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1.
Russell L. Elsberry Mary S. Jordan Frederic Vitart 《Asia-Pacific Journal of Atmospheric Sciences》2010,46(2):135-153
The objective of this study is to provide evidence of predictability on intraseasonal time scales (10–30 days) for western North Pacific tropical cyclone formation and subsequent tracks using the 51-member ECMWF 32-day forecasts made once a week from 5 June through 25 December 2008. Ensemble storms are defined by grouping ensemble member vortices whose positions are within a specified separation distance that is equal to 180 n mi at the initial forecast time t and increases linearly to 420 n mi at Day 14 and then is constant. The 12-h track segments are calculated with a Weighted-Mean Vector Motion technique in which the weighting factor is inversely proportional to the distance from the endpoint of the previous 12-h motion vector. Seventy-six percent of the ensemble storms had five or fewer member vortices. On average, the ensemble storms begin 2.5 days before the first entry of the Joint Typhoon Warning Center (JTWC) best-track file, tend to translate too slowly in the deep tropics, and persist for longer periods over land. A strict objective matching technique with the JTWC storms is combined with a second subjective procedure that is then applied to identify nearby ensemble storms that would indicate a greater likelihood of a tropical cyclone developing in that region with that track orientation. The ensemble storms identified in the ECMWF 32-day forecasts provided guidance on intraseasonal timescales of the formations and tracks of the three strongest typhoons and two other typhoons, but not for two early season typhoons and the late season Dolphin. Four strong tropical storms were predicted consistently over Week-1 through Week-4, as was one weak tropical storm. Two other weak tropical storms, three tropical cyclones that developed from precursor baroclinic systems, and three other tropical depressions were not predicted on intraseasonal timescales. At least for the strongest tropical cyclones during the peak season, the ECMWF 32-day ensemble provides guidance of formation and tracks on 10–30 day timescales. 相似文献
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A review of progress over the past 50 years in observing and forecasting of tropical cyclones is presented. Tremendous progress has been made in track forecasting in the past 20 years with the improvement in numerical model guidance and the use of consensus forecasting, and this has contributed to a number of warning centers now issuing five-day track forecasts that are as accurate as three-day forecasts of a decade ago. Techniques are now available to specify the track forecast uncertainty for assessing the risk of a tropical cyclone. With the advent of five-day forecasts, a focus on improved understanding of formation has led to two field experiments. A recent advance has been in extended-range (5–30 days) forecasts of tropical cyclone events (formations and tracks) in the western North Pacific from the ECMWF 32-day ensemble predictions. This advance is a contribution to a goal of seamless forecasting from one day to a season for tropical cyclones. Little progress has been made in intensity forecasting, although the Hurricane Forecast Improvement Project in the United States and recent field experiments may offer some future advances. Some advances in forecasting tropical cyclone impacts such as storm surge, surface waves, and precipitation have been achieved. Future opportunities for continued advances are possible such that improved warnings can lead to reductions in losses of lives and minimizing damages from tropical cyclones. 相似文献
3.
给出了一个嵌套于欧洲中期天气预报中心全球谱模式中的套网格模式,用于预报热带气旋路径趋势,提出了一种以欧洲中期天气预报中心提供的时距为24小时的预报场为基础的“接力预报”方法;设计了五种不同的“接力预报”方案;并对8507号和8509号两个热带气旋就各种不同预报方案进行了数值预报试验。结果表明,本模式对热带气旋路径趋势具有较强的预报能力,对疑难路径也具有一定的预报能力,为开展热带气旋的路径趋势预报提供了一个新的途径。文中还对影响热带气旋路径趋势的一些主要因子结合各预报结果进行了分析,为模式尽早投入业务提供了一定的依据。 相似文献
4.
Lili LEI Yangjinxi GE Zhe-Min TAN Yi ZHANG Kekuan CHU Xin QIU Qifeng QIAN 《大气科学进展》2022,39(11):1816-1832
An ensemble Kalman filter(EnKF) combined with the Advanced Research Weather Research and Forecasting model(WRF) is cycled and evaluated for western North Pacific(WNP) typhoons of year 2016. Conventional in situ data, radiance observations, and tropical cyclone(TC) minimum sea level pressure(SLP) are assimilated every 6 h using an 80-member ensemble. For all TC categories, the 6-h ensemble priors from the WRF/EnKF system have an appropriate amount of variance for TC tracks but have insufficient v... 相似文献
5.
Tropical cyclone track and intensity prediction: The generation and assimilation of high-density, satellite-derived data 总被引:1,自引:0,他引:1
J. F. Le Marshall L. M. Leslie R. F. Abbey Jr. L. Qi 《Meteorology and Atmospheric Physics》2002,80(1-4):43-57
Summary The impact of recent scientific and technological advances in tropical cyclone track, intensity and structure modeling is
discussed. Since the early 1990s, developments have occurred in remote sensing, data assimilation procedures, numerical models
and high performance computing. In particular, there is now quasi-continuous high spatial and temporal resolution data coverage
over the previously data-sparse oceans where tropical cyclones spend most of their life cycles. There has been a rapid development
of data assimilation methodologies capable of using these data to initialize high-resolution prediction models. Model developments
have reached a stage of maturity where the representation of many of the physical processes necessary for improved tropical
cyclone track and intensity prediction are now included. Finally, available computer power has reached the teraflop range.
Most operational centers have high performance computers capable of tropical cyclone modeling at resolutions necessary for
skillful track and intensity simulations.
This article focuses on combining all of the above developments in a tropical cyclone data analysis and prediction system.
The system has produced statistically significant reductions in the mean forecast error statistics for tropical cyclone track
predictions and resulted in far more realistic simulations of tropical cyclone intensity and structure. A large number of
tropical cyclones have been modeled, with emphasis on those classified as being “difficult” storms to predict accurately.
These difficult storms are most responsible for rapidly growing forecast errors. Our results are illustrated by case studies
of such tropical cyclones.
Received October 9, 2001 Revised December 28, 2001 相似文献
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7.
Matthew Ranson Carolyn Kousky Matthias Ruth Lesley Jantarasami Allison Crimmins Lisa Tarquinio 《Climatic change》2014,127(2):227-241
This paper provides the first quantitative synthesis of the rapidly growing literature on future tropical and extratropical cyclone damages under climate change. We estimate a probability distribution for the predicted impact of changes in global surface air temperatures on future storm damages, using an ensemble of 478 estimates of the temperature-damage relationship from nineteen studies. Our analysis produces three main empirical results. First, we find strong but not conclusive support for the hypothesis that climate change will cause damages from tropical cyclones and wind storms to increase, with most models predicting higher future storm damages due to climate change. Second, there is substantial variation in projected changes in losses across regions. Potential changes in damages are greatest in the North Atlantic basin, where the multi-model average predicts that a 2.5 °C increase in global surface air temperature would cause hurricane damages to increase by 63 %. The ensemble predictions for Western North Pacific tropical cyclones and European wind storms (extratropical cyclones) are +28 % and +23 %, respectively. Finally, our analysis shows that existing models of storm damages under climate change generate a wide range of predictions, ranging from moderate decreases to very large increases in losses. 相似文献
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Summary From 1994 to 2003, fifty-five tropical cyclones entered the Canadian Hurricane Centre (CHC) Response Zone, or about 42% of
all named Atlantic tropical cyclones in this ten-year period, and 2003 was the fourth consecutive year for a tropical cyclone
to make landfall in Canada. The CHC forecasts all tropical cyclones that enter the CHC Response Zone and assumes the lead
in forecasting once the cyclone enters its area of forecast responsibility. This study acknowledges the challenges of forecasting
such tropical cyclones at extratropical latitudes. If a tropical cyclone has been declared extratropical, global models may
no longer use vortex bogussing to carry the cyclone, and even if it is modeled, large model errors often result. The purpose
of this study is to develop a new version of the Florida State University (FSU) hurricane superensemble with greater skill
in tracking tropical cyclones, especially at extratropical latitudes. This has been achieved from the development of the synthetic
superensemble, which is similar to the operational version of the multi-model superensemble that is used at FSU. The synthetic
superensemble differs in that is has a larger set of member models consisting of regular member models, synthetic versions
of these models, and the operational superensemble and its synthetic version. This synthetic superensemble is being used here
to forecast hurricane tracks from the 2001, 2002, and 2003 hurricane seasons. The track forecasts from this method have generally
less error than those of the member models, the operational superensemble, and the ensemble mean. This study shows that the
synthetic superensemble performs consistently well and would be an asset to operational hurricane track forecasting. 相似文献
11.
Sanjeev Kumar Singh C. M. Kishtawal Neeru Jaiswal Randhir Singh P. K. Pal 《Meteorology and Atmospheric Physics》2012,117(3-4):103-120
In the present study, a new approach is discussed to find out the residual steering flow from the high-resolution global Numerical Weather Prediction (NWP) model-forecasted wind fields, which have been used in the Lagrangian advection model to determine the track of tropical cyclones formed in the Indian Ocean. The Lagrangian advection model is newly developed model and conceptually closer to the dynamical models, which utilizes environmental steering flow and the effect due to earth’s rotation (the beta-effect) to determine the motion of cyclone. In this approach, the effect of environmental flow on the cyclone track is examined by removing the existing cyclone vortex from the steering flow which is determined by potential vorticity approach. A new approach based on vortex pattern matching has been used to identify the cyclone vortex and to remove it from the steering flow. The tracks of five tropical cyclones (viz., Nargis, Khai_Muk, Nisha, Aila and Phyan) which were formed in the North Indian basin during the period 2008–2009 have been generated by the Lagrangian advection model using the proposed scheme. The position errors were computed with respect to the Joint Typhoon Warning Center (JTWC) best track analysis positions and compared with that of without-vortex-removal scheme. The results show that the mean track errors for five cyclones are reduced by 6–35?% for 12–72?h forecast in case of vortex-removal scheme as compared to the without-vortex-removal scheme. 相似文献
12.
2013年欧洲中心台风集合预报的检验 总被引:1,自引:0,他引:1
广州中心气象台利用中国气象局下发的欧洲中心台风集合预报数据,制作了台风集合预报产品,供业务参考应用。利用欧洲中心台风集合预报数据,对2013年1307—1331号热带气旋的集合预报路径和强度进行检验,通过对比集合平均、模式高分辨率确定性预报和预报员主观预报,发现路径集合平均在24~120 h预报误差最小;在有限的预报样本数中,从热带风暴到台风级别的热带气旋,各预报时效路径集合平均的误差随强度增强而减小;强引导气流背景下的热带气旋预报误差小于弱引导气流的误差。对比强度集合平均和模式高分辨率确定性预报,发现各时效集合平均的误差比确定性预报大,随着预报时效的延长误差没有明显增大或减小的趋势,而且强度集合平均预报,在中心最低气压、中心最大风速、热带气旋等级都表现出明显的系统性偏弱特征;对不同级别的热带气旋强度预报,集合平均的误差随强度增强而增大,即强度集合预报对强度较弱的热带气旋有更高的准确率;对比受强、弱引导气流影响的两类热带气旋,集合平均对受弱引导气流影响的一类预报误差更小。 相似文献
13.
以MM5模式为试验模式,分别用增长模繁殖法(BGM)和模式物理过程扰(MPP)形成12个集合成员,对2005年登陆我国的8个热带气旋进行了52次路径集合预报试验,以寻找适合西北太平洋热带气旋路径的集合预报方法。结果表明:BGM方法的集合预报结果总体上好于控制试验结果,其中对强度较弱的热带气旋的集合预报效果更好。MPP方法的集合预报结果总体上不如控制试验结果,但对初始时刻强度达到台风的热带气旋的集合预报效果较好,集合预报相对于控制试验的改进效果明显。基于BGM方法和MPP方法集合预报的不同特点,将两种方法相结合形成扰动成员,这一综合方法的集合预报效果好于单一方法的集合预报效果。BGM方法和MPP方法的系统发散度总体上都偏小。 相似文献
14.
The paper shows the statistical analysis of cyclone tracks that have influence on the western Antarcticregion.Based on the conditions of cyclone movement and its impact upon the weather,cyclone tracks areclassified into three categories,i.e.,the track moving towards the northern tip of the Antarctic Peninsula,southern track,and northern track.Moreover,in this paper,the frequency distributions of cyclone tracks,the major tracks with higherfrequencies,the original region of Antarctic cyclones and the seasonal features of Antarctic cyclones have beenanalyzed.The results show that there are higher cyclogeneses in summer,whereas relatively fewer cycloge-neses in winter,and cyclone numbers in transitional seasons are close to the climatological average.Theanalysis also shows that the moving velocity of Antarctic cyclone is about the same in winter and summer.It obviously speed up during the transitional season. 相似文献
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The Dynamical-Statistical-Analog Ensemble Forecast model for landfalling tropical cyclones (TCs) precipitation (DSAEF_LTP) utilises an operational numerical weather prediction (NWP) model for the forecast track, while the precipitation forecast is obtained by finding analog cyclones, and making a precipitation forecast from an ensemble of the analogs. This study addresses TCs that occurred from 2004 to 2019 in Southeast China with 47 TCs as training samples and 18 TCs for independent forecast experiments. Experiments use four model versions. The control experiment DSAEF_LTP_1 includes three factors including TC track, landfall season, and TC intensity to determine analogs. Versions DSAEF_LTP_2, DSAEF_LTP_3, and DSAEF_LTP_4 respectively integrate improved similarity region, improved ensemble method, and improvements in both parameters. Results show that the DSAEF_LTP model with new values of similarity region and ensemble method (DSAEF_LTP_4) performs best in the simulation experiment, while the DSAEF_LTP model with new values only of ensemble method (DSAEF_LTP_3) performs best in the forecast experiment. The reason for the difference between simulation (training sample) and forecast (independent sample) may be that the proportion of TC with typical tracks (southeast to northwest movement or landfall over Southeast China) has changed significantly between samples. Forecast performance is compared with that of three global dynamical models (ECMWF, GRAPES, and GFS) and a regional dynamical model (SMS-WARMS). The DSAEF_LTP model performs better than the dynamical models and tends to produce more false alarms in accumulated forecast precipitation above 250 mm and 100 mm. Compared with TCs without heavy precipitation or typical tracks, TCs with these characteristics are better forecasted by the DSAEF_LTP model. 相似文献
17.
R. L. Elsberry 《Meteorology and Atmospheric Physics》1995,56(1-2):81-99
Summary Considerable advancements have recently been made in understanding tropical cyclone motion. Based on these new understandings, the requirements for accurate tropical cyclone motion prediction with dynamical models can be specified. Four issues related to dynamical track prediction are the initial specifications of the environmental wind field, the symmetric vortex and the asymmetric vortex structure, as well as the adequacy of the models to predict the time evolution of each of these three components of the total wind field. Recently developed barotropic and limited-region or global baroclinic models are examined in terms of these issues. The capability of the Hurricane Research Division barotropic model to provide skillful track forecasts to 48 h retrospectively substantiates that tropical cyclones motion is governed by barotropic dynamics to first order. Limited-region baroclinic models are demonstrated to have many of the numerical characteristics, physical process representations, and initial condition specifications that will be required to properly predict tropical cyclone tracks. In particular, the semioperational Geophysical Fluid Dynamics Laboratory model most closely addresses all of the above issues, and has demonstrated potential for markedly improved tracks for a small sample of cases. Finally, the inclusion of some aspects of tropical cyclone structure in the initial conditions of global baroclinic models has improved their track predictions. Thus, the outlook is for a significant improvement in dynamical track predictions.With 6 Figures 相似文献
18.
浙江省热带气旋倒槽暴雨气候特征研究 总被引:2,自引:1,他引:2
基于近40年热带气旋(Tropical Cyclone,简称TC)日降水和最佳路径等观测资料,采用数理统计、天气学分析等方法对浙江省TC倒槽暴雨分布特征及其与TC的相互关系进行研究。(1)浙江省年均会发生1.8次TC倒槽暴雨,占TC暴雨总数约4成,是浙江省台风暴雨中的一种重要形式。每年8—9月是TC倒槽暴雨高发期,暴雨主要发生在宁波南部至温州一带沿海地区,暴雨中心多位于台州和温州沿海。(2)引发浙江省TC倒槽暴雨的热带气旋多在粤东至浙南登陆之后北上转向或西北行,登陆当天最易发生暴雨且雨强最强。暴雨发生时,福建中部沿海经海峡至台湾东北部一带是TC高频活动区。(3)距TC中心2.5~5.0纬距之间和TC东北偏北象限是倒槽暴雨中心的高频落区;较强暴雨发生在TC强度为热带低压时,且强中心易位于TC东北偏东象限,极端强降水发生主要与热带低压和副高等相互作用形成的偏东暖湿急流、TC倒槽强辐合和TC东北偏东象限中尺度深对流系统频繁活动有关。 相似文献
19.
本文利用ERA5 1979-2019年逐月大气再分析资料计算南北印度洋热带气旋生成指数,并和IBTrACS观测数据进行比较,探讨用热带气旋生成指数研究南北印度洋热带气旋变化特征的适用性.研究发现热带气旋生成指数能较好地刻画南北印度洋热带气旋的空间分布特征、北印度洋热带气旋个数月变化的双峰结构,以及南印度洋比北印度洋热带气旋发生概率高等特征.最新的IBTrACS v4.0观测资料显示,40年来北印度洋热带气旋每年总生成个数平均每10年增加1.3个,频数的增加主要来源于热带低压和热带风暴,而南印度洋热带气旋每年总生成个数每10年减少2.8个.热带气旋生成指数能很好地描述北印度洋热带气旋生成个数的上升趋势,但对南印度洋热带气旋生成个数趋势的刻画与观测不一致,可能原因需要进一步深入研究. 相似文献
20.
采用美国联合台风警报中心(JTWC)提供的北印度洋1977-2008年热带气旋资料、NOAA提供的1982-2008年高分辨率合成资料和NCEP提供的1982-2008年全球再分析资料,对北印度洋上167个热带气旋个例进行了统计分析,结果表明:1)北印度洋热带气旋通常发生在阿拉伯海东部和孟加拉湾中部,阿拉伯海上活动的热... 相似文献