Analysis of characteristics and evaluation of forecast accuracy for Super Typhoon Doksuri(2023)

Super Typhoon Doksuri is a significant meteorological challenge for China this year due to its strong intensity and wide influence range,as well as significant and prolonged hazards.In this work,we studied Doksuri's main characteristics and assessed its forecast accuracy meticulously based on official forecasts,global models and regional models with lead times varying from 1 to 5 days.The results indicate that Typhoon Doksuri underwent rapid intensification and made landfall at 09:55 BJT on July 28 with a powerful intensity of 50 m s−1 confirmed by the real-time operational warnings issued by China Meteorological Administration(CMA).The typhoon also caused significant wind and rainfall impacts,with precipitation at several stations reaching historical extremes,ranking eighth in terms of total rainfall impact during the event.The evaluation of forecast accuracy for Doksuri suggests that Shanghai Multi-model Ensemble Method(SSTC)and Fengwu Model are the most effective for short-term track forecasts.Meanwhile,the forecasts from the European Centre for Medium-Range Weather Forecasts(ECMWF)and United Kingdom Meteorological Office(UKMO)are optimal for long-term predictions.It is worth noting that objective forecasts systematically underestimate the typhoon maximum intensity.The objective forecast is terribly poor when there is a sudden change in intensity.CMA-National Digital Forecast System(CMA-NDFS)provides a better reference value for typhoon accumulated rainfall forecasts,and regional models perform well in forecasting extreme rainfall.The analyses above assist forecasters in pinpointing challenges within typhoon predictions and gaining a comprehensive insight into the performance of each model.This improves the effective application of model products.

Effect of Elevated Temperatures on Inflammatory Cytokine Release:An In Vitro and Population-Based Study

Extreme high temperatures in the summer have become a global concern,and their risks to the inflammatory system have been largely unknown.Here we appraised the exposure risks of summer heatwaves by comparing the sera cytokine levels in healthy individuals under high and normal temperatures.In addition,we established a cell model with a 1.5°C temperature increase to investigate the regulatory mechanisms of temperature-related cytokines.Our results suggest that elevated temperatures enhance the release of interleukin-6(IL-6)and interleukin-8(IL-8)via the aryl hydrocarbon receptor(AhR)pathway and augment the proinflammatory effects of other factors.This suggests that we may have underestimated the impact of high temperatures on the health of individuals beyond just mortality rates.Moreover,seemingly minor temperature increases of just 1.5℃ can still pose a challenge to cells.

PERFORMANCE OF TROPICAL CYCLONE FORECAST IN WESTERN NORTH PACIFIC IN 2016

The forecasts of tropical cyclones(TC) in 2016 from 5 official guidances, 5 global models, 3 regional models and 6 ensemble systems were assessed to study the current capabilities of track and intensity forecasts for the western North Pacific. In 2016, the position errors for each official agency were under 85, 150 and 250 km at the lead times of 24, 48, and 72 h, respectively,indicating the performance of track forecasts was a little worse than that in 2015. For each lead time, decreases were seen for each quantile value of the global models from 2010 to 2015; however, this progress in forecasts was stagnated or was reversed in 2016, especially for long lead times.A new error tracking tool,called a "Track Error Rose",was used to visualize the spatial distributions of the track forecast error relative to the observed TC center. The results show that as lead time increases, the moving speed of most global model TC forecasts becomes slower than those of the observations, and the largest track error often appears to the south of the observation position. In 2016, JMA-GSM, NCEP-GFS, STI-GRAPES and UKMO-MetUM made considerable progress in their intensity forecasts at lead times of 24 and 48 h, and the EPS intensity forecasts made significant progress compared to those of 2015.

2021年7月河南极端暴雨过程概况及多尺度特征初探

2021年7月17~22日,河南省发生了致灾严重的极端暴雨过程,气象观测站最大6日累积降水量为1122.6 mm(鹤壁市),最大小时雨强高达201.9 mm(郑州市),突破了中国内陆小时雨强历史纪录.利用气象雨量站、探空和多普勒天气雷达等观测资料以及ERA5再分析资料对极端暴雨概况和多尺度特征进行了初探.结果表明,此次极端暴雨过程是在对流层高、中、低层以及中、低纬度多尺度大气系统共同作用,并叠加地形影响下产生的:(1)西南季风将南海的水汽向西北太平洋输送并经由热带气旋“烟花”向北抽吸,西北太平洋上的水汽经“烟花”北部的偏东低空急流和异常偏北偏强的副热带高压西南缘的东南气流向河南输送;这条异常的东进河南的热带气旋远距离接力水汽输送通道导致河南可降水量正异常.(2)对流层高层,河南位于短波槽前辐散区;对流层低层,河南及附近为低涡或倒槽影响,这些均有利于低层大气的辐合和上升.此外,伏牛和太行等山脉对水汽的汇聚和对低层偏东或东南气流的抬升有作用.(3)副热带高压和异常偏强的大陆高压连成“高压坝”,阻碍了中高纬度冷空气南下,郑州极端暴雨发生在暖湿层深厚的环境场中,降水系统呈现低质心热带型雷达回波特征.在郑州降水最为集中的2日内,新生对流不断从东南、南或西南方向并入团状的对流主体,使得中尺度对流系统长时间维持.

WMO TYPHOON LANDFALL FORECAST DEMONSTRATION PROJECT(WMO-TLFDP) PROGRESS AND FUTURE PLANS

The "WMO Typhoon Landfall Forecast Demonstration Project(TLFDP)" was started in May 2010 in conjunction with the start of the Shanghai World Expo 2010. The project was successful in terms of assisting the local forecasters in providing an efficient tropical cyclone(TC) forecast service for World Expo 2010, demonstrating the performance of the most up-to-date techniques in TC forecasting, and enhancing the ability of forecasters to effectively use products based on advanced TC forecasting techniques. The first phase was completed in December 2012 and the second phase was completed in December 2015. The third phase(TLFDP-III) started in 2016.During its first(2010-2012) and second(2013-2015) phases, TLFDP collected real-time TC forecast products from 15 Typhoon Forecast Product Providers(TFPPs). The products include deterministic track and intensity forecasts, ensemble track and intensity forecasts, deterministic wind radii forecasts, wind probability forecasts, and gridded model outputs. The products were disseminated through the project's website and the operational website of the Shanghai Typhoon Warning Center.TLFDP has made significant progress in TC forecast verification, including setting up the tools for both realtime and post-season TC forecast verification, developing and integrating several new verification techniques, carrying out a survey on the operational status of TC forecast verification in the western North Pacific region, and contributing to the WMO document "Verification of tropical cyclone forecasts". The post-season forecast verification was reported to the Session of the UNESCAP/WMO Typhoon Committee since 2013. New consensus methods for TC track and intensity forecasts were also proposed either based on Ensemble Prediction Systems(EPSs) products or multiple deterministic NWP model products. Two training workshops on TC forecasting were organized by the TLFDP and held in Shanghai, China, in May 2010 and June 2012, respectively, and seven research fellowship projects were implemented as jointly supported by the UNESCAP/WMO Typhoon Committee, Shanghai Typhoon Institute and Hong Kong Observatory.In its third phase(TLFDP-III, 2016-2018), the project will continue its effort on demonstration and evaluation of the newly developed forecasting techniques for TCs, and developing and documenting advanced guidance for the verification of TC forecasts, with special attention to TC intensity and precipitation.

EVALUATION OF TROPICAL CYCLONE FORECASTS FROM OPERATIONAL GLOBAL MODELS OVER THE WESTERN NORTH PACIFIC IN 2013

Tropical cyclones(TCs)forecasts from seven global models in 2013 were assessed to study the current capability of track and intensity forecast guidance over the western North Pacific.Analysis of along-and cross-track error revealed stepped decreases in the values of each quantile at each lead time level by showing the annual track error distribution from 2010 to 2013,particularly in the ECMWF-IFS,NCEP-GFS and UKMO-Met UM models.The TC propagation direction was much easier to handle for most of the global models;however,the propagation speed seemed to be more closely linked to the inner-core dynamics and thus processes that take place at smaller spatial scales.A new model evaluation tool,‘track error rose’,was used to analyze the models’systematic error in the track forecast using the same concepts as the‘wind rose’.The results showed that as the lead time increased,most of the global models forecast a TC moving speed that was slower than observations and the largest track error often appeared around the rear direction of the observation position.Another new model evaluation tool,the Taylor diagram,was used to evaluate the intensity predictions from the global models.A Taylor diagram provides a way of plotting standard deviation,centered root mean square,and the correlation coefficient on a two-dimensional graph,indicating how closely a predicted TC intensity matches observations.This made it easy to distinguish the intensity forecast performance of the seven global models and determine which models were in relatively good agreement with observations.Furthermore,it also provided a statistical measure of the correlation between modeled and observed TC intensity,offering a practical way of assessing and summarizing model capability.

PERFORMANCE OF TROPICAL CYCLONE FORECAST IN WESTERN NORTH PACIFIC IN 2015

The operational track and intensity forecast errors of tropical cyclones(TCs) over the western North Pacific in 2015 were evaluated on the basis of RSMC-Tokyo's "best-track" dataset. The results showed that position errors for each official agency were under 80 km, 130 km, 180 km, 260 km and 370 km at 24, 48, 72, 96 and 120 hr lead time. Stepped decreases in the values of each quantile were made at every lead times and have been made by global models from 2010 to 2015, especially for long lead time. The results of the Track Forecast Integral Deviation(TFID) show a clearly decreasing trend for most global models, indicating that the TC forecast tracks became increasingly similar to the observations. In 2015, the intensity forecast skill scores for both global and regional models were almost negative. However, the skill of EPSs' intensity forecasting has made significant progress in the past year.

THE PERFORMANCE OF GLOBAL MODELS IN TC TRACK FORECASTING OVER THE WESTERN NORTH PACIFIC FROM 2010 TO 2012

Forecasts of tropical cyclone(TC)tracks from six global models during 2010 and 2012 were assessed to study the current capability of track forecast guidance over the western North Pacific.To measure the performance of the global model forecasts,a series of statistical evaluations of track forecasts up to 120 h were carried out,including the mean,median,percentile distribution,regional distribution,relative position,correlation analysis,and binned analysis.Results showed that certain improvements have been made for the six global models in their prediction accuracy and stability in the past three years.Remarkably,stepped decreases in the values of each quantile were found at all lead time levels from 2010 to 2012 for NCEP-GFS.An analysis of the regional distribution of position errors showed that a high-latitude region,low-latitude region(which covers mostly the TC genesis region)and the South China Sea are the three main areas within which large errors tend to concentrate.The majority of the models show their own respective characteristics of systematic bias at each lead time,as established through the relative position analysis results.Only the results of NCEP-GFS and CMA-T639 did not show any obvious systematic bias in the three-year study period.Binned analyses indicated that the prediction accuracy and stability of most of the models were better for strong TCs than for weak TCs at short lead time levels.It was also found that the models tend to perform better for initially large TCs,or for those with weak vertical wind shear at lead times shorter than 48 h.The results demonstrate the heavy reliance of forecast errors upon the initial characteristics of a TC or its environmental conditions.

Three-dimensional cell culture models for investigating human viruses

Three-dimensional(3D) culture models are physiologically relevant, as they provide reproducible results, experimental flexibility and can be adapted for high-throughput experiments. Moreover,these models bridge the gap between traditional two-dimensional(2D) monolayer cultures and animal models. 3D culture systems have significantly advanced basic cell science and tissue engineering, especially in the fields of cell biology and physiology, stem cell research, regenerative medicine, cancer research, drug discovery, and gene and protein expression studies. In addition,3D models can provide unique insight into bacteriology, virology, parasitology and host-pathogen interactions. This review summarizes and analyzes recent progress in human virological research with 3D cell culture models. We discuss viral growth, replication, proliferation, infection, virus-host interactions and antiviral drugs in 3D culture models.

OVERVIEW OF SEVERE TYPHOON FITOW AND ITS OPERATIONAL FORECASTS

Severe typhoon Fitow(1323)brought persistent and heavy rainfall to Zhejiang and the Shanghai area after it made landfall at Fujian Province of China in October 2013,breaking the rainfall records of several counties and districts in Zhejiang.In this paper,we provide an overview of the characteristics of Fitow’s landfall,including its track,intensity,structural evolution,heavy rainfall,and wind.We also describe some of the associated disastrous impacts.Finally,we provide verifications of operational forecasts of its track,intensity and rainfall.Though the track and intensity is well predicted,the rainfall persistence and enhancement in the second stage in Shanghai and north Zhejiang areas are not predicted out at all.The analysis presented in this paper provides forecasters and researchers with some valuable information on Fitow,which could form a useful basis for further studies.

SARS-CoV-2 Aerosol Transmission Through Vertical Sanitary Drains in High-Rise Buildings--Shenzhen,Guangdong Province,China,March 2022

Summary What is already known about this topic?Aerosol transmission of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)via sanitary pipelines in high-rise buildings is possible,however,there is a lack of experimental evidence.

VERIFICATION OF ENSEMBLE TRACK FORECASTS OF TROPICAL CYCLONES DURING 2014

The track forecasts of fi ve ensemble prediction systems(JMA-WEPS,CMA-GEFS,ECMWF-EPS,NCEP-GEFS and MSC-CENS,respectively)in 2014 are evaluated in this paper.First,on the assumption of bivariate normal distribution,a probability ellipse based on ensemble spread is proposed to represent forecast uncertainties,and then the ellipse and ensemble mean are used to evaluate the fi ve different systems.It is found that the probability ellipse of ECMWF-EPS is smaller,with a high hit ratio,and its mean track errors are just a little larger than those of NCEP-GEFS within 48 h,meaning overall it outperforms the other four systems.Meanwhile,the performance of CMA-GEFS is found to be the poorest.

Track forecast:Operational capability and new techniques-Summary from the Tenth International Workshop on Tropical Cyclones(IWTC-10)

In this paper,we summarize findings from the Tenth International Workshop on Tropical Cyclones(IWTC-10)subgroup on operational track forecasting techniques and capability.The rate of improvement in the accuracy of official forecast tracks(OFTs)appears to be slowing down,at least for shorter lead times,where we may be approaching theoretical limits.Operational agencies continue to use consensus methods to produce the OFT with most continuing to rely on an unweighted consensus of four to nine NWP models.There continues to be limited use of weighted consensus techniques,which is likely a result of the skills and additional maintenance needed to support this approach.Improvements in the accuracy of ensemble mean tracks is leading to increased use of ensemble means in consensus tracks.Operational agencies are increasingly producing situation-dependent depictions of track uncertainty,rather than relying on a static depiction of track forecast certainty based on accuracy statistics from the preceding 5 years.This trend has been facilitated by the greater availability of ensemble NWP guidance,particularly vortex parameter files,and improved spread in ensembles.Despite improving spread-skill relationships,most ensemble NWP systems remain under spread.Hence many operational centers are looking to leverage“super-ensembles”(ensembles of ensembles)to ensure the full spread of location probability is captured.This is an important area of service development for multi-hazard impact-based warnings as it supports better decision making by emergency managers and the community in the face of uncertainty.©2023 The Shanghai Typhoon Institute of China Meteorological Administration.Publishing services by Elsevier B.V.on behalf of KeAi Communication Co.Ltd.This is an open access article under the CC BY-NC-ND license(http://creativecommons.org/licenses/by-nc-nd/4.0/).

A NEW VERIFICATION MEASURE FOR TROPICAL CYCLONE TRACK FORECASTS AND ITS EXPERIMENTAL APPLICATION

A new measure(the Track Forecast Integral Deviation;TFID) for the verification of tropical cyclone(TC) track forecasts is proposed,based on the mathematical consideration that a 'good' forecast has a small distance to the observed track not only at zero-order but also at higher orders.The TFID is the mean of two sub-scores,which are respectively calculated for latitude and longitude and defined to be the average value of the mean absolute error and mean absolute deviation of relative errors from the mean relative error along a track.By definition,the smaller the TFID,the more accurate the forecast track.A perfect forecast has zero TFID.It is suggested that such a measure is superior to the widely-used position error(PE) in terms of reflecting the accuracy of the whole track instead of just one position.In an experimental application,TFID was calculated for the track forecasts from the ECMWF-IFS during 2010-2012.A comparison with PE showed that TFID can work as a good supplement to the PE in discriminating good or bad track forecasts,as there are generally some forecasts with small PE but large TFID,or vice versa.The binned characteristics of TFID and PE of ECMWF-IFS were also analyzed based on several traits of the TC or its environment at the initial time of the forecast.It was found that the model performs better for initially strong and large TCs,or those with weak vertical wind shear at lead times shorter than 48 h.

Performance of tropical cyclone forecasts in the western North Pacific in 2017

The forecasts of tropical cyclones(TC)in 2017 from five official guides,six global models,six regional models and six ensemble systems were assessed to study the current capability of track and intensity forecasts for the western North Pacific.The results show that the position errors for official agencies were under 100,165,265,335 and 425 km at the lead times of 24,48,72,96 and 120 h,respectively.As the forecast lead times increased,the forecasted TCs propagated,on average,too slow for most official guides.It is encouraging to note that all the models had positive skill scores,there is an overall upward trend in the skill scores of the models during from 2010 to 2017.Furthermore,both global and regional models’intensity forecast skill was increasing year by year from 2010 to 2017.For the ensemble prediction systems(EPSs),ECMWF-EPS was the best forecast system for the lead time less than 72 h,beyond the 72 h,the best EPS belong to NCEP-GEFS.

Evaluation of forecast performance for Super Typhoon Lekima in 2019

The predictions for Super Typhoon Lekima(2019)have been evaluated from official forecasts,global models,regional models and ensemble prediction systems(EPSs)at lead times of 1–5 days.Track errors from most deterministic forecasts are smaller than their annual mean errors in 2019.Compared to the propagation speed,the propagation direction of Lekima(2019)was much easier to determine for the official agency and numerical weather prediction(NWP)models.The National Centers for Environmental Prediction Global Ensemble Forecast System(NCEP-GEFS),Japan Meteorological Agency Global Ensemble Prediction System(JMA-GEPS)and Meteorological Service of Canada Ensemble System(MSC-CENS)are underdispersed,and the Shanghai Typhoon Institute Typhoon Ensemble Data Assimilation and Prediction System(STI-TEDAPS)is overdispersed,while the ensemble prediction system from European Centre for Medium-Range Weather Forecasts(ECMWF)shows adequate dispersion at all lead times.Most deterministic forecasting methods underestimated the intensity of Lekima(2019),especially for the rapid intensification period after Lekima(2019)entered the East China Sea.All of the deterministic forecasts performed well at predicting the first landfall point at Wenling,Zhejiang Province with a lead time of 24 and 48 h.

A MULTI-MODEL CONSENSUS FORECAST TECHNIQUE FOR TROPICAL CYCLONE INTENSITY BASED ON MODEL OUTPUT CALIBRATION

We analyzed the errors associated with forecasts of tropical cyclone(TC) intensity from 2010-2012 in the western North Pacifi c region made by seven operational numerical weather prediction models. The results show that the forecast error is signifi cantly related to the initial error as well as the initial TC intensity, size, and translation speed. Other factors highly related to the forecast error include the environmental sea surface pressure, vertical wind shear and maximum potential intensity. We used stepwise regression to set up model forecast error estimation equations, which were used to calibrate the model output. Independent experiments showed that the calibrated model forecasts have signifi cant skill compared to the original model output. Finally, a multimodel consensus forecast technique for TC intensity was developed based on the calibrated model output;this technique has 28%(15-20%) skill at 12 h(24-72 h) compared to the climatology and persistence forecasts of TC intensity. This consensus technique has greater skill than the consensus forecast based on the original model output and therefore it has the potential to be applied in operation.