过程主要的天气实况;“上干下湿”、低层辐合线、高空低槽、高层辐散、强盛的低空西南急流、超低空西南急流、地面气旋是此次强对流天气过程的主要影响系统;45~55 dBz带状强回波主要造成短时强降水,强回波带的走向与回波单体的移动方向较为一致,回波强度达55 dBz,并持续,是导致50 mm/h以上的极端强降水的主要回波特征;在环境条件、地理条件优越时,45 dBz以上的带状强回波所经之处,容易导致雷暴大风,而组合STI移动信息对于带状强回波未来1 h的移动趋势有明显指示意义。

江西修河流域大暴雨短时强降水特征分析

文章简要介绍了降水资料来源和分析方法,统计了江西修河流域2013—2022年大暴雨过程并分析了天气形势特征,最后从典型天气形势、雷达回波特征方面分析了短时强降水特征,所得结论以期为研究流域大暴雨、减轻洪涝灾害提供参考与依据。

建筑外墙智能高压淋水机器人研究与应用

针对传统PVC布管淋水压力小、检测效果差的问题,研发了一种智能高压淋水机器人,用于模拟台风暴雨天气对外墙渗漏的影响。智能高压淋水机器人由智能高压淋水设备、智能柔性吊装设备、智能淋水在线操控平台、智能水泵组成,可通过智能提升、移动喷淋、远程控制、实时监测(压力、水量和时间等)等功能,实现高压、高效、智能化的淋水检测,真正解决建筑外墙渗漏的质量隐患。

柳河一场特大暴雨天气过程分析

利用形势场、物理量场及卫星云图雷达等资料,对2022年6月29—30日柳河特大暴雨天气过程进行分析,副高后部切变和高空横槽是此次强降水的大尺度天气系统,西南暖湿气流与槽后西北冷空气碰撞是产生强对流天气的不稳定层结的重要原因;海上高压阻挡与青藏高压东移使两者之间形成狭窄、跨度较大切变,对流系统反复生成发展,并沿着切变线方向经过同一地区上空,呈现“列车效应”;物理量场相对湿度、对流有效位能、KI指数对流性指示较好;云图与雷达图有利于对流云团的识别,较好地监测区域降水强度及降水路径;前期柳河县降水频繁,水汽充足,局地地形抬升触发增加了降水的强度。

2022年8月12-13日阿拉善盟暴雨过程分析

利用自动气象站资料和EC再分析资料等相关气象资料,分析了2022年8月12日至13日阿拉善盟一次暴雨天气过程。结果表明:此次阿拉善暴雨天气主要是受副高和中高纬的西风带环流小波动频繁等影响而引起的。西风带短波槽和副高西侧偏南暖湿气流于副高外围西北侧交汇,促使阿拉善盟发生暴雨天气。此次过程水汽主要来源为孟加拉湾地区和我国东海地区,由西南气流和偏东气流持续将洋面上的水汽向阿拉善盟一带输送,为此次暴雨过程提供了充足的水汽条件。低层辐合、高层辐散的配置形成的“抽吸”效应,推动了大气抬升运动的形成,为此次过程提供了较好的动力条件;暴雨天气发生过程中,阿拉善盟处于假相当位温(θ_(se))高能量区,强降水落区的K指数普遍达到36℃以上,这些为此次过程提供不稳定能量条件。此次暴雨过程中,气象部门精准预报、提早预警、主动服务,加强上下联动,递进式做好气象预报预警服务,为当地防汛指挥和防灾减灾提供了有力的技术支撑。

2019年7月底甘南州一次对流性暴雨天气过程分析

利用自动气象站观测资料和NCEP再分析资料对2019年7月底甘南州一次对流性暴雨天气过程进行分析。结果显示:(1)在此次暴雨天气发生之前,中纬度欧亚大陆大气环流形势为两槽一脊型。此次暴雨天气的主要影响系统包括500 hPa高空槽、副高、低空急流以及地面冷锋。(2)降水期间,700 hPa甘南州相对湿度均达到80%以上,低空大气的饱和程度较高,700 hPa及以上高空水汽辐合显著,水汽输送条件好,为对流性暴雨天气的发生发展带来了丰沛的水汽条件。(3)对流性暴雨天气前,甘南州高空大气中已积聚了大量不稳定能量;午后,甘南州温度大幅增加,产生了强降水天气,意味着此次暴雨天气具备有利的不稳定能量条件。

2020年6月中下旬绍兴市一次暴雨天气过程诊断分析

利用自动气象站资料及NCEP再分析资料等相关气象资料对2020年6月中下旬绍兴市一次暴雨天气过程进行诊断分析。结果表明:此次绍兴市暴雨天气的主要影响系统包括500 hPa高空槽、700 hPa、850 hPa切变及高低空急流;水汽条件主要源于黄海及南海;从动力条件来看,此次暴雨天气过程呈现中高层辐散、中低层正涡度辐合的动力结构,并且整个对流层均分布着垂直上升运动,为此次暴雨天气的发生提供了有利的动力条件。